5-Speed Conversion!

My conversion of the Mercier mixte to a 5-speed is pretty much complete, and it worked out nicely. I've received some questions about the process since I first mentioned my plan to do this, so I include answers to these questions here.

What is a 5-Speed Conversion?
A 5-speed conversion refers to transforming a vintage 10-speed bicycle into a 5-speed by removing one of the two front chainrings and the front derailleur system (see before and after pictures above). In the end, the bicycle is left with a much simpler set-up of 5 chainrings in the rear, 1 chainring in the front, and a single gear shifter. It works much the same as a 5-speed hub, only the gears are visible rather than hidden inside the hub.

Why do this? Doesn't it mean you have fewer speeds now?
Hard question to answer, but I will try: The advantage of a derailleur over an internal hub, is that it allows for much wider spaced gearing. Riding the Mercier around hilly areas, I can get by perfectly well with just the middle 3 rear gears. The 2 extra rear chainrings provide a nice "just in case" buffer of one higher and one lower gear than I'd ever need, but the second front ring (which provides 5 additional speeds) and the whole front derailleur system (which switches between the two front rings) are useless entirely in the context of where and how I plan to ride this bike. Given my certainty of this, converting it to a 5-speed made sense, because it would simplify the handling of the bicycle and it would get rid of extraneous components. Also, this bike (as many older French bicycles) was originally designed to have a rear-only derailleur system. This is evident, because it has a braze-on (on the downtube) for just a single gear shifter. So converting it to a 5-speed reverts to a traditional design.

If you're going to make it a 5-speed, why not use a 5-speed hub and ditch the derailleur system all together?
The main reason, is that no existing 5-speed hub could give me the same customised, wide spacing as a 5-speed rear derailleur. It's not just about how many speeds you have, but how useful each of those speeds are. Additionally, it would cost a ton of money to rebuild the rear wheel with a 5-speed hub, whereas the 5-speed derailleur conversion was inexpensive. And finally, I am trying to keep this bicycle fitted with traditional components, and French bicycles were traditionally fitted with derailleurs.

How was the conversion done?
Keeping in mind that the process will differ depending on your current set-up, here is what generally needs to be done, step-by-step:

1. Front chainring removal
Since you will only have one chainring in the front now, you need to figure out how to get rid of the second one. The main issue here has to do with how the crank arm is attached to the ring(s). On some bicycles, it is possible to simply remove the extraneous chainring and the remaining chainring will hold up the crank. On my Mercier, the two rings are a unit, attached to the crank via a proprietary bolt system. To make a long story short, we could not simply remove the extra ring. Rather than get an entire new chainring and crank system, it occured to me that perhaps the teeth on the bigger chainring could be filed off - turning the ring into a chainguard. I discussed the idea with metalworker and bicycle mechanic Jon Gehman, who is a reader of this blog, and he agreed that this was a good way to go. I then sent him the chainring for a "de-toothing" service, and he did a spectacular job.

Here is a close-up of what was formerly the larger chainring. Notice how beautifully the edge is done - giving it a professionally finished look.

2. Front derailleur removal
This was the easiest part. The Simplex front derailleur simply unbolts and removes. On the picture above you can see that the rainbow decal is a little worn where it used to be, but that is all.

3. Changing the shifters
The ease or difficulty of this step depends entirely on what sort of shifters you have to begin with. If your bicycle has separate (unconnected) shifters for the rear and front derailleurs, then you simply remove the one that controls the front and you are done. If your shifters are a unit, then you will have to remove them and install a single shifter instead. Above is a vintage Huret single shifter for mounting on the stem that I bought for this purpose. It's beautiful, "period-correct", and can be bought fairly inexpensively. The Co-Habitant installed the shifter and connected the cable to the derailleur.

Here is the Huret shifter installed on the stem. I am not 100% sure though that this is the ultimate solution. Originally, the Mercier had downtube shifters, and this is where the single braze-on is located. However, I do not understand how one is supposed to use downtube shifters on a near-upright bicycle. At least for me, and in traffic, they were too much to handle - especially given that the shifting has to be done with the right hand.

