Making Strong and Durable Wheels

jan_pbp_2015

When building a bike, one important decision concerns the wheels. How do you get the best performance and still make your wheels strong enough to withstand 20,000+ miles of riding on rough roads without needing service?

By now, most cyclists know that spokes don’t break from overloading, but from fatigue as the spoke is loaded and unloaded when the wheel rotates. The wheel flattens at the bottom, which unloads the spoke at 6 o’clock. With each wheel revolution, every spoke passes through that spot, where it is slightly detensioned, and then tensioned again. Over time, that causes the spoke to fatigue.

laser-det_0

To get the maximum life out of your spokes, you want the detensioning to be as small as possible. That is what double-butted spokes (above) are for: They are thinner in the middle, so they can stretch more, which means that they don’t detension as much as a thicker spoke would. Yet the ends, where spokes fail if they break, are thick and thus will last a long time. It may seem counterintuitive at first, but the thinner mid-sections make double-butted spokes more durable than thicker straight-gauge spokes.

PinchParisRoubaix

Wheels tend to go out of true when you hit a bump and a spoke detensions so much that it goes slack. As the spoke is tensioned again, the nipple unwinds a bit. Now the spoke has less tension, so it will go slack more often, allowing the nipple to unwind more and more… For more information about the basics of wheel building, I recommend the late Jobst Brandt’s excellent book The Bicycle Wheel.

Now, let’s look at the specifics of building a strong wheel.

HerseCH1225

How many spokes do you need? For many years, 36 spokes was the standard (above), then it became 32 as modern spokes became stronger. On my René Herse (top photo), I use a 28-spoke front wheel. I built the wheel six years ago and never touched it again. If the rim hadn’t cracked (different story!), I am sure it would still be going strong today.

bump_big_tire

We can use fewer spokes, because the wider tires we ride today transmit far fewer shocks to the rim. Imagine hitting the bump above with a 23 mm tire: Even if you don’t bottom out, your tire is so hard that much of the impact will be transmitted to the rim. The big, soft tire not only transmits less shock to the rider, but also to the rim.

With smaller 650B or 26″ rims, the spoke bracing angle is greater, which makes the wheel stronger as well. That means that 28 spokes are plenty, even for rough roads.

herse_outback

However, the SON Delux hub I usually ride on my Herse has very narrow flanges, which results in a smaller spoke bracing angle, negating the benefits of the smaller 650B rims. For the Oregon Outback 363-mile gravel race, I put on a wheel with an old SON20 generator hub that has wider flanges (above). When you negotiate rough terrain, your wheel can slip while it’s pointing sideways, then suddenly catch and regain traction. If the wheel is not strong enough, it can collapse into a potato-chip shape, and your ride is over.

sonwi

We wanted a wider spoke bracing angle, so we asked Schmidt Maschinenbau for the Wide-Body Delux hubs, which have the widest flange spacing possible and thus build into the strongest wheels. Compass now offers these hubs in 28 holes, in addition to the 32h and 36h that have been available for a few years. If I had a Wide-Body hub on my bike, I would have been perfectly happy with 28 spokes for the Oregon Outback.

shimano_disc_blogThere are cases when a front wheel with more than 28 spokes makes sense. With disc brakes, your flanges are more narrowly spaced to make room for the rotor – that is why there is no Wide-Body Disc hub – and the entire force of braking is transmitted by the spokes. In this situation, a 28-spoke wheel usually is OK, but 32 spokes gives you an additional margin of safety. The same applies for 700C wheels (larger-diameter rims result a smaller spoke bracing angle), or for very heavy bike/rider combinations. For tandems, I’d go with 36 spokes.

son_delux12_silver

Compass offers the excellent SON Delux Wide-Body hubs with 28, 32 and 36 holes, so you can choose the spoke count that is right for you. We also offer the Delux for disc brakes with 32 holes, both in quick release and thru axle versions (above).

What about the rear wheel? Here, too, the answer is: “It depends.” If you have a strong rim, then 28 spokes may be enough. When HED send us test wheels with their Belgium rims a few years ago, they used 28 spokes front and rear, and they held up fine even when we rode them on mountain bike trails. One reason is that the rear wheel never sees significant side loads.

