Planning a Wheelbuild: Hypothetical Practicalities
After my earlier post on wheelbuilding, many expressed an interest in the concrete details of the process: specifically the costs, and where to source supplies. I had planned to cover that in describing my recent 650B project (all done now!). However, as I prepared to write about it, I realised that would not really work. Being more of a re-build than a fresh build, I did not actually buy anything for that project other than spokes, so it won't provide an opportunity to discuss the thought process behind sourcing parts. So instead I’ve decided to dedicate a post to a hypothetical but very realistic build, starting from scratch.
A crucial part of the wheelbuilding process is the planning stage. Firstly, because we must make sure all parts are compatible. But just as importantly, because the feel, performance and weight of our end-result wheels will depend on the parts we start out with. Therefore, at the onset, it might help to ask ourselves some questions:
What are these wheels for?
Performance, utility, smooth roads, harsh roads, velodrome racing, hilly brevets... you get the idea.
Who are these wheels for?
Namely, the cyclist's weight, power output and riding style. A heavy and powerful rider will call for different build parameters than a lightweight, gentle rider.
Are there any special properties you want these wheels to have?
Superior comfort, aerodynamic advantage, crosswind resistance, extra stiffness?... It is good to decide in advance what is important to you, as some of these characteristics are in direct conflict with one another.
Do you care about the weight of the wheels?
If yes, what total weight are you aiming for?
Aside from this, you will of course need to know what size of wheels you are looking to build, and whether you want them to be clincher or tubular, rim-brake/disc-brake/rod-brake compatible, and so on... as well as your budget.
As we consider the answers to these questions, we start to realise there are countless possibilities. And since it would take a book to cover them all, I won’t attempt to do that. Rather I will use myself as an example and explore a possible build I am contemplating for the future.
So first, in answer to the questions above: I want to build a set of 700C performance wheels, tubular and rim-brake compatible. I weigh 60kg, and am a fairly gentle rider. I would like these wheels to give me an advantage in climbing and acceleration. I would also like the wheels to be crosswind resistant. My target weight is sub-1,300g for the set (not including skewers, cassette, or tyres). As far as budget, I would ideally like to spend not too much over €350, selling my remaining clincher wheels afterward to offset that cost.
With these parameters in mind, I begin to source the required parts: rims, hubs and spokes.
When choosing rims, factors to consider include: rim depth, rim profile, rim weight, and the number of holes the rim is drilled for. Because for my hypothetical build I am looking for climbing wheels that are crosswind resistant, I know that I need a rim with a low, rounded profile. I also know that I want the rims to be lightweight, and that at my weight and riding style I can get away with pushing the envelope in that regard.
So what constitutes a lightweight rim? The current consensus seems to be, that an alloy rim is lightweight if it is in the ballpark of 400g. If I can find one at sub-400g, that would be spectacular. I could also go the carbon fibre route and get the weight down further. But there are complications associated with carbon rims that I do not want to go into here, so to keep things simple let’s stick with alloy.
After searching far and wide, I’ve come across a few options. And here I mean literally just a few, because shallow profile rims that are also super lightweight and tubular, is not a popular combination these days (in fact, a good alternative approach would be to stalk eBay or local bike shops for NOS rims of 80s-90s vintage, when this combination of features was more common). But modern rims do exist that meet these criteria. And the best option I've found so far are the Ambrosio Crono Formula F20 rims. Described as "climbing rims", they are alloy, tubular, low profile, and they weigh 340g per rim! Priced at roughly €65 apiece, depending on the retailer, the cost is very reasonable. Sounds like I've found my rims.
Now onto the hubs. The rims I chose are available in 28/32/36 hole versions, and the hubs will obviously need to match. Opting for the lower spoke count option (though still not "low" by contemporary standards), I am looking for a lightweight hubset with 28 holes.
