When I was specifying the build for my
Rivendell Sam Hillborne just over a year ago, I had no experience with these types of bikes, and went with recommended specs for the major components. For the most part, this has worked out well - with the possible exception of the drivetrain. This Spring I would like to replace the
Shimano Deore rear derailleur with the
Shimano XT "Shadow," and I am also wondering, whether I would be better off with a double, instead of my current triple crankset. I've mentioned before that I find shifting on this bicycle to be somewhat high maintenance for my taste, with the front derailleur being especially difficult to get into that perfect position where it doesn't rub. I am given to understand that this is fairly typical for a "triple," and that if I want low maintenance I need to switch to a double crankset. With just two chainrings in the front, there is more room and less rubbing.
Switching my triple crankset to a double is something I am willing to undergo, as long as I can keep my current
range of gears. This bicycle is used for hills, and I need to keep it that way. And while that is doable in theory, I am not sure what my options are as far as modern cranksets go. The chainrings on my current triple (
Sugino XD2) are 46x36x
2426 - so I would need to find a double crankset with just the 46x26 rings. Is that even possible? I know that it can be done with vintage-style TA cranksets, but I think I have a cognitive deficiency when it comes to understanding how exactly to buy those: It seems like every single part needs to be purchased from a different seller and they are all super-expensive and frequently out of stock. What other options are there? Someone has suggested simply removing the middle chainring from the current crankset, but I am pretty sure that's not how it's done. If you have a double with a wide touring range, I would love to know what your set-up is.
I personally haven't ridden a bike with a double all that frequently, but, It would seem to me you're going to have almost as much rubbing/trim adjustment as you would with a triple. You're front derailleur won't be getting any wider and you will still have the same width cassette in the rear.
ReplyDeleteAs far as vintage TA cranks go; I'm equally as baffled.
Good Luck
Are you sure you'd want to abandon the 36 and keep the granny gear? The 36 seems like a far more practical ring than the 24. I have two bikes with triples, and I have to admit I've never used the granny gear before on either. I'm not sure what kind of crank you have, or its bcd, but maybe you can replace the 36 with the 24, adjust the front derailer and turn it into a double crank? Or would that not solve your spacing problem?
ReplyDeleteAlso, although I don't have the mathey brain to figure this out, but I worry that if you keep a 24 and 46 ring, while removing the 36, you may be abandoning a rather large range of critical gears right in the middle. A double crank may necessitate changing to, say, a 30 and a 44 to maintain a fluid range of gears. Or maybe abandoning the 46 altogether, or the granny?
ReplyDeleteI'm not much of an expert either but dropping down 22 teeth from big to small chainrings is quite a jump. Most 'Compact Doubles' are usually something like 52x36. Obviously you could ditch the 52 in favour of a 48 if you wish, but I think the smallest ring you could get with a 110mm BCD (the outer bolts on the XD2) would be around 34-36. A smaller toothed chainring would necessitate to be placed on the inner spider bolts (74mm BCD for the XD2) which I don't think would work as you'd be missing the middle ring (I'd imagine the chain would just fall off and get stuck in between the two rings if you tried to shift).
ReplyDeleteOf course, this might all be nonsense, but I'm sure someone will correct me if it is. In which case, disregard everything :) (I'm still learning too!).
I'd consider trying a different front derailleur first. What are you using now? On a well set up triple it should not be difficult to prevent the front derailleur from rubbing. Cage designs differ, and it might be that you do not have an optimal front derailleur. Get the bike to a good mechanic who was around in the 1980s or earlier.
ReplyDeleteVelouria,
ReplyDeleteI don't have a double with a wide touring range, so I can't tell you about my set-up. But I hope you won't mind if I comment briefly on a couple of the issues you raise.
Although I've never tried it, it seems to me that simply removing the middle chainring would cause the chain to drop between the inner and outer ring while shifting. Maybe if the outer ring is ramped and pinned, it would pick up the chain eventually, but I'm not sure. I've shifter over an 18t (24-42) difference OK, but those chainrings were right next to each other, not separated by a gap where the middle chainring used to sit. You're looking at a 22t difference, which strikes me as being perhaps a bit too ambitious.
On the matter of high maintenance shifting, I wonder if your FD might have a cage that is narrower than optimal. I don't know what you have on the Hillborne, so this could be completely useless to you. But I once had a Suntour BL triple FD (half-step plus granny, actually) on one of my bikes, and I was forever having to trim the darned thing because the cage was so narrow. I swapped it out in favor of a Shimano XT 737, where the spacing between the inner and outer plates was greater, and now I hardly ever have to trim. If you're going to go with a new XT Shadow on the rear, maybe you want to match it on the front and just stay with your triple crankset?
The only bike I've built from the ground up has been a fixed-gear, but from what I understand I would think that you could take out the middle ring (switching out the bolts, of course) and fiddle with the derailleur. I could be completely wrong on that, though. I've been kinda intimidated to work on derailleurs so far, but am about to force myself to figure it out.
ReplyDeleteYou could definitely switch out your derailleur and then put together your chainrings a la carte. I don't know about most bike shops, but my LBS had a huge selection of old chainrings in the backroom which they let me choose between. They offered them to me for free, but that may have been because I was looking specifically at old Biopace (which the mechanic didn't believe would work on a fix until I assured him Sheldon Brown suggested it). Not a whole lot of demand for those, apparently. You should have no trouble buying chainring sizes you want separately from the cranks, though.
I'm looking at upgrading the drivetrain on my 80's Trek 1200 soon (most comfortable Al frame I've ever ridden, btw), so keep us posted on what you learn.
Im in the same spot as you are! Have, and allways had triples, just cos its recomended alot. Now I have decided to switch to a 42-28 fron (mbt standard) and have a 12-25 casette. Its plenty hilly here too!
ReplyDeleteI have used a triple for many years on my tourers and have never experienced the troubles you are describing. I have to say that I seldom use the granny ring, but even so when I do there's no rubbing.
ReplyDeleteI use XT derailleurs and a 46-36-24 chainring set up (on older Shimano XT cranks) on my expedition bike and 48-34-26 on TA Zephyr cranks on my light tourer. TA chainrings on both.
Are you really sure you need a 24 ring? That is very low. When I toured Wales last year I had to clear three mountain ranges and while mountains in Wales are not high they are very, very steep. I never needed my granny ring. i was travelling light, to be sure, just a Carradice Super-C saddlebag and handlebar bag, but I still did not need the small ring.
Are you sure you would need a 24 or some such often enough to make it your default second ring?
I have a compact road double on my Pegoretti (50-34) and with the 13-29 block on back have a huge range of gears - far bigger than I really need on such a light fast bike. I am sure you could do compacts with smaller big rings too. It might be something to consider.
If you want to make it clean, dump the front derailleur and two of the front rings, leaving just the middle ring. You are strong enough to not need the small ring and not being able to pedal downhill is no big deal.
ReplyDeleteHey Velouria,
ReplyDeleteI have the same bike and setup. I am just wondering what about the deore you don't like and what the advantage is of the shadow? I have had no problems with my rear derailler, and i'm just curious.
Also, as we live in a flat place, besides the big bridge i cross on my daily commute, i remain in my large chainring, and i never use my granny ring. I did find that my chain had stretched a little just through regular use and i adjusted my limit screw on the front derailler, it took quite a bit of tweaking to get it just to my liking, but now it's perfect. It was in this exercise I realized that with just a slight adjustment of the shifter up or down the front derailler moved equally slightly to allow the chain to spin freely and without any rubbing.
It is my understanding in order to switch to a double chainring then you've got to also change your rear cassette, and i can't imagine you wouldn't lose some great middle gears with such great differences of size in the front. Once again, I'm no expert I am interested to hear what other foks comment.