However, the rear wheel has a much narrower spoke bracing angle to make room for the freewheel/cassette. That is why British builders often used rear wheels with 4 or 8 more spokes than the front. I did the same on my René Herse, which has 36 spokes on the rear. Most wind tunnel studies indicate that the rear wheel is in such turbulent air that its aerodynamics don’t matter much, and the little extra weight isn’t a big deal, either.

Next, let’s talk about rims: Most rims today are stiff and strong. If rims crack, it’s usually caused by poor design or sub-standard materials. Once you’ve eliminated those problems, what you want from your rims is a good fit of the tires. With classic rims, it needs to be good enough to seat the tire automatically as you inflate it. And the tire shouldn’t come off even if you have a sudden blowout on the front. With tubeless-ready rims, the fit needs to be even more precise, so the tire seals easily and doesn’t blow off the rim despite lacking a tube that reinforces the joint between tire and rim.

theo_bike

Compass offers three rims:

  • The Grand Bois rims are a proven classic, available with 36 holes. The polished finish is beautiful, and the tire fit is very good. However, they aren’t compatible with tubeless mounting.
  • The brand-new Pacenti Brevet rim combines classic appearance with tubeless-ready construction. Compass has them in stock in 28 and 32 holes.
  • The HED Belgium Plus is a modern, lightweight, wide semi-aero rim. It is tubeless-compatible, with a tire fit that is consistently excellent. A few of us have been riding them for a few years now (above Theo’s bike), with zero need for truing and easy tire mounting. Black anodized and available in 28 and 32 holes for rim brakes, and in 32 holes for disc brakes.

For each of these rim/hub combinations, we now offer spoke packages with the highest-quality, double-butted, superlight Sapim Laser spokes (2.0 – 1.5 – 2.0 mm) and aluminum nipples. That makes it easy to build a generator hub wheel that is perfect for your intended use: Just select your hub and your rim, and then order the spoke package that goes with this combination. (We also offer the spokes individually.)

Click here for more information about Compass wheel goods.

About Jan Heine, Editor, Bicycle Quarterly

Spirited rides that zig-zag across mountain ranges. Bicycle Quarterly magazine and its sister company, Compass Cycles, that turns our research into high-performance components for real-world riders.
This entry was posted in hubs/rims, Lighting. Bookmark the permalink.

52 Responses to Making Strong and Durable Wheels

  1. Stefan says:

    Hi Jan,

    do you really think that aluminium nipples are a good idea? Brass is more durable in my opinion.

    • In the old days, some aluminum nipples were indeed awful. I once bought a used wheelset with aluminum nipples, and they broke one by one. Granted, I was pulling a trailer with the bike, which greatly adds to the stress on the rear wheel.

      Modern aluminum nipples are much better. We tested a number of wheels with aluminum nipples and no trouble.

      • DaveS says:

        In this case, how long ago was ‘the old days’? What changed so that the new aluminum nipples are better? There are plenty of touring wheel horror stories that were deemed to be caused by aluminum nipples (including fairly recent ones in the last several years). Are they using the wrong aluminum nipples? Maybe wrong root cause?

      • There are plenty of touring wheel horror stories

        I think most touring wheel horror stories are caused by people riding on factory-built wheels. A set of hand-built wheels will be properly built and stress-released, so it’ll last forever. Factory-built wheels really should be considered an assortment of parts. Detension them completely and start over when they are new (before the spokes fatigue). That way, you can get a decent set of wheels (except most use straight-gauge spokes). But riding them as-is isn’t a good idea.

      • Charlie says:

        Let me echo DaveS in asking how old were the old days? I dread seeing older Wheelsmith-built wheels come into the shop because the alloy nipples are usually corroded and they crumble while I’m struggling to break them free from the Spokeprep.

      • Neglected bikes always are tough… Here is what I used to do before truing my wheels: I put a drop of oil on the spoke just above the nipple, then went for a ride. The oil penetrated the nipple and made it easy to turn. Lately, I haven’t had to true wheels any more, because the wide tires we now ride don’t transmit the same shocks.