And what is considered lightweight in the world of modern hubs? Short answer without getting too deeply into it: around 100g for the front, 250g for the rear. It is not especially difficult to find hubs in this weight range across different pricepoints. But it's important to keep in mind other factors, such as quality, durability, and weather-resistance. Some hubs are more delicate than others, and this information is revealed in forum threads and reviews. If you find a hubset that you think might be right for your build, do some research on it before buying, or ask a knowledgeable seller for advice.
My own research led me to consider Bitex hubs. Specifically, I've heard good feedback from several builders now about the RAF12 and RAR12 (front and rear) models, which are said to offer a pretty good combination of light weight and robustness, especially for a low-impact rider such as myself. These hubs are available in 24/28/32 hole versions and various colours. The weight is 85g for the front and 215g for the rear. The cost is around €120 for the set, depending on the seller.
Once I have my hypothetical rims and hubs in hand, the "fun" can begin. And by fun I mean deciding on your lacing pattern (actually fun) and measuring for spoke length (not at all fun). You will, of course, now also need to decide which spokes to use.
Since I want to make my wheels as crosswind-resistant as possible, I am going to go with round (not bladed) spokes. And since I am going for "climbing wheels," I want lightweight double-butted spokes (pictured on left). Considering that the rider is myself, I know that I can go with lightweight spokes quite safely, especially since - with 28-hole rims and hubs in hand - I'll not be building a wheel with low spoke count.
So how much do "lightweight" spokes weigh? Now, some of the very lightest round alloy spokes available (again we are ignoring carbon here for simplicity's sake), are the mythical Super Spokes (1.8mm-1.4mm-1.8mm; 3.61g per spoke) from the Belgian manufacturer Sapim. However, they are hard to get even in Europe, expensive, and - as I understand from some wheel builders I've spoken with - not without their quirks. The next lightest option, and one I have ready retail access to, are the Sapim Laser spokes (2.0mm-1.5mm-2.0mm; 4.27g per spoke). Both my husband and I have used these spokes already in our first builds, so I already know that I like them and find them easy to work with. My "spoke dealer" Ryan (yes, he's as exciting and dangerous as he sounds) offers excellent prices on these, and a bundle of 56 (28 per wheel x 2 wheels) will run me roughly €38.
Now as far as lacing patterns... I see this as an entirely subjective, individual decision. On my 650B wheels I did single cross in the front, then in the rear triple cross on the drivetrain side and radial on the non-drivetrain. I decided on this myself, after reading all sorts of
Of course when ordering spokes and calculating the total weight of a wheel build, let's not forget the nipples (or, alternatively, for the squeamish - "spoke ends").
Most spokes come standard with brass ones (roughly 1g per unit). Or, you can go for the lighter (.4g) and more expensive aluminium ones, with the added bonus of being able to get them in various colours, but also the added drawback of them being easier to crack while tensioning. A wheelset's worth bundle of festive aluminium nipples will run me roughly €12.
So! Now that I have hypothetically ordered all of my parts, let's total up the weights and costs and see what we've got here:
Ambrosio Crono rims (2): 680g / €130
Bitex RAF/R12 Hubset (1): 300g / €120
Sapim Laser Spokes (56): 240g / €38
Sapim Aluminium Nipples (56): 22g / €12
Total weight: 1,240g
Total cost: €300
Holy smokes. Is that right? I had to check my numbers after I first calculated this, as it seemed too good to be true. But everything is correct.
The weight is impressively light by current racing wheel standards. And the cost is excellent compared to off-the-shelf wheels. Not to mention that the custom aspects of the build, such as its crosswind resistant characteristics, are not easy to come by off the shelf even at top prices.
I am not planning any new wheel builds just yet. But if I do decide to make myself a set of ultra-light climbing wheels, these are the parts I would use. I hope this breakdown was helpful (despite, for readers from other continents, the Eurocentric nature of the specs). If anyone would like to share their own builds - either real or ideal - I am sure we shall all find that extremely interesting.
