Bicycle Mechanics - Broken wheel (CXP21)

I just went to check my wheel to see why the brakes were rubbing, and I found that it was broken! See the picture. I've got about 5,000 miles on these wheels.

Anyone have any ideas how this could happen? I rode over some train tracks on my last ride, but I ride across them all the time and have never had any problems. I'm 170 lbs.

Also, any suggestions on a new wheel? A sturdy one preferably :)

Thanks,
Tim

I should mention that I've had tons of problems with this wheel (Mavic CXP21). It kept going out of true and spokes kept coming loose. Finally, over 6 months ago, the guys at the bike shop retensioned it and put some locktite on the troublesome spokes, and it's been okay since then.

That seems to be a common thing with these wheels. Could it be related to it breaking like this?

Tim

cxp21 are road rims, right? you can use them for cyclocross, but....

how much do you weigh? you must have punished your rims so much :).

cxp21 are road rims, right?

Yep, this is on my road bike.


how much do you weigh? you must have punished your rims so much :).

170 lbs. Maybe the regular riding over train tracks finally got to them? :)

Tim

Yep, this is on my road bike.



170 lbs. Maybe the regular riding over train tracks finally got to them? :)

Tim

Tim, you're not suppose to ride your road bike on train tracks! :D :D :D
At least the only damage was the rim. Be careful, you might damage your fork, headset, hubs.. These are not designed to be ridden off road..

I strictly ride my roadbike on road...

Tim, you're not suppose to ride your road bike on train tracks! :D :D :D
At least the only damage was the rim. Be careful, you might damage your fork, headset, hubs.. These are not designed to be ridden off road..

I strictly ride my roadbike on road...

I can't tell if you're joking :) So I'm just going to clarify... Of course I'm not riding my road bike offroad over train tracks. It's the train tracks that cross the road that I'm talking about... The train track crossings are in bad repair around here; it's almost like riding offroad! :D

Tim

They should last longer than 5000miles, however as you say that the wheel has been not staying true and spokes loosening I bet the wheel has been cracked for some time(It is probably also cracked around some other eyelets)
This can happen when the wheel is overtensioned or from a sharp blow to the wheel square on (Like crossing a very rough railroad track without unwieghting) Some of Mavics rims, and this is my opinion only, have been anodised in a fashion that makes them kind of brittle. It has been a while but I have seen cxps, open pros,and heliums do the same thing (The old gel280s would break into several pieces)

I too have seen my fair share of rims do the same thing. Not only Mavics but also Suns, Velocitys and others. Given that these rims (CXP 21) are not the highest quality in the Mavic lineup they do not have eyelets or top notch constuction so they are more succeptible to this type of damage to begin with. However that is not to say that Open pros and the like are immune to this damage either. I guess what I am trying to say is that 5000 miles does not seem like a lot, but it really boils down to a persons riding style (some people are far easier on equipment than others) how they care for their equipment, and where they ride to determine the durability of a piece of equipment. I would not let this discourage you from buying another Mavic rim because I honestly believe that they are the best but I would go with one that is eyeleted this time, maybe a CXP 22 (the newer version of your rim). Those can be had for around 40-45 dollars and labor might run you another 30. Good Luck.

-Ryan

I can't tell if you're joking :) So I'm just going to clarify... Of course I'm not riding my road bike offroad over train tracks. It's the train tracks that cross the road that I'm talking about... The train track crossings are in bad repair around here; it's almost like riding offroad! :D

Tim

to clarify, i was joking.... :)

We have no railroad crossings here, but I do have my share of potholes.. Some deep enough to make riders go over the bars. :(

5000 miles is not much.. I have never broken a rim.. well, i may have taco'ed some but no material breaks... I weigh 200lbs BTW.

The cxp21 are pretty decent. no eyelets, but almost all rims I have don't have eyelets. I used to have araya rims, sun rims, columbus, etc. My current one is a rigida(at the same price range as the cxp22's), no eyelets too. But is still holding up.

I just went to check my wheel to see why the brakes were rubbing, and I found that it was broken! See the picture. I've got about 5,000 miles on these wheels.

Anyone have any ideas how this could happen? I rode over some train tracks on my last ride, but I ride across them all the time and have never had any problems. I'm 170 lbs.

Also, any suggestions on a new wheel? A sturdy one preferably :)

Thanks,
Tim

Hey Tnorman, I doubt that anyone (including myself) on this thread is going to be able to tell you why your wheel set failed. But we'll sure have fun thinking up all kind of explanations and theories. Here's mine: #$@%&! Happens. First, when folks indicate that some piece of equipment is "low end stuff", it usually means it doesn't cost as much as some other piece of equipment. And of course if it cost more it's some of the "high end stuff". I've got a number of bikes, three of which are equipped with Mavic rims. All of the rims were built by Wheelsmith Wheels. I don't know if these guys are good or not, but a wheel builder has more influence on the durability of the wheel than does the minute differences in material that you might find from one Mavic rim to the next. The one set of CXP21's that I've got, have been trued one time (it took 10 minutes by a trusted mechanic) and that is after more than 7,500 miles. Yes, I cross railroad tracks too. At this point, I'm kinda surprised my CXP21's haven't failed.

Considering that there can be defects in the materials and in the assembly process of a wheel, rough calculations of a normal process yield would provide that for every 100 wheelsets, two of them would have either a defect in materials or the assembly process (the methodolgy is available if requested).

I was not trying to say Mavics are bad, I have them on five of my bikes(would be six but they did not make 19x3" mod wheels) But I have seen failures with them (and others) just like yours.