  2. Gugie says:

    I started building wheels in my teens for myself. During my LBS days in my early 20’s I built a few hundred, then back to mostly for myself and friends in the past few decades. The one thing I’ve stayed away from is aluminum nipples except for “race day” wheels, and then only for time trial/triathlete applications. They wrench faces are very easy to strip (the threads seem to hold up fine), but once you can’t turn them with a spoke wrench, they’re shot. One of the skills I think any serious cyclists should have is to true a wheel on a bike. Unforeseen things can happen on a ride, being able to true a wheel back into shape can mean the difference between finishing a ride and using the “call of shame” to a friend.

    I took a look at the Sapim site, it appears they’re using a 7000 series aluminum vs the typical 6061 alloy of the past. Does anyone have experience using these? The claim is they don’t round over as easily (deformed wrench faces). Is this true?

    I’d be interested in trying them but not for weight savings. Sapim is making the claim they are superior in other ways. At around 200 lbs, I’m not so worried about saving a few grams in my wheels!

    • See my response above. In the past, some aluminum nipples were indeed awful. Today’s aluminum nipples are much stronger.

      • Jason Dul says:

        For me, brass vs. aluminium is less a strength issue, and more a corrosion and seizure issue. Especially here in the midwest where there’s tons of road salt in the winter, aluminium nipples have a higher rate of corroding and seizing up, even when properly prepped during the build. I’ll build with them, but I’ll warn people against them if we’re discussing an all-season wheel.

      • For a commuter bike, I agree that brass nipples are a good choice, too. We’ll probably offer them in the future. In any case, they are easy to find, unlike spokes in specific lengths.

    • Rob Trageser says:

      If you are running a tubeless set up , be very careful how you apply rim tape. Working in a shop, Ive seen quite a few alloy nipple failures from sealant leaking into rim and eating the nipples away! Lots of sealants have ammonia in it. Nipples will start breaking ,you’ll start having all sorts of weird issues and the mechanic will start chasing his tail!
      Just use brass! If youre that worried about weight change you diet!

      The other problem we discovered was bikes that are stored near pool chemicals. Spokes will break in the middle!

  3. Kerry Irons says:

    While going with lower spoke count for front wheels has some attraction, any performance improvements are vanishingly small (slight weight reduction, slight aero drag reduction). Some of use choose equal spoke counts front and rear just to simplify maintenance – both wheels can be built with the same length spokes. While many builders use different length spokes for DS and NDS in the rear, that is not really necessary nor does it offer any significant improvement in wheel durability.

    • Using same length spokes all around is appealing. Classic Maxi-Car hubs had the spoke holes on the drive-side set a little closer, so the spoke length was the same on both sides and the front. (They also had keyhole spoke holes that made it possible to replace all spokes without removing the freewheel.)

      If you use a generator hub, the spoke lengths will be different anyhow, so there is no penalty to using different spoke counts. That said, Compass offers generator hubs with three spoke counts, giving you a choice.

      • And if the wheels have the same rims and are laced with 36 spokes X4, the spoke length will be the same regardless of flange size, to the extent that it matters.

      • Peter T says:

        For what it’s worth, you can build a generator disc wheelset with the same length spokes everywhere. I’ve used a Shutter Precision PD-8 front and a Deore XT rear. Spoke calculators will tell you to use slightly different spokes but in practice it makes no difference.

        I’m surprised that you use aluminum nipples. Aluminum and steel are notoriously bad for rusting together. Brass is the perfect metal for this application, bonding neither to the aluminum rim or the steel spoke. What makes you choose aluminum? I’ve read elsewhere in the thread your note that “they aren’t as bad as they used to be”, but this is hardly a glowing recommendation over the proven brass.

      • The spoke kits we sell are for front wheels. I’ve used alloy nipples on the front wheels of my bikes for many years, with zero problems. So I am pretty confident to endorse them for front wheels. The price used to be prohibitive, but Sapim’s aren’t much more than brass. So that is why we offer them.

        For the rear wheel, I’ll build my next wheelset with alloy nipples to gain some long-term experience. Various test bikes have had zero problems, so once again, it looks promising. We’ll probably offer brass nipples in the future for customers who ride on salty roads a lot.

  4. Sean says:

    Any possibility that you may offer complete wheels? I would love to have wheels made using the parts that you offer, but lack the skills needed to build wheels. I also do not have a local wheel builder in my community.