PS For what it's worth, I love your posts about technical info in componentry, frame geometry, etc, I always feel like I learn so much from the experience and expertise of all the great readers that weigh in.
Funny you should mention the shifting issues with your Hillborne. I love my Hillborne, but have had issues with gears skipping and jumping cogs since the bike was new. This happens often in the 3rd and 4th rear cogs which I use frequently. It is especially annoying when climbing. And like you, I have also considered the double chain ring setup, but mostly because I haven't used the small cog enough to justify it. Even on my biggest hills, the middle rings suffice. I have seen some of those early French style bikes with doubles that have a very small inner ring. Perhaps something like that would give you the range you're looking for.
ReplyDeleteBTW, I noticed your comment on the Velo-Orange blog about wanting the last Mixte. I don't think they respond to comments regularly, so if you are interested in the bike, I suggest you send them an email. I'm sure they would love to sell it to you at very reasonable terms because of the exposure your write-ups would give V-O. Could you please delete this paragraph prior to posting the reply?
You could go with a compact double (a road crank with a 110 BCD), but your smaller ring will only be around a 34T. Swapping your cassette to a 12-36 in combination with a compact double (typically 34/50) would give you a range of approximately 25-112 inches. You didn't mention the range of your current cassette, but assuming 11-32 in combination with your 24/36/46 triple gives you approximately 20-112 inches, so you'd be giving up 5 inches on the low end.
ReplyDeleteIf that's not acceptable, you could simply replace your 46T ring with a Sugino bashguard (this is what Michael did on her Betty Foy), which would keep your low range intact.
http://www.rivbike.com/products/show/sugino-chainring-guard/12-276
Going this route would mean less on the high end and more coasting downhill - not necessarily a bad thing! :-)
Alan
The TA can only go as low as 26, not 24. I am not aware of any other double that has the range of a TA crank other than the Sugino PX and they are out of production and hard to find. The shift from 26 to 46 is o.k. but not at all like the shift from 36 to 46.
ReplyDeleteYou can move your 46t into the position of the 36t. You will need some shorter bolts, which you can purchase, or add spacer washers and keep the current bolts. The chain will now run more to the center of the rear cogs, so there is a better chain line when you use all of the rear cogs with the 46t ring. In other words when you use your 46t with your largest rear cog the chain line will be less angled. This would be a cheap fix to see if you like this setup. You can do many changes with bicycles without investing alot of money; it's a fun and rewarding challange.
ReplyDeleteChris
It may be necessary to change the rear cassette, too, in order to keep the same feel. You want the "gear inches" to stay the same, which can be done with a number of combinations. There's a formula for calculating gear inches, but I don't know it off hand.
ReplyDeleteOf course, it gets expensive to change a whole drivetrain, so hopefully someone will have the exact thing you need.
I often have to adjust my front gear *just so* to stop the metal thing from rubbing against the chain. This doesn't bother me enough to change the set up, but I'll be interested to hear how the double chainring works for you.
ReplyDeleteI've ridden triples for years and really don't like them much. With a double you either shift all the way or all the way down — no tedious middle position. Try to figure out what gear-inch range you really need on that bike and work from there. My son has a vintage MTB set up with a 28/46 double and it shifts fine.
ReplyDeleteI run single Sugino chainring setups on bikes for my wife and children. Two of the cranks are doubles and two are triples. The rings are all in the second position and work fine. You can switch the 46t and 36t around to suit your needs and still run the 24 as a bail-out, which is a good idea. Also you can experiment with a chainring between the 36 and 46 like a 40 or 42 for around $30.00 or less.
ReplyDeleteChris
Thanks for the replies!
ReplyDeleteRegarding which rings to keep: Yes, I am sure I need the small ring. If anything, it's the 46t ring that's not really necessary since I am never in a steep downhill+tailwind situation. So maybe a 24t ring for the granny gear plus something in between the 36t and 46t for the larger ring?...
Indexed shifting.
ReplyDeleteOr is that somehow blasphemous?
TA Zephyr, Sugino Alpina and other cranks with 110 BCD (bolt circle diameter) can take a 33 tooth chainring. TA makes the ring in that size.
ReplyDeleteI think people who put TA Vis 5 (a.k.a., le Cyclotouriste or the "vintage" or "classic" crankset) spend half of their lives on eBay and at swap meets to acquire the necessary parts. Velo Orange has a crankset that takes the same chainrings as those old TA cranksets, with the same gear ranges. But they're also made to be used with modern front derailleurs and chains. Best of all (from your point of view), you can buy a complete set and not have to spend time hunting down the parts.
Another possibility is a mountain biker's trick: Use the middle and inner position on your current crankset. Keep the inner ring, and use the outer ring on the middle position. And get a "disc" chainguard to use in place of your outer ring. Just find one that's made for 110 BCD cranks and is big enough to cover your larger chainring. BBG in Oregon makes some nice ones that are neither tacky nor expensive.
The setup I've just described is the same as what you'll find on the Velo Orange Polyvalent crankset. The only difference is that one comes with a 30T small chainring--which is easily replaceable with one as small as 24 teeth, as it is 74 BCD.
If you do choose to make the modification I've described--or pursue any other option for wide-range doubles--think about which gears you're using now. Do you actually use your highest gear on anything but the steepest downhills. If you don't, you might want to consider going with a slightly smaller large chainring, like a 44, 42 or even 40. Because your crankset is 110 BCD for the outer two rings (and 74 BCD for the inner), you will have a wide variety of options available, some of them inexpensive but good.
By the same token, think about whether you really need your lowest gear, or whether you might want even smaller. You could set up your current crank with something like a 46-30, 44-28, 42-26 or 40-24.
One nice thing about this setup is that you probably won't have to change the length of your bottom bracket axle, and you could probably use your front derailleur. (You'll just need to adjust it.) Even if you bought two new chainrings and a guard, you could spend considerably less than if you bought a new crankset and get something that will work--and look--just as well.
We'll have to change the bottom bracket, front derailer, crankset and rear derailer.
ReplyDeleteIf we find a 26/28-something double we'll keep the current cassette. Otherwise, if we end up getting a 32-something double we'll change the rear cassette so that the biggest cog there is a 34 as well (similarly to the Royal H mixte setup, in fact we may duplicate that drive train).
I like the XT Shadow and if anyone is having shifting/skipping problems on a Hillborne-style bike that is definitely the cure. I happen to think that the current rear derailer we have on this bike is dumpy.
There is also the option of going with VO TA-style repro cranks, which I am really hoping to hear comments about here after VO & TA- aficionadi wake up. :)
Do ever use the 24 in combo with the largest cog on the cassette? How many teeth does that cog have?
ReplyDeleteThe advantage of the 24 is that you can shift to it while remaining in the middle of your cassette. It's your low-range in 4x4 terms.
ReplyDeleteImagine you have a double and an 8-speed cassette. In regular cycling you stay in your normal gear, which can be 46 or 48 and use the rear derailer to shift. That's sufficient for anything Boston & suburbs have to offer. But if you find yourself on, say Cape Cod or--even better--D2R2 territory, well, low range then.
In that sense the ideal crankset with be one of 24/26/26 by one of 46/48/50 depending on individual preferences. Unfortunately, other than recent VO or vintage TA, I don't think these exist...
I wonder if the rubbing issue is because the front derailleur cage was tweaked and is out of alignment or perhaps bent. Friction shifting allows for easy trimming, as you know, but the sound of a chain rubbing on a derailleur cage drives me batty. Looking forward to reading how you resolve it. Good luck!
ReplyDeleteMDI, I see your point. I don't ride that way, riding the larger of two rings on my mtb nearly always, then dumping to the little/big combo directly from the big/big combo when going up, mostly because chain tension can be an issue when it's rocky. With the new rear derailleur that shouldn't be a problem for V's bike.