And with that I bid you a Happy Weekend, pausing to remind you that unused aluminium "spoke ends" make for perfect holiday decor!
I know brass nipples are heavier and do not come in as many fancy colours, but for me and the sake of longevity it has to be brass. I had a wheel made just over a year ago, non disk xtr front hub and ceramic mavic rim, both found after long quests on internet. Hope to get over a decade out of it, last one did almost 15 I think, with several trueings. Even on my shorter lived alloy breaking surfaces I want several years and our British winters do cause small components to rot.
ReplyDeleteGenerally this is true. But even brass nipples are not immune to decay. You see those "golden" rims in the photos? That used to be a wheelset that my husband found god knows where for "hub harvesting" purposes. I took it apart to remove the hubs for him. Despite the nipples being brass (and they definitely are), they were extremely... I don't even know, corroded? Crumply and covered with white stuff and nearly merged with the spokes. Judging by the rear hub being a 10-speed, the wheels were not that old. Not sure what happened there, but clearly it *can* happen even with brass.
DeleteMy anecdotal experience involves two bikes, over the same five year period, each used roughly an equal amount, stored indoors but during daily use have spent all kinds of hours in all kinds of conditions. One with brass nipples the other with aluminum, both sets built and maintained by me, and brass has stood up better with less frustration. Also, you might mention greasing the threads….Did you do that? I've heard some use Loctite !?
DeleteTo be clear, the wheels I refer to above were not built or ridden by us; my husband got them used (and trashed, except for the hubs). No idea if the original owner greased the threads or not.
DeleteThe thread greasing seems to one one of those things where people have different opinions, so I decided not to go there.
Following the recommendation of someone with quite a bit of experience, we've used Loctite (jeez, my auto-correct wants to change it to "lactate" as if aware of the nipple theme!) on a couple of wheelsets now, after truing. But not for greasing; for securing the spokes once tensioned. On bad roads such as we have here I've discovered that even well-built wheels and factory wheels can come out of true quite easily. Loctite solves the problem.
I think Loctite is a mixed bag, like all things. You may think it solves one problem but it creates others. There are a lot of choices and issues, aren't there?
DeleteI have used Loctite for the same reasons as Veloria, on the recommendation of my LBS mechanic. I have yet to discover its dark side but now curious as to what that might be.
DeleteThere are many flavors of Loctite. Most common is blue. Other mfrs have equivalent products and they are almost always blue. Loctite will lock a nipple in place so solid it isn't moving again until you loosen it with a heat gun. You could get lucky with some threads and have an easier go of it but using Loctite you will meet times when that nipple will not budge. Aluminum nipples are specially bad in this circumstance, it is not hard to fracture them. Brass nipples don't easily fracture but they will round off or twist out of shape. Best procedure is to have a four-sided, three cornered spoke wrench at ready. They are slow to work with but a lot faster than sitting there with a heat gun.
DeleteOr just use purple Loctite in the first place. It is intended for small threaded parts and in particular small threaded aluminum parts. Very few shops would have purple in stock, you order it. Get the large size, the stuff is not cheap.
A drop of BOILED (not raw) Linseed oil is a great spoke prep for a build. Get your wheel strung loosely, then on the day you true and tension it take a piece of old spoke and dip it about an inch deep in the oil. Now touch the oiled spoke piece to the threaded hole in back side of the nipples (inside the rim) re-dipping it for each nipple. The surface tension of the oil will give you the right amount. The Linseed oil will give you the lube property to get good tension, and in a few days will dry to a gum like consistency. This will help prevent the spokes from loosening but they can still be adjusted if you need to re-true, certainly more so than with Locktite. Use caution in disposing of oily rags as the drying agent in the oil can cause spontaneous combustion. Dispose in an old can with water, never bundle the rags
DeleteI use linseed oil...lubricates the threads, but after an extended period of time (see "oil painting"), it dries to secure the nipple. But not so much that you can't turn it later on, as when re-truing the wheel
DeleteI have the purple Loctite. Purely a happy accident, as that is what the local hardware shop had in stock.