    • We’ve been thinking about it, but unfortunately, we are too busy to offer complete wheels at this time. There are many competent wheelbuilders. For example, I believe Feldman’s Bicycle Repair ships his wheels. We wholesale all the parts, so whichever wheelbuilder you choose can order them from us.

    • Matt Sallman says:

      “but lack the skills needed to build wheels.”

      I had always thought that, but reading the wheel building suggestions from a couple sites – including Sheldon Brown – I bought some Grand Bois rims from Compass and some spokes and gave it a try. It was much easier than I thought. The key thing is to have patience for the truing phase.

      My wheels have served me well for three years now. I recently had something bend two spokes while the bike was in my car, but having bought extra spokes at the time of the build I was able to fix the wheel in minutes. I just swapped the bent spokes and tightened them to where the tension was even using the spoke pluck method and when I tested the wheel it was still perfectly true.

      Good luck,

      Matt

      • It’s great that wheelbuilding has been such a success for you. You are right, it isn’t that hard. To check the spoke tension, you don’t need a tensiometer: Plucking the spokes like guitar strings will give you an indication whether the tension is even or not. You don’t need to be musical, since you are looking for big differences in spoke tension. (Small ones are inevitable as you true the wheel.)

        something bend two spokes

        You can also straighten the spokes, unless they are damaged.

    • Rob Trageser says:

      If youre somewhat mechanically inclined and have a good amount of patience you can learn to build wheels. Get the Jobst Brandt book! Thats how I learned. I learned on my own in 80s. I had an expert wheelbuilder critique my wheels. Now I work in a shop for fun and Ive probably built several hundred wheels. The key is in all the little details such as lubing spoke threads and rim holes,improving spoke line and stress relieving. Dont rush the process, take your time to learn!

  5. bruce h says:

    I just re-read “the Bicycle Wheel” by Jobst Brandt, RIP. It’s a book recommended for anybody interested in the subject in some detail aka bike nerds. I’m still riding a set of wheels I laced up 30+ years ago: DT spokes (not butted); 4 cross, high flange hubs. I’ve probably replaced 15-20 spokes in that time on the wheels.

  6. Conrad says:

    I’ll add my 2 cents as someone that builds my own wheels. Building a rear wheel with box sections rims and a modern (wide) cassette is challenging. You need 90kgf on the drive side for a wheel that stands, but over 120 kgf and you risk cracking a box section rim. It can be done but your wheel building skills need to be sharp. I feel that I can build a much better wheel, with more tension on the left side, with an asymmetric rim like the Velocity A23. The V section rim can take loads of tension without cracking. I have not had problems with judicious use of high quality aluminum nipples. I don’t use them on the drive side of the rear wheel though. A good spoke wrench is necessary to avoid rounding them out. I would be a little careful with 17 gauge spokes on a 28 hole front wheel. I folded over a well built such wheel in a cyclocross race once. Not crashing, just driving through thick mud. Thank you for offering these spoke kits. “Normal” hand built wheels make a lot of sense from a performance and value standpoint but the industry at large seems to be forgetting about them.

    • you risk cracking a box section rim

      Some older Pacenti rims used a true “box” section with a flat top. That was a poor design that led to cracking. Every other classic rim I have seen had a domed box section. The older rims were more domed, and rarely cracked. Mavic’s classic MA-2 wasn’t quite as domed and sometimes did crack, although I rode them for tens of thousands of miles without problems.

      I agree, however, that building modern, high-dish rear wheels is much more challenging than building traditional wheels. I recommend that anybody who wants to learn wheelbuilding start with a front wheel. It doesn’t have any dish, so it’s much easier to build.

  7. Edwin says:

    As usual, a very informative and well written post.
    One question: What is the difference in bracing angle for a 622 wheel vs 559 wheel? Does it really make a big difference? I always thought the reason smaller wheels were stronger was due to shorter spokes (harder to break a 2″ dowel than a 6″ dowel of the same thickness kind of thing).

    Thanks!

    • The bracing angle difference is significant, about half a degree. Since you start out with a narrow 7° angle on a typical front wheel, that makes a difference.

      Unlike the dowel you mention, spokes are in tension, not compression. Longer spokes are more robust, because they can stretch more. Motorbike makers found out when brake drums got bigger and rims got smaller, resulting in very short spokes. Suddenly, spoke breakage was a real concern, especially on motorbikes with sidecars that put sideloads on the wheels.

