HI.

I posted at the begining of summer about my rear wheel breaking spoke after spoke, only on the drive side and followed the general recommendation of getting the wheel rebuilt. After 1500 kms (approx.) on my newly rebuilt wheel I broke another spoke last night on my way home.

The rebuilding job look good but I'm no expert, I will take the wheel back to the LBS tomorow and ear what they have to say about it.

I'm telling you all this because I'm starting to question myself about the whole weight on the bike. I'm at 215-220 pounds and I carry up to 40 pounds of lunch box, spare clothes and stuff on a low end triathlon bike with 700x23 tire/wheel. Am I to heavy for the wheel? I commute 55 kms RT 4-5 days a week on a very rough rural road, lot of big pot holes. The bike was not made for racks and panniers but I modified a few things to fit them anyway so I'm starting to think that it's too heavy

What do you think? Anyone as heavy as me on a similar bike?

you might want to tell them to use the heaviest spokes that are out there. I did that on both my road bike and mtn bike commuter and it worked great.

36 spoke heavy duty hand made wheels

https://www.nashbar.com/bikes/SearchD...rchTerm=vl-chd

I weigh about 205 and only carry around 20 pounds of stuff, but the only time I've broken spokes is when I've managed to put the chain into the rear wheel. I generally ride with 32-spoke wheels and 700x25/28 tires, though I did finally go with 36 spokes on the last wheel I built for my commuter. I used 24-spoke Mavic Aksiums on my road bike for a couple of summers, and they held up without an issue.

It possible that your LBS left a flaw in the wheel. It's also possible that the components just weren't up to the task. It's hard to say. Riding style makes some difference. Wider tires would also help, though perhaps you can't do that with your current bike.

I weigh in at a little more than the OP. I agree w/10 Wheels, nothing beats a hand built, 36 spoke wheel, with appropriate hub/spokes/rims (can't vouch for nashbar.com though). I typically break spokes on 32 spoke wheels w/in 3 months of purchase (OEM wheels). After the 3rd one or so, typically the LBS takes will cut me a break on getting a 36 spoke wheel built up (they charge the manufacturer for the difference due to warranty issues). Whenever possible/practical, I keep the old wheels off the old bikes and will use them as backups if I start to run into problems w/the new bikes (has yet to happen, but I'm not out any more money should it occur).

I don't think 260 pounds is really enough to expect to break spokes with. Although I might go with a high spoke count wheel

It's a 32 spoke wheel, I'll check for 36 spokes, I don't have money to change the bike, a 36 spoke wheel will be cheaper than a new bike
I could also lose weight but getting a new wheel will be easier and quicker

I agree with 36 spoke wheels, but I also recommend fatter tires. There is no reason to run 23mm tires on roads like that, carrying that kind of load. I would use at absolute minimum 28mm tires. 32's would be better if you can fit them. Your whole ride will be more comfortable too, and you might even get faster as you'll be more comfortable over rough roads.

Because you mentioned it is a tri bike, likely with short chainstays, I'm going to guess that you have the panniers set up pretty far back to avoid heel strike. Likely weighted mostly, if not entirely, behind the rear hub. If that is how you are set up, you are putting even greater stress on the rear wheel. Not much you can do to change that if you want to continue using panniers with that bike. As suggested, I would get a 36 spoke count wheel.

I'm under 160# but I'm a mechanical engineer and I like to have plenty of structural margin, so for my main commuting bike I built up a heavy duty 40-spoke 700C rear wheel (running 28mm tire). The last kind of avoidable failure I want to have when on a long ride, especially commuting, is a broken spoke. The extra mass of the heavy duty wheel is negligible, in relation to the peace of mind it provides me.

Glad I'm not the only one I broke one on the rear last week coming out of the drive way at work Welcome to the broken spoke club.Shift+R improves the quality of this image. Shift+A improves the quality of all images on this page.

I was breaking spokes like mad when my bike was new. I rebuilt myself with butted spokes and a double-walled rim (reused the hub). I never broke another spoke on that wheel. Eventually I broke the axle and replaced it but the spokes lasted > 16,000 miles.

The same thing happened to me 2 years ago... I broke at least 10 spokes on the rear wheel in 7000 miles.
I heard it was most likely not enough spoke tension, even though they seemed plenty tight to me (by feel).
So, I got a Park tension meter, and found that my tension was too low, but I was sure if that was the true cause.
I was surprised how tight a proper spoke feels by though.

Later, I got a new 32 spoke wheel, the spokes were at the right tension when new, but after just a couple of weeks some some got too loose.
So, I started checking every 6 to 10 weeks (1000 to 1500 miles).
In the last two years, maybe I broke one spoke. Perhaps it was tension, but I'm not planning to check the tension every 2 weeks.

Of course, 36 spokes would be better, but it could be your spoke tension.

When I built my wheel myself (my first wheel) I didn't want to spring for a tension meter. A friend who has done a fair amount of amateur wrenching said "just really lean into the rim then torque them down until you think you're almost ready to strip something."