Deletere:spoked bicycle wheels, have you ever thought about the fact that with the tensioned wheel when the riders weight is on the bike it is hanging from the spokes at the top of the wheel like a suspension bridge,not being supported by the spokes on the bottom.
DeleteHi Ward, The idea that the weight is suspended from the top spokes seems intuitive but is easily proven false(I've been demonstrating it to people since good inexpensive spoke tensiometers became available). First take your tensiometer and check the tension values of the spokes with no one on the bike, now put a nice co-operative person on the bike and measure the values again.
DeleteWow...
If you wonder how this can be, just read Jobst Brandt's book on bicycle wheels. If it is a bit more than you can understand than just accept the fact that the explanation is complicated and difficult to understand if you aren't experienced in the field.
I first used a tensiometer in this way when I was about 19 (and a self acknowledged expert in practically every field) to prove that the weight was being supported by the top spokes and was ever so humbled to realize I was ever so wrong.
I got over it though...
Spindizzy
That's not how a prestressed structure works. All spokes are preloaded to a given value (100 kgf is fairly typical). When weight is applied to the axis of the wheel it is the bottom spokes that support this weight by REDUCING their tension, while the tension of the remaining spokes around the circumference of the wheel increases very slightly. The top spokes are the least affected of all.
DeleteThe quantity of linseed oil used in wheelbuilding will not support spontaneous combustion. That requires cubic feet of very oily rags. I am old enough to have witnessed those fires. A coach house I lived in burned just a month after I moved out. Fires really can happen but you won't do it with drops of oil on nipples. If you kick over the whole can and have to clean it up you could have a problem. Stop worrying.
DeleteAnother experiment. Even simpler. Stand an empty rim on the floor. Sit on it. If you choose the sort of rim illustrated in the Brandt book that rim will experience plastic deformation and the experimenter will quickly be sitting on the floor. Now try again with a flattish retro-look modern rim. If the experimenter is a heavy fellow the rim might bend and spring a couple millimeters. Try with a modern rim with some depth of section. Absolutely nothing happens when you sit on it. Not much happens to spoke tension when you ride that modern rim.
DeleteJust to chime in, one doesn't need be "old" to have witnessed oily rag fires. Most painters have seen them. Exciting stuff. And yeah, if every tiny quantity of the stuff caused a fire, imagine what havoc a classroom full of Oil Painting 101 students would wreak in art schools the world over.
DeleteI am always surprised at what topics can get people riled up. I guess "any" is the answer. Anyhow, if your comment in response to this thread was not approved, have a glance at the moderating rules.
With all the weight-weeniesm happening today, it's worth mentioning that your custom build may be good for your, but not necessarily good for others.
ReplyDeleteSub-1300g wheelset sounds great but should be generally used by lightweight people and in not-too-harsh way. I owned a pair of wheels with lightweight alu rims and bladed spokes. They seemed to work fine on pavement, but off-road they were noodles, especially considering 85kg of my body fat (I mean... muscles, of course). Now I have 1600g+ wheelset with more spokes and stronger rims and they are dead stiff even on really rough dirt roads. Those super lightweight racing wheels are designed for racing (duh!) and 75kg (or less) dudes, not for an average Sunday Joe with his beer muscle.
Yup (see: Question 2 - Who Are These Wheels For?)
DeleteIMO the characteristics of the individual rider are often not given enough consideration even in custom wheelbuilds.
I used a custom wheel builder for my last set and she was wonderfully inquisitive and helpful in matching components with my build, style of riding, and use of the bike. She even keeps files of builds for feedback! Best set of wheels I've ever had and I've learned to trust the pro!
DeleteThat is good to know, and you are welcome to share her website or contact details if you like.