      • Stefan says:

        One comment on the wording (for the whole article). In my opinion it should not be called “stronger” wheels or spokes but “more durable”.

        Spokes with equal cross sectional area are equal strong in terms of the force they can bear, but they have a different fatigue lifetime (durability) cause the strain difference when riding the bike is different. Also for example non butted spokes are stronger (force) but less durable (fatigue) then butted spokes.

      • You are partially correct: The thinner spokes make wheels more durable. However, the wider flanges make them stronger. So I’ll change the headline to “Stronger and More Durable Wheels”.

      • Bill Gobie says:

        Strength is not quite the right word; longer spokes are more robust.

      • You are right. I’ll correct my comment!

      • Stefan says:

        In reply to your reply below (can’t reply there anymore): you are right, my comment pointed just on the spokes. Wider hubs make the wheel lateral stiffer, still not sure if stronger is the right word here.
        But thats splitting hairs and does’nt really matter, everyone knows what you mean 🙂

  8. tbone408 says:

    I’ve seen lots of people get away with it, but Sapim Laser spokes shouldn’t be used for disc brake applications.
    http://www.sapim.be/sites/default/files/checklist.pdf

    • We checked with Sapim on that. The comment is in the section on mountain bikes. Their concern is hitting huge bumps (with full-suspension bikes) while braking hard (so the spokes are loaded). The wheel parts we sell are intended for Allroad bikes, which usually don’t have suspension and are used on pavement, gravel and moderately rocky terrain, so the thin spokes are fine.

      The link you mention has a lot of good advice about wheelbuilding in general.

  9. Ian Michael says:

    Have you investigated the directional spoke-hole drilling of the ANDRA series of rims offered by RYDE in the Netherlands? Perhaps you could acquire a set of their 650c rims and share with us your results based on similar criteria, particularly bracing angles, large diameter flanges, and the spoke stresses of various cross patterns?

  10. David Pearce says:

    Goodness, goodness, goodness! How good are Jan Heine and the whole team! I’ve been too busy to read Off the Beaten Path for too long a time, but I’m sure glad it’s there!

    Reading back over past blog entries, written so nicely and succinctly, with beautiful photos — it’s just a feast for the eyes and mind:

    –Your centerpull brake backing plate and the added bonus of Tucker-Cord transmission just-in-time thinking.
    –Bicycles dressed up for the holidays with Christmas tree lights!
    –Such wonderful description of Bike Shop Gen. Wonderful discussion of the Porta Catena AND it’s lockout-shifter. (Makes me think of the line from the David Bowie song “This Is Not America”:
    “There was a time . . . . when I could see the biggest sky,
    And I could have the faintest idea!”
    –Happy New Year!
    –Disc brake essay and 161 responses allowed. Lively!
    –Reducing environmental impact.
    –And too many more ideas to even list!
    –And essay on strong wheels. I don’t EVEN know what bracing angle IS, but I know YOU know, and that’s the important part.

    The bicycle never ceases to amaze me. It really has been proven and improved by thinking and riding and trials, and it really is remarkable. And the nice thing is, we humans did it. With all the people in the world who want to make war, blow things up, and make chaos, we bikers have striven to make things more orderly, more perfect, not less.

    Thanks for bringing it all to me, and us!

    • Thank you for the kind words! Spoke bracing angle: Seen from the front of the wheel, spokes and hub form a triangle. If the angle at the top of the triangle is too narrow, then the wheel won’t be very strong. (In theory, it could be too wide, too, but with bicycle wheels, the angle is always on the narrow side, so wider is better.)

  11. Caleb says:

    I’ve built a few wheelsets with Wheel Fanatyk’s splined alloy nipples, but only in the last year, so while they are indeed nice for building, I cannot confirm the merits WF espouses. Similarly to BQ, though, what I read from Mr. Hjertberg has me confident in their performance until evidence may suggest otherwise. Does anybody here have experience with their nipples? Do you have thoughts on them, Jan?

  12. jasonmiles31 says:

    I’d be interested to hear your thoughts on radial lacing on rim brake front rims. Radial lacing seems to be the default pattern for racing wheels as it creates a lighter, stiffer, easier to build wheel. The other advantage for wheels using straight pull spokes is easier to drill hubs flanges.