ReplyDeleteSeems like the VO repro is the natural choice, though not cheap. Pending a negative review what could go wrong? It's a crank.
ann ladson said...
ReplyDelete"I have the same bike and setup. I am just wondering what about the deore you don't like and what the advantage is of the shadow? I have had no problems with my rear derailler"
I think that whether you need the "shadow" derailleur depends largely on how you ride the bike. The benefit of the "shadow" is that its design keeps it tucked in, closer to the bike - making it less likely to get caught on stuff, or for stuff to hit it. In the course of last summer I banged up my existing derailleur pretty badly as a result of it being hit with road debris, rocks and gravel that flew from under my tires. Also, compared to the Shadow (which I have on my mixte) the Deore derailleur jiggles more when going over bumps and potholes at high speeds - all of which I do on this bike.
I have triples on all my derailleur bikes (except the folder) and sure end up using all the gears, depending on where I am travelling. I have never had any rubbing issues and they don't seem at all finicky to me, but they are all index shifting, not friction. Perhaps it is the combination of your components. I did not choose mine myself, just the gear range and trusted my mechanic to set it up so I could forget about it, which I have. Even after many miles with fairly poor maintainance on my part, there is always flawless shifting, no rubbing and I love my triples. Haven't used a double in a very long time and would never go back.
ReplyDeleteHi Velouria,
ReplyDeleteI have a Hillbourne with a Sugino 46/36/24 and an 8 cassette in the back 11-32. For my Pelican, which is my distance Rando Bike, I talked to the guys a Box Dog Bikes and they recommended a Velo Orange double, which VO describes as '46/30 rings which offer the range of a triple with less shifting and lower weight.'
This one: http://store.velo-orange.com/index.php/components/cranksets/grand-cru-50-4bcd-crankset.html
and a 9 speed 11-32 cassette in the back. (SRAM PG950)
I live in San Francisco, where there is no avoiding the hills. This setup effing rocks.
xoxo,
Alice
I like the idea of changing out your rear cassette to have a 36 to add to your low end, and then using a compact double.
ReplyDeleteBut I would consult with the Riv squad, since they are specialists in their bikes!
Box Dog rocks.
ReplyDeleteHi Velouria
ReplyDeleteMethinks Justines advice is quite sound.
Otherwise: the advice I would give to somebody in your situation is to ask oneself a few questions. Which is the highest gear I really need (and remember Eddy Merckx competed on 52/14, most of us mortals need far less)? The lowest? What gap do I like between gears? So, how many gears do I really need?
Then I would go to Sheldon Browns gear calculator to play around and see what is the simplest combination for my needs? Why not try VOs 46-30 combination and see what happens?
And remember, standard combinations on chainwheels and cassettes are exampels, there is nothing wrong (and much funnier) to go custom. And why not ask Harris? They do sell the TAs, even have a deal on 165mms right now.
I have never used three chainwheels during a long life of bicycling including loaded camping in hilly terrain, cannot see the use (and I like half-step, but you cannot say that to an American or they panic ...).
Rather than spend all that $ on new parts (aside from the r. derailleur) have you looked into replacing the front derailleur with one that has a slightly wider cage? That would reduce the amount of trimming needed. Perhaps the existing cage can be mechanically widened.
ReplyDeleteAdditionally some friction shifters slip and go out of adjustment if the tension screw isn't just so.
The combo of these might lead to a tolerable result.
I would tend to agree strongly with some of the above comments. Firstly, I would ask what it really is that bothers you about your drivetrain: is it the fussiness? The noisiness? The jiggling? Ghost shifting? If you like the gearing but feel that it's too "fussy", then switching to a double may not be the solution.
ReplyDeleteAlso, I don't agree with MDI's opinion about the Deore RD-- although it is a mid-range derailleur, it is a tried and true piece of equipment, and Anthony King of Long Leaf Bicycles wouldn't tock it and recommend it if it weren't solid. Typically, derailleurs only begin to act up when they are bent, or when the dropout becomes bent, when they are out of adjustment, or the chain doesn't have enough tension.
I would ask questions pertaining to the design and installation of your drivetrain, as well: was consideration given into chainline? (i.e., was the bottom bracket specifically matched to the crankset chosen? Was the chain properly measured and is the length appropriate for the desired derailleur tension? Both of these if not carefully accounted for can lead to "fussiness" in the drivetrain. The fact that the RD "jiggles" when you go over pumps tells me that perhaps there are one or two links too many on your chain. Have you tried seeing how much excess derailleur travel you have when you have the largest front and rear cogs chosen? The RD should be stretched to near its limit.
I also second the idea of simply swapping out the FD for one with a wider cage. The vintage Huret Jubilee FD I have doesn't scrape the chain at all, regardless of what cog I'm in (with a modern 8-speed cassette). I set it once and forget it.
I do like my TA compact double (46/26). I think the smallest granny you can get for it is 26.
Also, before deciding that you need a 24T, or a 26T, or whatever, you should really be figuring out the math in terms of gear inches-- because wheel size, cassette size and front chainring size all contribute to gearing. Once you know how many gear inches you need, you can figure out what combination of front rings and rear cogs you need to achieve it.
somervillain said...
ReplyDelete"Firstly, I would ask what it really is that bothers you about your drivetrain: is it the fussiness? The noisiness? The jiggling? Ghost shifting?
Fussiness, jiggling, and occasional ghost shifting. Not noisiness. Also, I don't think I've ever used the large chainring. I use mostly the 36t, occasionally switching to the 24t - on prolongued uphills.
somervillain said...
"Also, I don't agree with MDI's opinion about the Deore RD-- although it is a mid-range derailleur, it is a tried and true piece of equipment"
He and I have a difference of opinion regarding the derailleur issue. My theory is that I damaged it by hitting it on the edge of a particularly monstrous, ditch-like pothole I went over sometime late last summer. He insists that is not the case, because the derailleur does not look damaged, and thinks that the derailleur is just inherently not that good. Either way, the "Shadow" should be a better choice, as it's more immune to both jiggling and getting snagged on stuff.
Regarding checking for all the potential problems you and others have listed (chainline, bent front derailleur, shifter tension, etc.) - Yup, we've checked for all that. Nothing wrong.
Diagnosing bike problems over the internet is impossible. If you have a mechanic you trust go with him/her. Otherwise all of us well-meaning posters will be handicapped by the lack of meaningful information. You did ask a specific question about what others are using but sometimes you present a specific question based upon a wrong diagnosis or assumption.
ReplyDeleteIt'd be nice if we have the above info from your latest comment in the body of the post, rather than find it after 35 comments. It'd also be nice to know the resolution of the problem.
You know for sure the shifter isn't slipping after hitting massive potholes? I don't care who makes them friction shifters slip because they are FRICTION shifters. I have them, they slip and require trimming. The more speeds you have the more trimming you have to do. One of my friction shifters require so much screw tension so they don't slip so much as to make them impossible to use with a a thumb or one finger. My whole hand has to come off the bar to move it. And I'm not weak.
I've now gone back and read pretty much every post you've made along with almost all the comments. Yup, I did. Not once, despite numerous comments suggesting to check tire pressure and gear inch calculators out, have you indicated you've done so. To ask a nuts and bolts-related question you have to crunch the numbers.
Please tell me you have a tire pressure gauge and us it.
http://whbikes.wordpress.com/2010/02/03/ebisu-all-purpose-part-iv/
ReplyDeleteGR Jim - I don't think so. I did not ask anyone to solve derailleur problems that may or may not be there (most likely not, as we can find no evidence for them), so that information was really just shared in a chatty sort of way, and I intentionally did not include it in the post. I was specifically interested in what kind of "touring setups" people use, and thought this info might be appreciated by other readers also.