So now there is a cable stopper where the downtube braze-on is, and the cable then extends further to the stem. Though the Huret shifter is beautiful on its own, I am not sure how fitting it is here. For instance, the reason it is not all the way at the bottom of the stem, is that placing it here makes it hit the handlebar when it is moved all the way forward. Hmm, right? Your thoughts on this welcome.

Overall I am thrilled with the 5-speed conversion. The Mercier is light, easier than ever to handle, and now ready for its fate as Studio Bike. I admit that I am reluctant to send it over to the Studio and quite like having it here at home. But I also look forward to exploring a new neighborhood together... and to having less bike clutter in our apartment!


  1. i can see now how this shifter was designed for a stem with a longer reach (distance between quill and handlebar clamp). it seems that the short stem results in the shifter touching the handlebar when positioned farther down the stem.

    hmm... you could always adjust it so that you don't have to move the lever all the way forward to shift into the lowest cog.

  2. Wow, that looks like it went over beautifully! I actually thought the larger front chainring was a chainguard that you had added, and had to go back and look again when you mentioned you left it on and just filed the teeth off. Whoever it was that did it did indeed do a beautiful job.

    I hope you can figure out the shifter issue to make it workable and comfortable for you.


  3. somervillain - We considered that, but it would mean that the lever would be pointing towards the rider most of the time, which seems unsafe in the sense of posing an impalement risk if I happen to crash...

    Thanks portlandize, the chainring-to-chainguard conversion is indeed a work of art and looks beyond what I was expecting.

  4. A wonderful explanation, aided by pictures, of the conversion process. As a relative newbie to the world of bikes, I wish more explanations of bike-related matters were as clear as this one.

  5. Very cool post. What kind of tool or machine is used to de-tooth the wheel?
    You seem to always think of more topics to post. I don't know how you manage to keep your blog so fresh and interesting...
    Keep it up. Thanks

  6. AHH, Lovely, quirky French goodies for a charming old french becane.

    There is a chance that your shifter can be made to work better without modifying it. If you remove the screw holding the shifter onto the mounting band and slide the lever and the various washers and spacers off the post that it all rotates on, you MIGHT find that there are multiple positions that this assembly can be mounted in. If that is the case than just rotate everything one position anti-clockwise and re-assemble. If you don't find this fortunate state of affairs there are other options. The bottom metal arm(lowgear lever stop) that limits how far the lever can rotate down can have material removed from it allowing greater travel. It would not require many additional degrees of travel to gain a usefull amount of additional cable take-up. You would end up having the handlebar act as the highgear stop instead of the other existing metal arm and it would require a little trial and error on the part of the mech. who sets it up the first time but it would allow that shifter to be mounted lower on the stem. Maybe all the way down.

    There are nice benefits to a long shift lever on a non-index shift bike, it requires less effort to move the lever which allows a little more friction in the system, which is good(within reason) on a system that requires friction to hold the derailleur in position. The other benefit is that for the same amount of cable travel, the lever moves a greater distance at the end where your hand grasps it making the sweet spot where the gear is properly engaged a bigger target, If you ever noticed that many of the old Schwinn 10speeds had long levers and wondered why, that was part of it. It was easier for people to find the gear when they didn't have to fiddle around moving a stubby lever around in tiny increments. I think Schwinn also liked long levers because it appealled to their desire to use the heaviest possible componant at every opportunity.
    There is one more option to modify the shifter that would allow you to choose the lever position and be able to set-up and adjust the derailleurs in the conventional way, but it is not out-patiant surgery and requires just the tiniest bit of welding.

    This bike of yours just gets sexier all the time. When I see pictures of it I start to have this fantasy with a Django Rhienhardt/Edith Piaff soundtrack and imagine the smell of great French cooking and quiet rides down charming Parisien streets with someone I have no business being with... Then some Renault dang near kills me at an intersection and I get in a shouting match with the driver and the Gendarmes turn up and it all goes to hell...

  7. Can a one speed be converted to a three speed?

  8. Also, do you have an online address of where to get dress guards?

  9. Another advantage of the dérailleur is that it is both lighter and more efficient. What's more, you can always adapt to new conditions with a different rear cluster, or add a sixth gear if needed.