    I guess the shorter spokes (less stretch) and torsional loading might offset the gains in a touring setup.

    • I know where you are coming from: When my friends and I built our first wheels at age 19, we radially laced the front wheels, figuring that there was no need to cross the spokes. We discovered that there were two disadvantages:
      1. The wheel is less stiff laterally. It’s not a big deal, you notice only when doing a track stand (and perhaps when riding out of the saddle and rocking the bike from side to side).
      2. The hub flanges must be designed to be stressed in that direction. The beautiful low-flange Campagnolo Chorus hubs I used weren’t, and one flange broke 5 years and 40,000 miles later. I was able to limp home with three adjacent spokes missing. I built a new wheel with traditional crossed spokes. I learned that with bicycles, things often are a bit more complex than they seem at first sight.

  13. What is the approximate cost of a “starter set” of tools needed for a beginner to perform a high quality wheel build?

    • The tools aren’t the problem, it’s the skills. I built my first wheel with an old fork as a truing stand. I suggest you take a wheelbuilding class. You can use the shop’s tools during the class and learn the skills. It’s great fun to build wheels – I highly recommend it!

    • Gugie says:

      I recommend a good spoke wrench. A bike frame and 3 tie wraps make a fine truing jig, dish can be checked by flip-flopping the wheel. I have a Park truing stand now, which is what I learned on back in my LBS days, and a dishing tool. These just make building a wheel faster and easier, but the quality won’t suffer.

    • Frank B. says:

      I would recommend the “Professional Guide to Wheel Building” by Roger Musson, available as an ebook at http://www.wheelpro.co.uk/
      It’s all you need to get started and to continue building wheels for a long time.

      • Caleb says:

        I second Frank B’s recommendation. In addition to useful information, the book has guides for creating your own effective tools at relatively little cost.

  14. Pawl Bearer says:

    I learned many years ago that potato-chip’ing a rim doesn’t always mean the ride is over. If the high spot in the center of the double S-bend is found and carefully hit laterally on the ground (hit the tire not the rim) while holding onto the two smaller bends, it is possible to return the wheel to a semi-round state and ride home. “For every action there is an equal and opposite reaction.” The goal is to undo the bending action that caused the potato-chip. In the long run, the stress from force truing a severely bent aluminum rim will cause cracks between spoke holes but you get to ride home. Wheel Fanatyk has a great blog post for fixing smaller rim bends: http://www.wheelfanatyk.com/blog/wheel-building-tip-no-7-replace-spokes-one-at-a-time/ Wheel Fanatyk’s method may even work better than the method I described.

    Great post! I want to try the super-butted 2.0-1.5-2.0mm spokes on my next wheel build!

  15. bikesnob28hb says:

    I have taken the liberty and provided the engineering background and proof why thinner spokes are more durable (Sorry, German only). Only for engineering nerds.

    https://cyclyng.com/2017/03/18/laufraeder-der-zeiten/

  16. Albert Kumnick says:

    I don’t understand your comments about spoke detension and resistance to failure. The load along a spoke is constant whether butted or not, so the strain (elongation per unit length) would be greater where the diameter is smaller. This would mean that the length of a spoke would change more if it were say 15/14 gage butted than for a constant diameter 14 gage as the spoke turned from max load at the top to near zero at the bottom (I am assuming a smooth road). If the process of making a butted spoke strengthens the small diameter region vs the rest of the spoke this would explain the observation, but at a given load the smaller diameter region is more highly stressed and seems like it would fail sooner.

    • What is key is how many millimeters the rim needs to be compressed for the spoke to detension significantly. For the same spoke tension, a thinner spoke has more elongation, so the rim can flex more without the spoke detensioning much. That means that as the rim spings back to its original shape, the spoke will also return to its original tension.

      If the spoke detensions significantly, the nipple will uncrew as the spoke springs back…

  17. Hidgolf says:

    With the Compass Rat Trap Pass tire, I am considering 26″ wheels for my next bike with rim brakes with the wide body SON dynamo and 28 spokes in the front, 32 rear. Does the group know of 26″ rims that fit a 50+mm tire with such drilling and rim brakes? I don’t expect more than 210lbs with me and cargo.

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