ReplyDelete"I've now gone back and read pretty much every post you've made along with almost all the comments. Yup, I did."
My condolences for that.
Nonetheless, I will write about gear inches when I am ready to write about that. Don't bully me.
Not bullying you, criticising your methodology. Not in this post, but in some others.
ReplyDeleteOk, it's your money and you can spend it on any sort of component you like.
Surprised you let the MDI snarky comment through.
^ I deleted them both once I noticed. Fini.
ReplyDeleteMy tone was peeved because I need to understand the motivation behind a question.
ReplyDeleteI can respect a man who stands up for his gal.
I can also respect a man who realizes he's not Sheldon Brown. He may be right but I'd certainly want a second opinion in the real world before throwing money at the problem.
Now that MDI has been outed I will keep that in mind when commenting in the future.
Context is everything.
What do you mean outed? You mean you just found out?
ReplyDeleteBy the way, it was Sheldon Brown's shop (Harris) that set this bike up, not me.
Jim - This is really getting too much for me. His is not the only opinion I've had about my drivetrain. Also he is not "outed" but has been commenting here as MDI since the start of this blog. Visit him also at Boston Retro Wheelmen and on his flickr account.
ReplyDeleteNow, hopefully FINI for realz.
Justine Valinotti said...
ReplyDelete"I think people who put TA Vis 5 (a.k.a., le Cyclotouriste or the "vintage" or "classic" crankset) spend half of their lives on eBay and at swap meets to acquire the necessary parts..."
Yes, that's the impression I get when I try to look into it!
"Another possibility is a mountain biker's trick: Use the middle and inner position on your current crankset. Keep the inner ring, and use the outer ring on the middle position. And get a "disc" chainguard to use in place of your outer ring."
Okay, regarding this: If this works, I think it would be the best and least costly option. But do you know why it is that some recommend against it? I've been told it is a bad idea, but the elaborations have been vague, or at least too vague for me to understand.
You mean I'm the last to know? I guess some details get left out when trying to cram the contents of this epic blog into my brain.
ReplyDeleteRe: SB. That's actually funny.
O hai. My Surly LHT came with a 26-36-48 triple and an 11-34 cassette. After a while I figured out that I was spending most of my time in relative small cogs when on the 36 and middle-ish cogs when on the 48. In other words, I was shifting a lot between the middle and large chain rings.
ReplyDeleteBuilding on Justine's comment, try to simply replace the middle ring with a 38 or 40, but instead of removing the large ring, leave it there for those wonderfully long downhill runs.
A couple technical issues. Try not to make the difference between the small and the middle rings too great. You run a risk of reducing the usable cassette cogs when on the small ring, because the chain will "drag" on the middle ring if there's too much of a chain angle. Also, if your middle ring is close in size to the larger ring, say 4 teeth or so, you may not be able to use a triple front derailer. The inner part of the cage will contact the middle ring when the chain is shifter to the larger. You're not going for a half-step-plus-granny here, but rather a compact double with a "road ring". :)
One of my bikes has a 34-50 double and a typical 13-28 7-speed rear. Chainline is fairly straight, with the gap between the rings lining up with the 4th gear in the back, within a millimeter or so. The 34 is only usable with the largest 3 or 4 cogs. Any more chain crossover than that and it will contact the larger ring. If I ever get around to it, I may put a slightly wider bottom bracket on this bike, since I'd rather have a greater range on the small ring than the ability to run the large cogs with the large ring.
Hit me up if you need me to clarify anything.
Jules said...
ReplyDelete"I'd consider trying a different front derailleur first. What are you using now? On a well set up triple it should not be difficult to prevent the front derailleur from rubbing."
It's a Shimano Sora, which is supposed to be decent (but MDI disagrees).
I think that is sort of the crux of my conflict. Some say that if I replace my rear and front derailleur with "better" versions, as well as perhaps the shifters with indexed shifters, my problems will go away. Others say that doing that would just be wasting money, because my problems are inherent to (even the best) triple drivetrains. So... I don't know, but converting to a double almost seems like the safer thing to do, financially. The last thing I'd want would be to replace my rear derailleur, front derailleur, and shifters, and still be where I am now.
Velouria - Make Sheldon's gear calculator your friend.
ReplyDeletehttp://www.sheldonbrown.com/gears/
Triple front road cranks are always a bit more sluggish and prone to rubbing than their double-ringed brethren, and while some can be set up beautifully, most require quite a bit of compromise.
ReplyDeleteI've usually recommended a compact double for everything except racing and loaded touring (when possible, that is, most of our entry-level road bikes come with a triple as the only option). With a generously-sized cassette, you can usually get as low a gear as you'll ever need, and the simpler mechanics and shorter travel distance of the double front derailleur tend to be less finicky.
My only concern is if you've got the "typical build" listed on the Rivbike site, you might already have a 32 as your biggest cog, leaving you without too much lower to go in the rear, if you really need those low gears, you might have a harder time getting then with a double crank.
Tony - Sheldon's calculator does not have an option for my 650Bx42mm tires, so I have to approximate using the closest option (650Bx38mm) tires. According to this method my range is 21.1 - 108.7 gear inches.
ReplyDeleteAlso, apologies but I made an error in the post: My smallest ring is indeed 26t and not 24t. I was looking at the online description of the crankset on Rivendell's site instead of at my actual crankset. I will change this via strikethrough in the text.
I understand your frustration with a friction shifted front triple. I have one, and it can be maddening to constantly trim the middle ring depending on the rear cog used. Index shifting is a godsend for that.
ReplyDeleteIf you have truly never used the large chainring, as you say in one of the comments, see if you can't adjust the limit screw on the front derailleur such that it shifts as a double with only the smaller two. That way there is no trimming involved with the 36.
As far as the rear derailleur goes, even a non series Shimano found on a BSO will shift reliably for a very long time, provided something doesn't become bent, and the cables are operating smoothly. If there is friction between the cables and housing, the performance can get balky.
somervillain said...
ReplyDelete"I do like my TA compact double (46/26). I think the smallest granny you can get for it is 26."
So apparently that is the range I would need. But your TA crankset is vintage, right?
Also, can somebody clarify the concept of a compact double? I thought it was when the rings are closer together, such as 46x36, which would make 46x26 more like a "wide double"...
Scott Loveless - Your Surly is similar to my setup. My rear cassette is 11-32. I spend most of my time in the middle chainring, using the smaller-to-mid range of cogs. When we go out on a ride with substantial climbs, I start to use the larger cogs, and occasionally switch to the small chainring.
ReplyDeleteI am trying to understand yours & SJP's suggestion regarding leaving the large chainring on but adjusting the derailleur not to shift to it. Didn't think it was possible to do that.
The "compact" refers to the bolt circle diameter. Old standard BCD was 144mm, and the compact is 110mm.
ReplyDeleteThe 144mm BCD constrained the smallness of the inner chainring to something like 42 teeth, but provided a torsionally firm 53t. A 110mm compact double allows for a smaller inner chainring, but has historically limited the size of the large one at 50t due to deflection.
I have triple just like your Sam on my Waterford Touring Bike, and a compact double on my Bianchi Limited sports touring all-around road bike. I made a big long Compact Double post, like what a few others have written, it bounce cause it was too big. So I emailed it. In essence I really find mine useful and overall it's good.
ReplyDeleteA compact double is simply one in which the bolt circle diameter (BCD) is 110 mm, rather than the typical 135 mm (Campagnolo and its clones) or 130 mm (almost every other brand) road double crankset. The smaller BCD allows for the use of smaller chainrings: Most manufacturers make 34 tooth rings, while TA makes a nice 33 tooth.