  10. Mon Dieu! How can Sr. Helga ask such a thing!! While the single to 3speed conversion is, how you say,"childs play", it is an affront to everything French!!! Have you seen a FRENCH 3 speed hub mon ami? I think NON! That particular endeavour requires the filthy english(small "e") Sturmey Archer contraption or the regrettably japanese Shimano item known the world over as the "tin can"(the"tin can.How revolting) Let us not even discover ourselves considering the overbearingly preposterous teutonic article deviously sold under the honorable FRENCH name Sachs... Why abandon the acme of mechanical perfection, THE DERAILLEUR!!!! Even the spelling of which is making me to tip my beret to the beloved Tri-Color!!! Did DeGaulle ride the excreble "3 speed"? Or Flobert, Camus, Marcel Marceu (admittedly his machine was invisible but we may be CERTAIN it was not so equipped)?! Of course not! It is not too late!!! You must abandon this fools quest immediately and submit at once to the gentle seduction of the DERAILLEUR!!!!

    I am finished.

  11. Sr. Helga - To convert a single speed to a 3-speed you will need to rebuild the wheel around a 3-speed hub. This process has nothing in common with what I described here, since the derailleur is not involved.

  12. spindizzy, thank you. i haven't laughed so hard in ages.

  13. spindizzy - Yes, thanks indeed : ) And if it makes you feel better, I often wear a beret when out riding my mixte after a breakfast of omelette and brie.

  14. mmmm, I couldn't laugh because I didn't understand a single word spindizzy said.... However, I found out what a derailleur is.

    Do you mean to tell me that single speed bikes are French?

    I'm wanting to learn more about bikes...

  15. I have seen French three-speeds. However, they had either Sturmey-Archer or Sachs rear hubs. The former est anglais, and the latter is German. (Ironically, during the 1980's, Sachs would acquire several major French component manufacturers such as Huret and Maillard.) So, yes, there is something juste about a derailleur on a French bike. Also, as Steve pointed out, the system is ligher and more efficient, and allows for a greater range of gear choices.

  16. What you've done is, in a way, similar to what I'm going to do with the Miss Mercian I'm building. It will have a single chainring in the front and an 8-speed cassette in the rear.

    However, my chainguard will be different from yours? Remember that chainguard with the floral cutouts you showed on an earlier post? I've just acquired one of those, and it's going on the Miss Mercian. And it will have fenders, porteur handlebars, stem, seatpost and "retro" water bottle cage from Velo Orange.

    All I need now is the frame! That's expected in mid- to-late July.

  17. Justine, I can't wait to see your frame, and I am curious what you think of that chainguard (quality-wise, and how easy it is to install). I will be getting a proper French-style chainguard for this bicycle in addition to the outer ring. More on that later : )

  18. That chainring looks fabulous, utterly natural.
    I was wracking my brain for a moment trying to figure out how he did it.
    (I think I know. I'm starting to "get" machining.)

    La Belle Mercian is getting cooler and cooler with each step. I'm sure it's without trepidation-she knows she's going to get a ride in at least weekly, even if it's just going out for Cafe Au Lait.

    Et Spindizzy, Vous êtes un raie de gaieté et émerveillement. Sacre Bleu!

    Corey K

  19. I don't know what came over me, sometimes I get lightheaded after too much boullabaise and wake up wearing clogs and a striped jersey with an accordian in my lap.

    I think that the best way to remove sprocket teeth is to carefully cut them off with a hacksaw or bandsaw (using a 32tooth per inch blade) and not cutting too close to the bottom of the valley between the teeth, Next, using a benchmounted disc or belt sander and laying the chainwheel flat on the sanders shelf, sand the remains of the teeth down to the point where the valley just dissapears, then using a VERY light touch ,keep the chainwheel flat on the shelf and gently touch the edge along the sanding belt or disc and sort of roll it along,don't use any pressure and keep it moving. If you are making more than a few sparks at this point you a using too much pressure. You are only trying to remove a bazillionth of an inch at a time. After a few(or a bunch)times around the ring you should have a nice smooth, round edge. I like to finish the edge with a good mill file so that there are no tool marks and if it is steel I recommend some wax or paint to keep it from rusting.
    Aluminum chainrings are the easiest to do because they are so soft but they are also the easiest to screw up for the same reason. If you have a hacksaw and a good file you dont need the powertools but you will need ALOT of time. If anyone wants this done I will cheerfully do it for them for the cost of a John Coltrane C.D. or two, see the photos above for an example of my work(dang, now my secret identity is revealed and I'm going to have to behave myself on this blog...).