DeleteSugar Wheelworks. https://sugarwheelworks.com/blog/
DeleteDon't forget everything else for the wheel, or you're going to be scrambling around looking for parts when you want to test ride it immediately: tires, tubes, rim strips, quick release skewers, cassette (and optionally spacer if the hub is built for more cogs than you have) and even spoke magnet for your cycle computer.
ReplyDeleteDisc brake users will need to remember about whatever parts are needed, depending on the system: proper size discs, disc carriers, bolts, lock rings, whatever.
Besides the spoke wrench, truing stand, and dish tool mentioned in the previous post, you'll also want the cassette lock ring tool and wrench to put it on. And chain whip (were there more giggles in the back there?) if you want to take it off. Spoke prep material depends on your philosophy of wheel building.
Me, I keep forgetting about the QR skewer- at least three times so far. It would probably be more but the other hubs I bought came with skewers. I have to scavenge a QR from somewhere and try to remember to get a new one whenever I'm at a bike shop, at a swap meet, or ordering online.
Oh of course. And you'll also need a bike to stick those wheels on, for that matter! : )
DeleteQR preference has recently become a "thing" for me after I managed to crack one (brand new, Mavic). A topic for future perhaps!
Several months ago it became clear I needed a new rim for my bike so I thought I'd just lace it in myself, buying the exact same rim and a set of new spokes and using my existing hub. This was nothing fancy and weight was not a consideration so I figured it was all standard stuff. So I went to my LBS and the rim cost $90, the spokes were $72 and if I had to replace the White Industries hub as well that would have been another $150. I notice you've got Campy Chorus hubs and did a quick search for price and discovered those are not cheap (several hundred for the pair) and I assume you had to buy them at some point. Just saying that it is indeed possible to build a set of wheels by oneself but if one is picky about components it's often much more than anticipated. Beware! Also, if one is switching from clincher to tubular there's also the price of new tires, too.
ReplyDeleteThe Campy Chorus hubs in the photos are an older model, extracted from a trashed wheelset that my husband bought for I think 30 euro. The hubs are fine, just the rims were damaged. This is the 2nd time he has managed to source really nice, secondhand hubs in this manner. It is weird, because the very same hubs, in the same condition, on their own sell for many times that price on the secondhand market. But attached to unattractive wheels they can magically become cheaper. I do not have the talent or patience to scour gumtree and eBay for finds like this, but some folks are really good at it and can find major bargains.
DeleteDo not believe Velouria. Used hubs are JUNK and should never be used regardless of condition or brand. Do not believe Velouria, do not bid on nice used used hubs on E-bay. Do not believe her LIES. Used hubs are valueless. Used hubs are valueless...
DeleteFurthermore, do not use used hubs on your bicycle or do anything that might increase the value or acceptance of used hubs as viable when building inexpensive wheelsets. Remember to tell your friends that USED HUBS ARE BAD.
Send all used hubs to Spindizzy.
I recently laced up a set of custom touring wheels for my 1986 Panasonic Touring Deluxe build (http://cyclelikeastringer.blogspot.com/2016/09/built-for-long-haul-1986-panasonic.html). Picked up a pair of 36-hole 700C Velocity Dyad touring rims on Craigslist locally for $40/pair and a set of period-correct Shimano 105 hubs for about $65 on Ebay. The straight-gauge spokes set me back just under a buck a piece. That brings the total to around $180. The finished wheels are absolutely bulletproof and will very likely outlive me. Admittedly, it was a lot of work and was quite tedious, but the process was incredibly rewarding. I'm not sure I'll ever be able to buy off-the-shelf wheels again.
ReplyDeleteNice! Thanks for the link.
DeleteOne more bit of research. Before putting your money down go to YouTube and listen to what the Bitex hub sounds like. I wouldn't have that racket on my bike. Others might, you can find riders talking about how to make their hubs louder and more annoying. The Bitex hub is less loud than many current hubs but is grating to my ears.