ReplyDeleteYour crankset has a 110 BCD for its outer two chainrings. The inner is 74 BCD. So, if you like, you can think of a "compact double" as your crankset without the inner ring.
As for my suggestion of using the inner and middle chainrings: I'm not so sure of what could be wrong with it, as long as your derailleur is adjusted properly. If anything, it has benefits over a triple or a regular double. On a triple, the middle chainring gives the straightest or "neutral" chainline. (It's more or less like using a single front chainring.) If you set up your gears so that you're using the larger (middle) most of the time, this should actually decrease the wear, and improve the performance of, your drivetrain parts.
I know that the purists hate these sorts of solutions, but I and other people have done what I described and had no problems.
Thanks re the compact double clarification.
ReplyDeleteThanks Chris, I got your email.
Reading all the comments here has made me rethink my claim of needing the entire range of my current triple. If I never use the large ring, then why indeed do I need it? My instinctive answer is "just in case" but that's not logical. I just wrote than I spend most of my time in the middle chainring, so it seems best to keep the middle one (or replace it with a slightly larger one) and get rid of the large one, as some have suggested. So maybe a 38x26 or 40x26...
"Compact" double cranksets have a smaller bolt-circle diameter than "Standard" road cranks (110 vs 130). That is, the spacing between chainring bolts is more compact, which allows you to fit a smaller chainring on the inside, allowing for lower gearing.
ReplyDeleteThis setup has become more popular recently on road bikes, but has been around for ages on cyclocross bikes.
Also, speaking as an occasionally professional bike mechanic (part time these days, but I've been doing it on and off for more than a decade) Sora front derailleurs are pretty crummy. They're flimsy and tend to rub a lot. If you're going to replace it, go for 105, it's not nearly as superlight and expensive as the "race ready" stuff (Ultegra, Dura-Ace) but will work well and last almost as long.
I promised myself not to get back in but...
ReplyDeleteMDI and Matt are right - I'm surprised the Sora was spec'd as the standard FD on this build. The cost of the frameset alone demands a few more dollars invested in the FD.
Not using the large chainring will get you the gear range you use, but won't solve the rubbing FD prob.
Matt/ Jim - You really think the Sora can be causing this? I guess I am willing to sacrifice $35-40 to experiment with a different front derailleur. Is the 105 better than the IRD?
ReplyDeleteStill, I am haunted by those who say that even with the best triple set-up there is rubbing and finickiness...
If there's a metallic noise it's probably the chain rubbing on the FD. The ghost shifting and other stuff is probably not enough spring tension in the RD and a better new one will fix that prob. if the chain length is good.
ReplyDeleteI'm going to go through your archives now to look at your FD mount...
I am pretty sure you will find any triple rub-prone, regardless what anyone says here. So, your only real choice here is the full monty, incidentally the same setup that works so well on the Royal H mixte: new BB, Alpina 34/46, IRD CD w/ bracket, XT Shadow and a new 13-34 cassette. We can start by just getting the new derailers front/rear and seeing how that feels.
ReplyDelete(...forgot to remind you that the IRD CD will solve your front shifting problem because the long silver shifter will point down all the time, since IRD CD shifts upside down, going to small ring by default...)
ReplyDeleteIt's likely not the derailleur that's causing the finickiness in the middle position- it's just the nature of the beast.
ReplyDeleteI had a finicky front microshifted triple (think friction but with exciting clicky noises) that I converted to indexed shifting and then never had another issue with it. I had full range shifting capability with no clatter on a 7 speed rear while in the middle chainring. Oh, and this was on a BSO, replete with it's craptastic front derailleur.
I'm going to have to kind of concur w/MDI 10:35 that it's true w/friction shifters, less so w/index.
ReplyDeleteIt looks like your FD is clamp-mounted and it will cost a bit.
What I would do...is get something like this: http://shop.ebay.com/?_from=R40&_trksid=p5197.m570.l1313&_nkw=shimano+deore+xt+front+derailleur&_sacat=See-All-Categories
from either a local co-op or ebay, try it out. Must be used and cheap. If it works, great you can keep it or resell it. If you think it's ugly and it works measure the width of the inside and find out if a Huret is that wide. SomerV says it works, so maybe bid on one.
Ground Round Jim:
ReplyDeleteThe ghost shifting and other stuff is probably not enough spring tension in the RD and a better new one will fix that prob. if the chain length is good.
This is what I said way earlier; it amazes me no one else suggested this.
Justine and Scott have come up with the best idea. A 26T inner and the 36T or a new 40T middle, while either ditching completely or putting a bash-ring on the outer would give good shifting and a wide range of gearing. I missed if you mentioned what the rear cassette is, but if it's and 11-30, you'll still have plenty of high gear when in 40X11. Even a 40X13 isn't bad if you currently aren't using your 46T ring at all! If you don't use a bash-ring outer, you'll also need to get some BMX/singlespeed type shorter chaingring bolts as you will only have one ring on the cranks.
ReplyDeleteI also can't believe that they spec'd a Sora for that bike. Some would argue that the quality of a front derailleur isn't as important as that of the rear derailleur or some other components. While I agree, I think there is a minimum threshold of quality you should have, especially for such a good bike. And the Sora does not meet that threshold.
ReplyDeleteSo, I'd get at least a 105 front for that frame. I've never tried an IRD, but I hear that it's good. Either one costs about ten or fifteen dollars more than a Sora when purchased a la carte. (I must say, though, almost nobody purchases Sora components that way: They're almost always OEM, or original equipment from the manufacturer.)
Even with a better front derailleur, though, you'll have easier shifting with a double. That's one of the reasons why I switched back to a double on my road/audax bike. And, yes, it's a compact double.
I've had triple setups with STI and Ergo shifters, on road, cyclocross and mountain bikes. I actually came to prefer non-indexed shifting for the front, as sometimes it is necessary to "trim" the front derailleur after a rear shift. That is not possible with an indexed system.
Front derailleur quality notwithstanding, I'd still switch to a double if you can get the gears you need from it.
I would not worry about your front derailleur. THey are all pretty basic and that is all they need to be. As long as it is set up correctly and the cage is parallel to the chain line, you should be fine.
ReplyDeleteChances are your trouble is with the RD or your chain is too long or a combination of things. Do you have a long cage RD? If your front range is 46-26 and your rear is, say, 11-34 you may be exceeding the capacity of your RD and that could be causing issues. And yes, you may have damaged it and/or it may be poorly adjusted. A Deore RD should be pretty low maintenance unless you are really being rough.
What about your cables? How old (and clean) are they? I use a sealed system on by bikes (Transfil or Gore Ride On) and that reduces a lot of bother. A bit of dirt working its way into the housing can cause problems.
How worn is your chain? And is it the correct length? I am not familiar with the geometry of your bike but with long chainstays, a 46 big ring and a 34 rear, a standard chain may be too short and it is possible that in lengthening (if it did indeed require lengthening) someone added too many links.
Your description of jiggling, ghost shifting etc which wasn't mentioned in the original post definitely leads me to think there is something wrong with your set up, not an inherent fault with triples.
There are a lot of thing you should look at before you start making big changes to the drivetrain.
I run a 52-42-30 triple and out of curiousity, tried what Anonymous Chris recommended earlier. It's an easy enough experiment to try, no need to even remove the crank.
ReplyDeleteI swapped the large and middle chainrings, and shifted only between the the 52 and 30. Shifting to the small ring brought a lot of clanking and a huge and sudden drop in gearing. I couldn't get it to climb up onto the big ring though. I used my triple FD because a road double FD couldn't accomodate the 30.
These are not the same as your 46-26, but you may end up with the same results.
I think you should get rid of the "round the world casette" and settle on one closer spaced like I have this year. My logic is, if I dont use all that range, and I do not, why not have one with smaller steps; allowing me to keep the perfect momentum. So far it feels like an improvement, although this season is still very young.