  20. Msr. Corey, do not be speaking your absurd foriegn languages to me, mon ami. The French language she is an encumbrance to all, including the french... The illusion of fluency is of sufficiency for me...

  21. Interesting upgrades!

    I just had my 5-speed mixte changed from a downtube shifter to a thumb shifter, and it's made a huge difference for me. Maybe I should get around to posting the pics...

    Sr. Helga: while I can't say I'm as well versed in bike knowledge as some of the previous posters, there are often French 3-speeds made with derailleurs. (They LOVE a derailleur.) You can see them posted on ebay.fr or http://www.velo-vintage.com/ if nowhere else.


  22. To Sr. Helga and anyone else who wants a three speed:

    The best way to get a three-speed is to find an old bike (e.g., Raleigh) that is already a three-speed and to make sure the gears work. I would convert a derailleur or single-speed to an internally-geared three-speed only with an older (up to the early 1970's or thereabouts) Sturmey Archer hub. Quality on the later ones declined precipitously because SA never replaced or retooled their machinery. It was so bad that when SunRace bought SA about ten years ago, they found that they had to scrap nearly all of the physical equipment.

    I don't recommend the Shimano three-speed hubs. (I'm not anti-Shimano, so this isn't a screed.) I have had two of their three-speed hubs, and neither lasted me more than a year of commuting. And, when I did ride them, I was breaking spokes about every 100 miles or so. Someone who knows about these things tells me that the reason I and others have broken a lot of spokes on the Shimano three-speeds is that the flanges are very thin.

    I have no expereince with the Sachs three-speed. But from what I hear, they're not as good as the older SAs.

    Anyway, Velouria, I really like your chainguard.

  23. "Gear-hubs with a large number of speeds (Rohloff SPEEDHUB excluded) are generally less efficient than a properly lubricated and adjusted derailleur system in new condition. Less sophisticated gear-hubs such as the 3-speed hub (with only a single epicyclic stage per high/low gear, and direct drive in second gear), when run-in and properly lubricated, are however able to match the efficiency of similar quality derailleur systems, because the chain is properly aligned and does not run through jockey wheels of a chain tensioner. In real-world conditions, derailleur gears are much more likely to suffer inefficiency due to poor lubrication, extreme wear, excess dirt or inaccurate adjustment."
    Although the derailleur is indeed lighter and matches this type of bike better, I don't think it is more efficient. Also, a new SRAM or Sturmey archer 5 speed hub will have the same range of a 12-28 cassette, so there isnt't any considerable difference in range either. It is a matter of lightweight and historical matching vs simplicity and maintenance free option.

  24. My Pashley's 5-speed SA hub has amazing range. You can't get started in 5th and you probably couldn't exceed 7-8mph in 1st.

    It's true that my Motobecane has derailleur gears, but I much prefer the IGH setup. So much so, that I considered getting a light road frame with track drop-outs and installing the spare 5-speed SA hub that we have from Velouria's Pashley conversion.

  25. Justine, innnnteresting.

    Do you remember whether your Shimano hubs were 333 or 3s? I've heard awful things about the 333, but I use a 3s and I like it for its smooth shifting.

    I've also broken a few spokes on my rear wheel, although I never thought it might have something to do with the hub. I just assumed that the wheel was low quality and lost spoke tension over time.

  26. Love the conversion to 5-speed!
    I just got done cleaning/polishing the Huret double stem shifters on my wife's 1975 Raleigh Sprite and they look great. I was considering replacing the front derailleur, also Huret, because the cage had completely worn thrnough from chain rub. Fortunately, I scored a NOS Huret cage on ebay. Don't know how I'd survive without it.