ReplyDeleteI guess I am neutral about hub noise. I would not deliberately opt for a hub that makes noise, but neither am I bothered if it does. A silent alternative to Bitex that is similar in weight and price range to consider would be Novatec. But Bitex has a much better reputation for weather resistance and that's a more important factor to me than noise.
DeleteJust keep pedaling! The angry sizzle of a coasting hub is proof you're laying down. The hell's wrong with pedalling?
DeleteSizzledizzy
On my touring/brevet bike I have an old XTR rear hub, which is nearly silent. I love how quiet that bike is. On my road bike I've got a mavic hub that makes an ungodly racket, so I just don't stop pedaling when I ride it.
DeleteI was out riding one day and a gentleman passed by on a road bike, whenever he coasted the bike (hub) made the most excruciating noise imaginable. The bike was a modern and doubtless expensive race bike, I cannot understand how anyone would want to hear that cacophany. If my bike came equipped with something like that it would be a quick return trip to my bike Shop to have it removed and replaced with something more environmentally friendly.
DeleteThere were F20 rims that weighed as little as 320 grammes a long time ago. Currently you are more likely to see 370 or 375, with 350, maybe, for the light one in the pile. If hitting some target weight is all important weigh them before you buy them.
ReplyDeleteIdeally yes. Sadly, this is an item unlikely to be laying around the LBS. On the other hand, it is possible that some sellers might be willing to weight-check the rims, if you phone and ask before buying.
DeleteI have had occasion to do just this exactly three times over the past fifty years of wheelbuilding. Stack of rims in a warehouse and a scale. The differences between rims were startling. Other rims, notably Araya and Campagnolo, are always the same. Usually there are many limits on choices.
DeleteAs a representative of the miser contingent of LB readers, I offer my method of measuring hubs and rims for spoke-length purposes using only materials you probably have lying around. This is good for the miser not only because you don't need to buy tools, but also because you can use it on your old, obscure, unlabeled, salvaged and modified parts, which will not be listed in any online spoke-calculator's database.
ReplyDeleteYou need: some paper, some thin cardboard, a stiff piece of wire, some paint or ink, scissors, and a ruler graduated in millimeters.
To measure hub flange diameter: Bend the piece of wire in half, with the ends about as far apart as your flange diameter. Try to stick the ends in two opposite spoke holes. Adjust the bend until it just spans the distance. Make sure it's not flexing and is staying at that distance when you let go. Holding the wire gently so as not to flex it, dip the ends in paint or ink, then print the two dots on the paper. Let dry and measure with the ruler.
To measure flange-to-locknut and flange-to-center distances: draw two circles (by hand) on the cardboard with diameters about equal to the outer diameters of your hub's flanges. Cut them out with the scissors. Make axle-size holes in the centers (the point on the end of a scissor blade will work well enough) and fit them over the ends of the axles. Secure them with axle nuts or or just push them firmly against the locknuts. Trim them if necessary to make them stick out about as far as the flanges. Roll a bit of the the edges of the cardboard circles and hub flanges in a little paint or ink. Roll the whole thing on paper to print four parallel lines. Let dry. Holding the ruler square (by eye) with the lines, draw a line across them all. Then, using the ruler, find the center and measure the spaces. Use the inner edges of the lines made by the cardboard circles to indicate where the outer surfaces of the locknuts are.
To measure effective rim diameter (ERD): Lay a rim on a big piece of paper or a broken-down cardboard box. Place one spoke in a spoke hole, screwed into a nipple so it just reaches the bottom of the screwdriver slot. Do the same with another spoke in the opposite spoke hole. Use the edge of the ruler to align the two spokes with each other and mark the paper or cardboard where the bent ends reach. Then take the spokes out of the rim and put the nipples back on in the same way. Place the bent ends on the marks, align the spokes again along the edge of the ruler, and mark the paper or cardboard at the points where the bottoms of the screwdriver slots are on each nipple. The distance between those outer marks is the ERD.
Enter your measurements into the online spoke-length calculator of your choice. I've used this method with success.