ReplyDeleteWhat is IRD? RD is rear Der. and FD fron Der. I get, but IRD? Is it Indexed?
As some suggest, getting rit of the outer ring, can make a tripple act as a double, but will chainline be ok!? the highest gear on the RD will be far starboard.
I just saw this post and want to agree with some of whats being said, I wonder if the tuning of the current set-up is really ideal. Spring tension, chain length etc. are going to be critical with any triple and there aren't any "rules of thumb" or "standard" set-up procedures that ensure proper function.
ReplyDeleteThe symptom that really brings this up in the front is the rubbing. Derailleur height and alignment with the rings are something that really needs to be played around with sometimes, especially with a mix and match approach to componants. You may have already done this on your bike but sometimes people give up on triples before they exhaust the possibilities. The triple on my mountain bike works best with the front derailleur rotated slightly, people(OK, men)are always telling me I need to fix that and I just say"I know, I need to get around to that" because I got tired of being told the cage always needs to be parallel with the chainrings. But it does work, on my bike.
Spindizzy
By the way, in reference to a couple of posts I've seen, derailleurs are not indexed; shifters are indexed. Derailleurs are 'dumb' in that they do only what the shifter tells them to do. Thus they are not speed specific.
ReplyDeleteAgain, I would look to your chain, the cleanliness and age of your cables, consider the possibility of a bent derailleur hanger, and check the capacity of your rear derailleur against the size of sprockets and chainrings you are running.
I would do all of these things before plunging in and changing things wholesale on your drivetrain - unless a new drivetrain is really what you have your heart set upon
For the record, I've never called a derailleur indexed : )
ReplyDeleteI know you didn't - I saw a couple of cloudy remarks further up that suggested some people were of that impression.
ReplyDeleteYou watch though: someone will now come along and post a link to an exotic derailleur that is indexed...
ReplyDeleteI agree w/Spindiz regarding slight FD clamp rotation and height adjustments.
ReplyDeleteAs some data points we have 5 triples in the fam that are prob-free, running 3x7, 3x7, 3x9, 3x9, 3x9.
re: indexed FD shifting. Two of the bikes have trimmable indexed FDs, both mountain bikes.
Roff - I had to go back and look to make sure I didn't say that. Whew.
"Two of the bikes have trimmable indexed FDs, both mountain bikes." Argh. Need second cup of coffee.
ReplyDeleteJan Hein at Bicycle Quarterly just did a review of the VO 50.4 bcd crank.
ReplyDeleteConclusion: "...Keep a close eye on the arms for corrosion cracking."
Man, I had this nice comment all typed out that (sort of) made sense and then Google/Blogger deleted it.
ReplyDeleteBasically, your post encouraged me to ask about how important the condition of the front and rear dereilleurs are to the ride quality of the bike. Everyone I have spoken to in person has downplayed the importance and suggested that the dereilleurs should be the last thing to replace as they least affect the ride quality. The reason I ask is that on my mixte (which, at this point, has about 89% new components) I want to be sure that I am not going to have the ride quality sabotauged by crappy components. My front and rear dereilleurs (Suntour) are in decent condition, but the front one has giant gashes in the metal (presumable from the chain getting tangled in it or something, I'm guessing)? I've commented on it several times to various mechnics and so far, they've all indicated that it won't have any effect on function.
The reason I want to ask here (and why I might be somewhat suspicious of what the mechanics are telling me) is that I've had an extremely difficult time communicating that I am not building this bike for a commuter or daily beater. I want it to be reliable, and I want to feel comfortable taking it on longer rides where there may not be repair facilities and, secondly, I want the components to be new enough to be easily servicable so that there are parts available if I have to stop at a random bike shop for repairs. Yet, somehow, the concept of wanting these features on a vintage bike, especially a mixte, seems to escape the sensibilities of pretty much every single mechanic I've talked to. So I'm taking it here because I feel like you all may sympathise a bit more with these preferences. :)
It would have to be very exotic indeed. Shifters are indexed; derailleurs are not.
ReplyDeleteI went with Rivendell's recommendation... 48x36 compact double and 11-32 8-speed cassette on my AHH... Couldn't be happier...
ReplyDeletein the old days we used to just stick a screw driver between the cage and bend out that fussy outer cage. ah, those were the days;-)
ReplyDeleteIf you're going to stick with a "triple" FD, I'd be hesitant about a road derailer. Many are intended for 52 or 53 tooth large rings. The Tiagra triple FD is better suited for 48-ish large rings. I'm not sure where the 105 slots into this. But if you decide to go with a double, losing the outer ring, a "mountain" front derailer may be a better fit (if you can find one that doesn't look wretched).
ReplyDeleteVelouria,
ReplyDeleteIf you look at the Haris Cyclery website they have the Specialties TA Cyclotouriste Cranks for sale.You can get the rings 42,44 and 46 and the inner rings in 26,28 and 30.These are great cranks.Well worth the money!
Also,have you taken a look on Sheldon Brown's Bicycle Pages at the Rivendell Rambouillet? It has a front chainring that is 42 teeth and a single.The back has a mega range 11-34 cluster.
I am fortunate enough to be the current owner of this bike and love the set up. I often found myself in only the middle ring of a triple set up and wondered what something like this would be like. It works really well.I had often thought about setting up a bike this way but didn't want to go through everything necessary to change one of my current bikes.When this bike came up for sale I wasn't even paying attention to the gearing set up.It came as a pleasant suprise.Sheldon, as always, was many steps ahead of me and my thinking. I imaging that you could go even smaller than 42 up front and be able to climb just about anything.
Another company you might be interested in is White Industries.They make a variable bolt circle diameter crank set which can go down to 24 teeth.
At the moment three of my bicycles are set up as compact doubles. I had many of the same issues with the triples that you have, decided to give it a try and now have it on the three bikes and I love it. Truth be told mine are the vintage TA and Stronglight cranks but they are not too terribly hard to aquire.I personally think that the TA's are easiest to find and have the widest selection of chainrings.My set up is 46/27 up front. I run a vintage Campagnolo Rally derailleur in the rear but any good touring wide range derailleur will do.I am sold on the double set up.
I'm no gearing expert, so somebody else would have to do the math, but SRAM's APEX group, has an 11-32 rear cassette and if you pair that with the a 48-34 compact double crankset you'd get a range that's probably better than what you'd get from most triples. I've never used it, but theoretically it's an interesting choice. Definitely not the cheapest one. Here's a review with much more specifics... http://bicycling.com/blogs/thisjustin/2010/02/18/srams-new-road-group-apex/
ReplyDeleteThe White industries Variable Bolt Circle crankset is a good double crankset, you can choose the number of teeth you want for each chain-ring when you purchase it. I have one for my mountain bike but have yet to install it...You can run a double with a 24 tooth inner ring. Maybe you should try a 42 tooth big ring.
ReplyDeletehttp://www.whiteind.com/cranks/roadcranks.html
I meant FSA when I said IRD in my previous comment. Mea culpa. (That's Latin for "my bad.")
ReplyDeleteFor the record, there have been indexed rear derailleurs. In the 1930's, Cyclo of England made one that had indents much like what one finds on a three-speed trigger control. That meant, of course, that it could be used only with the shifter Cyclo made for it. In the mid- and late-1970's, Shimano did something similar with Positron, which was used mainly on lower-priced bikes.
ReplyDeleteTo my knowledge (which is not as great as that of the late, great Sheldon), those are the only two indexed derailleurs ever made.
I think the confusion re: indexed derailer was that someone didn't know that IRD is a company.