  27. Well done and gorgeous as usual. I love the concept of using the large outer ring for a guard. I may have a candidate...

    @Sr. Helga; I purchase skirt guards from Morgan Imports in NC (look down near the bottom of the page).

    Of minor grammatical interest the word "derailleur" means to derail and was used quite often in the context of train wrecks...how civilized is THAT?


  28. Nice ride!

    I see your Huret shifter is in good condition. Unfortunately, mine is not so good. The pin that goes through the outside cap (over the bolt) has broken. Do you have any insight as to how this could be replaced or fixed? Might you know what an unbroken pin looks like or how it is installed?


  29. Herzog: The first one I had was a 333 that came with a Miyata three-speed. The second was a Nexus three-speed that came with a Breezer. I no longer have either bike or hub.

  30. This is great! Any chance this conversion could work in reverse? For example, I have a 3 speed cruiser that I'm hoping to convert to a 5 or 10 speed to give me more speed so that I can use it as a commuter. Thoughts on whether this is feasible and what I'd need to do? I'm a complete bike newbie.




  33. I realize that this a year old, but if anyone's interested, on a recent trip to France we saw a LOT of French city bikes, mostly mixtes but not all, with 3 speeds - with derailleurs! The French bike manufacturers only wanted 3 gears on their city bikes but couldn't bring themselves to use S-A hubs?!

  34. My guess for the way that the teeth were removed on the outer chain ring is by use of a lathe. Simply turn the outer surface smooth. I assume that a professional metal worker has a lathe and the knowledge needed.

  35. WRT the single stem-mounted shifter, and (what I take to be your dilemma with asymmetry): I've seen a number of "single stem-mounted shifters" (always on the right-hand side), with a complementary bell on the left-hand side. It seems fitting, given one's willingness to shift with the right hand, that one's left hand might also play a roll. (ring a roll? play a ring? ring a bell!)

    1. My son just converted my 1972 Peugeot mixte to a 5-speed and mentioned that I could place a bell where the front shifter used to be. It wasn't clear how we could do that, or what type of bell works. Do you have any suggestions, directions?

  36. Nice to see someone else championing 5 speed conversions. I impulse bought a customised cro-mo vintage racer a few months ago for next to nothing only to discover it was a 5 speed when I got it home (but still had the front derailleur attached). After removing the FD, it only took a couple of rides for me to realise that this sort of 5 speed set up is absolutely brilliant and was perfect for the city, I also love how it looks. I'm a total convert to the idea now and I'm about to customise my newest bike in the same way.

  37. I've often considered a 10-speed to be unnecessarily complicated. My old Dawes Galaxy tourer had ten speeds, but I've now got it in pieces pending a complete rebuild, and I plan to build it up as a 5-speed, with a single chainset I salvaged from an old shopper bike. Curiously, despite the shopper being fitted with a wide chain, the chainring has narrow teeth suitable for a derailleur chain. Maybe it was swapped at some point. It's cottered, but at least it'll give it the vintage look, in keeping with most of the other components. Five speeds should be more than adequate.

  38. Hello, thanks for this post and comments! Did you have to replace the chain with a shorter chain after the conversion? I'm in the process of converting my Fuji 10 speed to a 5 speed and need to replace the old chain. I'm not sure if I should get a 10 speed chain or a 5 speed chain. Appreciate any advice you may have on that. Thanks!

  39. That chainring work is so gorgeous. A couple of years ago, I converted a 1980 Fuji Gran Tourer to a fixie. For gear ratio and chainline, I am using the smaller chainring. The large 52 tooth chainring bite my eye all the time. Thanks for the nice idea here. I have a bench grinder so I am thinking to draw a circle on the large chainring and then slowing grind off these 52 teeth.

  40. I've been looking at converting my 21 speed bike down to 1x7, and all the videos and such I've seen specify that you need something on the inside and outside of the chain ring to keep the chain from bouncing off...your chainring converted chain guard works for the outside, but do you anticipate needing anything on the inside? Why or why not? It would be so much ease for my project r if I don't end up having to do that.


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