I did that - got the spokes basically as tight as I could with my little hand spoke wrench and home-made from 2x4s truing stand. I equalized the tension by plucking the spokes and getting the pitch about the same, then trued.

In the 16,000 miles I rode that wheel, it never even went a millimeter out of true. Dead straight and no problems from the moment I put it on the bike.

Spoke breakage is ALL about the quality of the build, practically nothing to do with the quality of components.

If the spokes go into compression, they will fail. The spoke tension needs to be high enough that they never go into compression.

I am 300+ lbs; build my own wheels for quality and cost. Mine are all 36H or 40H. My favorite rims are Sun CR18, favorite spokes are Wheelsmith SS14, and on some wheels DH13.

As noted about - get wider tires; the widest that will fit in your frame and fork.

I've been building wheels for just over 20 years now, and successfully passed through that awkward "braking spokes" period a good 17 years or so back. In my experience, if a spoke breaks at the spoke head it's because the spoke head moved around in the hub flange hole. The other kind people posting here have covered the most typical cause of spoke failure, which is the spoke being too loose, but one other possible cause being if the spoke was too thin for the hub flange in the first place (for example Shimano hubs used to use a 2.4mm spoke hole so it was best to use a 2.0mm spoke [14g], whereas Campy hubs used a 2.0mm hole so a 1.8mm spoke [15g] worked best). This can also allow the spoke head to move back and forth in the hub flange hole, which stresses and breaks the spoke at the spoke head.

The OP mentioned that the wheel was recently rebuilt, and this made me think of another possible but often overlooked cause and that is if the hub was built using different pattern. When a hub is built and used with the spokes in one pattern (i.e. a mirror pattern) and is then rebuilt using the opposite patter (switching to a parallel pattern, in this example), the spokes on one flange will switch direction. If the outside spokes originally swept backward, they will now sweep forward (or vice versa...you get the idea). The problem arises because a spoke will commonly groove the hole in the hub, thereby widening the hole ever so slightly. When the hub is rebuilt with the spoke going the other way, the spoke hole gets widened even more, this time by being grooved in the opposite direction. The result is a spoke hole larger than it originally was, and a spoke head that is allowed to move around in the spoke hole. In my experience you can get away with switching from three cross to two cross with the spokes sweeping the same way, but that's about it for changes in pattern. This was pointed out to me by a very experienced wheel builder, and after I started heeding his advice my spoke breaking days were over.

To tell if the lacing pattern has changed look at the hub flange. If you see any marks from a spoke where there isn't a spoke now then the pattern has been changed. If you're looking at a spoke head but you see marks from a spoke next to it, or if a head down spoke sweeps one way but there's a mark from where it used to sweep the other way, then you may have a problem.

One other note: If you have a nice hub that's been built multiple directions and you want to save it, DT Swiss used to make these little brass washers to go over the spoke head to fill in the excess void space in the spoke hole. You can check with DT or other spoke makers to see if they're still available.

So, in summary: loose spokes break at the head. You want spokes to be tight yet even in tension and built on a hub using the same pattern as the hub was originally built. (By the way, excessively tight spokes don't tend to break at the head, but they can cause the rim to crack.)

Just a sampling of my success with my own wheels: I have one set I built in 2000, three rear wheels I built in 1998 (found some nice hubs at a bike swap), and even have a front wheel that I built in 1991, all road wheels. The 1991 front and one of the 1998 rear wheels I use pretty much every day (8 speed Dura Ace hubs on MAVIC Open 4 rims, how's that for a flashback!). I built the wheels on my touring bike, my mountain bike, my commuter, and most of the wheels on my wife's fleet of bikes. I've long since lost track of how many wheels I built for customers in the ten years or so that I worked as a bike mechanic. For comparison, I'm just over 200 lbs and ride between 5000 and 7000 miles per year.

As for the OP's concerns about whether the bike/wheel is appropriate for the demands of commuting: I've seen far heavier riders use 32h wheels successfully for years, but those were well made wheels built with good quality components. As for rough rural roads with lots of pot holes being the problem, those are the sort of things that will damage a rim but if the rims is okay then the spokes should be holding up (in my experience). Now if a rim is bent for any reason (such as from a pot hole) and the wheel is being forced to be true and round, the result can be uneven spoke tension, and that could cause spokes to break.

Hope this was somewhat helpful. Don't be shy about sending a PM if you have any questions that I might be able to help with. Good luck.

You're going to break spokes until you rebuild the wheel with quality spokes (I like DT) in the side(s) where they're breaking (drive side, non-drive side), bring it up to a uniform high tension on the drive side (110kgf is a start) and whatever it takes on the non-drive side, and stress relieve the wheel.

After that you can expected hundreds of thousands of miles out of the spokes which you can re-use as rims wear out.

Of course your chance of finding an LBS to do it for you are slim. You need either a one-man operation where the guy who earned the reputation will personally build your wheel or to do it yourself where it's more about patience than skill (as long as you can read and are willing to - Jobst Brandt test his book _The Bicycle Wheel_ by having his grade school sons each build a wheel set with no other help.).