ReplyDeleteSort of like that joke when someone comes in to a shop and says they want an IGH hub, please. Which one? IGH, please. Yes, but which one? :)
Having said all this, I should probably remark for the benefit of humanity in general, that some older derailers don't work entirely well with indexed, so it's not entirely true that any derailer is ready-to-go for modern shifting.
Spindizzy--the front cage is set up as bestest as it's inhumanely possible to do so, including the slight angle you mention. The rubbing is caused by the grotesquely formed innards of the cage. That thing looks like it will rub regardless of what we do.
Some people wondered about chain length and B-screw adjustment and all that nonsense, but the mechanic who put this thing together isn't a slouch, and I did go over things once or twice too when we first started having troubles, verifying that nothing was amiss. The cables are fine, too. It's just a crappy RD + crappy FD + inherent fussiness of the triple.
It is a bit hard to tell from the photo, but I wonder WHICH Shimano Sora FD you have -- they make one optimized for a double (FD3400) and one for a triple (FD3403). The triple one has a different shape. It is also a bit hard to tell from the photo, but it looks like it might be mounted a tiny bit high -- there should only be a few mm between the outer cage bottom and the large chainring.
ReplyDeleteAlso, while the Sora triple is a decent FD, there are different cage profiles and shapes out there -- and there used to be far more options in good road triple FDs -- that's why I recommended getting the bike to a good older mechanic -- one who has a good experience of triple and touring bikes going back to at least the 1980s. It should not be hard for a competent mechanic to set up the bike properly so minimal trimming is necessary.
Justine beat me to it, I was going to post this http://breakingchainstakinglanes.wordpress.com/2011/02/01/positron-ic/ in reference to "indexed derailleurs".
ReplyDeleteYeah, if you can think of it, somebody's probably already tried to put it on a bike.
I can say with some confidence that your front derailleur performance will be BETTER with a different front derailleur, but I can't tell you if it'll be perfect.
What it comes down to is that this is probably a question that is better answered by a good local bike mechanic who has the bike in front him than by a bunch of strangers - friendly and helpful as they may be - over the internet.
Is your Sora FD made for a triple or a double? If double, it may have a narrower cage. I know that Soras were made for both types of cranksets.
ReplyDeleteIt hurts my head too. It depends what your rear cassette range is plus the front chainrings. The Velo orange gran cru double chain ring that is vintage style has a huge large chainring and a very small chainring. Sold out too! According to my husband that's the PERFECT chain ring set to replace a triple crank. This crank would be perfect for touring, randoneering, getting up hills AND going hard and fast. For many double cranks it's either too high or too low. I am wanting less gears with the same range and have been looking at vintage 5 speed freewheels with huge range. For me the headache ensues when I try to think about having great granny gears with road components.
ReplyDeleteSo please VO, order some more of those cranks!
The deore components are meant for mountain biking but have been put on touring bikes of all levels for some time. While the deore might accommodate hills, it isn't necessarily what you want on a road bike. My husband has a touring bike with 105 road components and it goes like a road bike, while my touring bike has deore and rides like a mountain bike-which is fine for some applications like chugging up a steep dirt trail.
How does the Sam hillborne with deore components compare to your bianchi with road components(aside from obvious wheel, frame size and bianchiness differences)?
Just want to say that I've been away all day and have not read the latest comments. Thanks everybody for contributing, though I am genuinely shocked at the number of comments. I thought this would be a boring sleepy-Saturday post...
ReplyDeleteShimano is compelled to put larger and larger balloon animals on the inside of the cage every year to speed shifting by .001 sec.
ReplyDeletere: screwdriver. Done it. Please send POS Sora to me after replacing. I'll flatten it in a vice or on an anvil and send it back. Guaranteed to be a different shape.
Or I'll just send you my entire cargo bike drivetrain that works. Need to turn it into a fixie anyway.
Oy. Reading the comments I am feeling uneasy that Harris is blamed for the Sora FD. They did not spec my bike, I did. When it came to derailleurs I did not know what to choose at the time, so I consulted someone or something... don't remember whether it was someone at Harris or someone at Rivendell, or maybe I just looked at one of Riv's "typical builds" lists. Anyhow, I no longer remember how the front derailleur was chosen, but it was not necessarily based on Harris's recommendation (which in itself could mean, like one of 4 different mechanics).
ReplyDeleteInterestingly Riv's typical build includes a Campy FD: http://www.rivbike.com/assets/payloads/321/original_435326_Rivendell.pdf
ReplyDeleteIn their world of Nitto this, Sugino that it's the only Campy part I remember them selling. Odd, but tells you they know something.
somervillain - It's a triple.
ReplyDeleteJim - That is a fairly new typical build example; pretty sure the samples they had on there a year ago had different components. In fact I don't think they even sold that part last year, though I could be wrong.
Looking at my fancy carbon Campy Chorus compact double FD the shape of the cage is pretty much exactly the same, as far as I can tell: http://www.rivbike.com/products/show/campy-double-front-derailer/17-137
ReplyDeleteMy takeaway? Flat sides and wide cage are good. No balloon animals.
In the dark days of the 70s some high speed mechanics would cut the inner side of the cage off at the bottom and attach an offset section(often made from another cage) to make the cage wider at the bottom to make a "Triple" front derailleur.
ReplyDeleteI have an old Campy Valentino modified thusly somewhere. It's likely only an inch or two above floor level in the great geological formation of bicycle sediment in my basement. If you know about what time period the part you need is from I can tell you how deep to dig. Late 90s MTB disc hubs or anything crabon, scrape around at the top, mid 80s bolt on aero bar extensions? Halfway down, look for anything turquoise or purple, it'll be in there somewhere. Anything Mafac, Zeus or Galli, or the really neat vintage BMX stuff? Hmmm, bring a shovel (and pack a lunch).
Spindizzy
There is not a damn thing that is inherently wrong with a triple. By the description given of your problem, there is clearly something wrong with your set up. Again, check the cables, chain length, derailleur hanger and barrel adjustments (and no I didn't mean the b-screw; I assumed that was okay, you never mentioned the derailleur striking the cog)
ReplyDeleteI would also add there is not a damn thing inherently wrong with well-adjusted Sora or Deore derailleurs. If anything manufacturers tend to give slightly better value to the pound in their lower range components as a sort of come-on for upgrades later. They want you to like your intro, and desire grander things for yourself- lighter, faster - further own the track.
ReplyDeleteWith derailleurs what you tend to get as you move further up the ladder is lighter weight and possibly (although this is debatable) better durability; not really that much better performance, or at least only incrementally so. Derailleurs are pretty simple pieces of equipment really, designed to do a simple job. They are the least interesting upgrade you can do on a bike.
By all means re-figure your drivetrain if you've a mind to do so and want to spend the money, but if your heart really isn't in it, a few fundamental checks on cable, overall adjustments and chain length and the like - going over your set up closely in other words, with a censorious eye - can save you quids.
I am currently riding a TA double - 46/30, with Campagnolo 10 speed 13-26. shifts perfectly and I use a short cage Campagnolo centaur rear derailleur. The front derailleur is a Campagnolo Super Record from the early 1980s.
ReplyDeleteMy new frame will be set up the same way. I found switching to the double was a great decision. Cut out the middleman.
The friction shifting will fix your problem. It works a treat on my salsa fargo...
ReplyDelete"Another positive of the retro “friction” shift is that the way that the mid – derailleur moves….in that you can manually position it rather than the typical “clunk” into place. Why is this good? Well it allows the full range of gears without the front end rubbing! If you hear a bit of chain rub….then adjust it slightly. Fixed….hoorah!"
http://www.robotoranges.com/2009/06/20/salsa-fargo-first-impressions/
I have a Sam Hillborne that I had the folks at Rivendell build for me. (I live close enough to have ridden the bike home - wonderful maiden voyage over the Berkeley Hills.) I chose to go with a 3x8 setup (46/36/24 x 11-32) over a 2x9 that could have very similar overall range because my understanding is that the 8 speed chain is slightly more reliable and that fewer gears in the rear will always be less finicky.