Walter
Thanks for sharing your method. We did something similar, except also used calipers.
DeleteAnd re this -
"...you can use it on your old, obscure, unlabeled, salvaged and modified parts, which will not be listed in any online spoke-calculator's database"
OMG. I would say, even if the parts are modern and ARE listed in a database, have the parts in hand and measure for yourself. When calculating spoke length for both our first builds, we found inconsistencies between actual measurements and listed specs. My guess is, sometimes the dimensions change ever so slightly from one year of production to the next.
Plus one for Walter.
DeleteRe prepping spoke threads, why not just use Wheelsmith Spoke Prep or Rock & Roll "Nipple Cream" rather than Loctite or Linseed oil? Both are designed for this task, are inexpensive and work perfectly.
ReplyDeleteQ: Why are academic battles so hard fought and so bitter?
DeleteA: Because the stakes are so trivial.
But seriously. Those products you mention are not perfect. I could do better. I know everything, of course I could do better. Linseed is very definitely a lot cheaper than proprietary. And blessed by ancient tradition. Myself, l build dry and add a half drop of linseed from above afterwards. Less seeps into the threads that way, but it is enough and is less likely to jam the threads than just dipping the spoke beforehand. Zero expectation that anyone will grasp the wisdom of my technique and imitate me, so I have something unique going here. Then for aluminum nipples, which no longer evoke any enthusiasm from me, tried every possibility, thought they were all bad, read the Loctite catalog, gave the purple a try and it was good. Then on driveside rear some of us use oil, lubricating oil, and this is such a dark secret I hope none from the guild are reading as I disclose this.
I have, in dark moments of rebellion, used Never Seez on driveside threads where the loads get so high that you can damage the nipple flats before you even finish building the wheel.
DeleteThe Guild knows I've done this and they have so far turned a blind eye...
Spindizzy
Some notes about how rim and spokes support a load. The rim does not often contact the road. The spokes do not contact the road. The tire contacts the road. The tire passes load to the rim either by the bead wire or through the glue bed on a tubular. The contact patch of the tire is some distance from the bead. The contact patch loads the cords in the tire casing . The weave of the casing is at an angle to the bead and the contact patch. The angle means that the immediately affected section of bead wire is much longer than the contact patch. And the bead wire itself is under tension and is moving load around past where the casing cord directly loads it. Of course the wheel is turning and the load doesn't sit long in one place. (Partial exception to that - performing a track stand .) The longer the contact patch, the greater the diameter of the casing, the greater the diameter of the wheel, the lower the tire pressure, the more the load is spread. Only after all that do we consider the arch strength of the rim. With a strong enough arch the load is transferred to the entire wheel and not just the bottom spokes. Even the lightest flimsiest vintage rim has some arch strength. Modern rims are so strong the load is pretty much always spread over a very large portion of the rim. A modern rim should be super easy to build and last until the brake track wears out. With disc brakes the rim should not wear out. Unfortunately there are a lot of other aspects to rim design and it is rare to find a rim that scores well on all bases. And then there is the matter of quality control, which the moderns find very difficult to manage.
ReplyDeleteWell here's a coincidence! In the next week or two, I'm going to be picking up a brand new wheel from your "spoke dealer". I've previously built a pair of wheels under his tuition, which was a good experience, but didn't fancy building my own this time (and the labour turns out to be a minor part of the overall cost). He is indeed a nice guy, even exciting, but... dangerous? Really?!!!
ReplyDeleteDangerously helpful with spokes &parts purchases : )
DeleteOne of my requirements (not mentioned here but not strictly speaking the wheel, I guess) is that the freehub / freewheel "picks up" quickly. I find rear wheels where the crank moves perceptibly before engaging feel.. er.. baulky :-)
ReplyDeleteThat is so cool that you build you own wheels now!!! To me this one particular connection to bikes is something like a brotherhood (I suppose frame building would be another, and you've done that as well!).
ReplyDelete