Bent wheel after fall: bad luck or bad built?

raymond82

Hello all,

I recently finally built my first wheelset for my new cyclocross bike out of SRAM X7 disc hubs and DT Swiss X392 rims. I was quite happy with the result but on my first ride on the wheels on a local MTB course I encountered a short but very steep descent, went down scared and haphazardly, fell and tumbled down a bit and after that found the rim badly bent.

The wheel is around 1.5 cm out of true in two opposite places along the rim, I will try to fix it but will probably have to buy a new rim. However although this is probably very hard to judge, is there a chance that the wheel bent during the fall because it wasn't built properly or was it simply bad luck that during the fall too much lateral force was exerted?

I followed Roger Musson's book and overall spoke tensions were pretty much equal but my only doubt was that the spoke tension maybe should have been a bit higher. Before deciding on replacing the rim I would like to be sure I didn't overlook anything in the built process that made the wheel less resistant to such an accident.

Hope you have any thoughts, thanks a lot!

The Rookie

Sounds very like not enough tension.

ugo.santalucia

Tension gives strength tothe wheel, so if you have problems, it's typically the lack of tension, rather than too much of it.

It is very hard to say from here if you damaged the wheel in the fall or the wheel was badly built. Bring it to some reputable shop and they will be able to advise

crankycrank

raymond82 wrote:

is there a chance that the wheel bent during the fall because it wasn't built properly or was it simply bad luck that during the fall too much lateral force was exerted?

Yes and Yes. I think it's impossible for anybody here to give you an answer since none of us have enough info to know if your wheel was built properly or how the bike was crashed. If you do your own rebuild have it checked out by a good wheel builder when done and this will give you a better idea of your building skills.

raymond82

Thanks all for your thoughts, I can see why it's hard to judge without seeing the wheel. I did put extra care in getting the tension a bit higher than it initially was, it's a shame the book is not very clear about what is proper tension.

I didn't want to go to the bike shop because I felt bad showing up with wheels built out of parts ordered online here and there. However I'll buy a new rim at the bikeshop and then I can ask if he's willing to have a look once I rebuilt the wheel. I don't want to give up trying building it myself because I enjoyed the process quite a lot.

crankycrank

raymond82 wrote:

I didn't want to go to the bike shop because I felt bad showing up with wheels built out of parts ordered online here and there.

I think if you just offered to pay them for their labour to do the checking they should be fine with that and it's the price of an education for you. I realize some shops may not think this is worth their time so just go elsewhere if they don't want your business.

raymond82

crankycrank wrote:

raymond82 wrote:

I didn't want to go to the bike shop because I felt bad showing up with wheels built out of parts ordered online here and there.

I think if you just offered to pay them for their labour to do the checking they should be fine with that and it's the price of an education for you. I realize some shops may not think this is worth their time so just go elsewhere if they don't want your business.

That's very true and of course I would not have minded paying. However the owner of the bike shop is the type that often helps without charging which is awesome of course but makes me feel bad if I show up with parts I didn't buy with him. I'll pass by tomorrow to see what he has to say about it.