ReplyDeleteTo sum up, I have Riv's standard Campy Mirage derailer in front, and I have had zero problems with it. When shifting from the highest to the lowest gears in the rear it does require trimming, but that is the nature of derailers in general. By not running brifters, I don't have to use front indexing (one of the most unnecessary "innovations" of all time IMHO) and can actually trim the front using my brain, instead making constant adjustments to the front indexing itself.
I do find that I spend the vast majority of the time in my middle (36t) chainring and could easily live without the 46t, but why get rid of it if it is there as an option? I could ALMOST get away without the granny but the Northern California hills and my propensity to carry heavy loads make me grateful it's there when I need it.
I write all this to suggest the following: is it the fact that you have to trim the derailer at all that you don't like, or are you finding it impossible to find any position that works? If so, the cheapest and simplest thing to try is to replace the front derailer. You could always replace your biggest front ring with a guard instead, but why?
As for the skipping in back, I'm guessing that it is almost certainly unrelated. I just don't see why you'd spend all the money to replace the entire drivetrain when a new FD and a properly adjusted RD might solve the problem. The folks at Harris just might be able to do a better job than the Co-Habitant when it comes to setup and adjustment. I'm a bit of a hack mechanic myself - I'll never get stranded on a ride or tour but the pros always seem to do a better job with fine adjustment issues. They just plain have more experience. No offense intended to the C-H.
One more point: you might not even need a new front derailer at all, just a professional to adjust it better. It is possible, however, that since the Sora was designed with indexing in mind, that it has a relatively narrow cage and therefore not much room for error when trimming. I'm not sure if the Campy is any wider but I just thought it would be a useful point of information that I'm running it without any problems. It does require trimming when the rear goes from one extreme to the other, but I would imagine that a double would as well.
ReplyDeleteDaniel: once more, it was the "folks at Harris" that put this bike together.
ReplyDeleteMDI: got it. I guess what I'm trying to get at is, if I were to remove my big ring and my granny and just run a 1x8, I'd STILL have to trim my front derailer, so switching to a 2x in front is not necessarily going to solve a trim problem. If other front derailers have a wider cage, that certainly might help, but simply upgrading to a more expensive Shimano is not necessarily going to fix anything. If Harris built it, I would hope they would help you solve the problem in a manner that is less extreme than replacing the entire drivetrain.
ReplyDeleteIt's actually not unusual to have a double that you don't have to trim through 8 or 7 out of 8 gears in the rear. We have one, somervillain just built one and lots of people have doubles like that. There's something to be said about not worrying about trimming your front after nearly any rear shift.
ReplyDeleteOf course longer chainstays help with that, too.
ReplyDeleteif it was me i would ditch the big ring, 36 x 11 still gives you an 86" highest gear which is plenty high enough for randonneur purposes (allows 25mph at 90rpm) You could replace the big ring with a chainguard or just change the chainring bolts. You might want to change to a slightly longer BB axle to get the centre-line of the two chainrings in line with the centre line of the cassette. nothing wrong with Sora level equipment, its better than far more expensive stuff from thirty years ago, and theres hardly any difference between front derailleurs nowadays anyway. make sure you have the right type for double or triple though. also i always set my chainlength so that the rear derailleur is at maximum stretch when on big chainring and second biggest sprocket. it is then physically impossible to use the big/big combo which shouldn't be used anyway unless you are running a 5-speed block, and you get a nice short chain with minimum chainslap.
ReplyDeletei run a double on two bicycles, but hated it at first. i am not embarrassed to say that H made me do it and i know nothing about picking these out or the complete logic of it all, but he does and INSISTED i would have two. :) if you have any questions ~ perhaps he can offer guidance. it can be a little difficult on big hills for me at the beginning of the season, but then in a few weeks i think nothing of it. go for it!
ReplyDeleteWRT double without trimming - I thought my front shifter was indexed for 18 years. It turned out it was just set up well (the limit screws and angle I think). It is a 52/40 with a 13/26 7 speed "racing" bike with relatively short chainstay. I cross chained to my hearts content (from the smaller chainring, which I never left unless going down a straight hill). I am now discovering the joy of trimming with the triple that i have just installed (have to get up the hills with a trailor somehow...). I would be very tempted to go wide double. I suspect (with no real knowledge) that you would need to go to a double derailleur and real double cranks to get the desired effect of not having to trim.
ReplyDeleteMatt K
The comments above are complicated and replete with terrifying misinformation and excellent advice, alike. I'm not going to try to put anyone on blast, but Justine and her ppl offer the best advice and the accurate skinny on things. I just wish to offer some facts/concepts that might actually help the situation out:
ReplyDelete- 6-bolt chainrings are super-dead, and the only reason to buy a fake-french outmoded crankset is so you can look fake-french and fashionably outmoded as you pedal around the earth. The only real benefit is a fairly narrow q-factor, but that doesn't seem to be the problem, here. The XD cranks on the bike now can be run as a triple, or as a double in two different configurations. Harris offers the 110mm bcd rings in sizes ranging from 33 to 54 in 1-tooth increments, and the 74mm bcd inner rings in sizes ranging from 24 to 36 in 2-tooth increments. The only ppl offering 6-bolt 50.4mm bcd chainrings are purveyors of NOS and used goods on fee-bay and weird specialty shops, and these folks will no-doubt charge exorbitant prices. Harris has 'em in 26t, 28t, and 30t inners as well as 42t, 44t, and 46t outers at $90 a set! Even the fake-frenchmen in Maryland have no 6-bolt rings on-offer at this time. Let's move on; embrace the wonderful 110/74bcd cranks. They may have some flaws, but they are extremely versatile.
-if you're using Sheldon's gear calculator, you might have to bust out a traditional calculator to find a mathematically comparable wheel/tire size if you're running an "alt" format wheel. If you're running 650x42b, use the calculator's setting for the 700x23c. (For 650x42b, consider that 584/2=292. 292+42=334. For a comparable 700c size, consider that 622/2=311. 311+23=334. Hence, in terms of gear-inches and gain-ratios, 650x42b is roughly equivalent to 700x23c.) Of course, it won't be the same on a wide, cushy tire versus a skinny, hard tire, but the calculator does not take that into account. If you are revising your drivetrain, it is highly recommended that you do the math to get your desired range and steps.
-Shimano Sora front derailers are awesome. Their only sins are ugliness and heaviness. "Ugly" is a subjective type of thing, and "heavy" is something your Riv should be well-acquainted with. They'll work fine with your system, unless you have a realllllly wide bb spindle, in which case you might want to try a mtb-group derived "trekking" FD, that will accept a 48t large ring. If trim is an issue, as it ever will be on a friction system, you might prefer to "downgrade" to an ancient, early-80s front derailer, as these were designed to work with fatter chains. Incidentally, trimming the front is part of friction shifting, but at least you can trim effectively. Indexed front shifting often requires trim, but some indexed front shifters do not allow for *any* trim, or only for a very limited and finite trim setting.
In closing, Deore RDs are awesome, with sins similar to the Sora FD. Additionally, some feel that they do not index as precisely as their pricier brethren. Moot point, here. If your deore is ghosting, you might want to look at all of the factors folks have mentioned above (chain length, any damage/wear to the spring, slipping shifters, etc) and you might also want to make sure your pulleys are clean, not overly worn, and spinning well. When i first started riding, i over-lubed my chain, and the amount of mung that accumulated on the pulleys caused irksome ghost-shifting.
I sincerely hope this helps,
-rob