Bicycle Mechanics - Expensive bike, nasty dent in rear rim, what should I do?

First of all I love the bikeforum. :thumb:

A few month ago I bought my first expensive road bike. Today I unluckily hit a pothole. When I now apply the rear brake I get a "knocking' or "tapping" noise. I had a hard time to find the dent with the tire on the rim. However, after taking the tire of the nasty dent was much easier to spot. (see pictures)


Now my question: The rim is bend inside on the upper edge, but also a little bit bend to the outside on the inner section of the break section. It is a Ksyrium Equipe rim. I read on the forum that it is possible to repair the dent with a crescent wrench. Hence, I should be able to bend back the upper part of the rim. However, I can't apply the crescent wrench to little dent, which is bend to the outside of the rim, because it is on the lower end of the break section and the inside of the rim is not deep enough. Therefore I thought I can apply a wood hammer to bend in the little dent. Please let me know what you think about my little operation or should I take the rim to my LBS? If so does anyone knows a good LBS in downtown Chicago, and how much would it cost?

Thanks!

Oddly enough I just made a little tool last night to do this sort of job.

Mind you in my case after I straightened out the bead I turned the rim over and noticed that whatever I hit was bad enough to not only dent the rim but also to make the extrusion crush around two of the spoke holes so the rim is dead meat on a stick anyway.

It's easy to make from a little scrap of metal that's 1/4 to 1/2 inch thick using regular hand tools. I'll take a picture or do a quick CAD sketch later tonight for you.

welders vice grips

While these types of fixes can sometimes be made successfully it is much easier on paper than in reality to carry out. I'd be prepared to buy a new rim/wheel but in the meantime try to fix or have it fixed by someone with a good bent rim repair record. You might even consider how bad the 'knocking/tapping noise' is and whether the chance of making it worse is worth the risk and constant reminder of that noise when you brake.

Looks like the edge is bent in and could be carefully bent out with a crescent wrench enough so it is tolerable to ride. Be careful with an aluminum rim not to put too much stress on the area. Al forms stress risers that can severely weaken the area. I have bent rims back into shape and have gotten much added life time. I do keep my eye on any potential cracking in the area. Many LBS owners won't do this because of potential liability issues. If you are commuting on your bike it might be worth getting a cheaper set of wheels and save the good ones for weekend riding...and watch out for those potholes. Good luck.

Time for a new rim. Do YOU want to guarantee that rim that has been bent back when the OP is descending a mountain pass and his front tire blows out?

I've been bending my own rims back like that for over 15 years, and I've never had a problem. In fact, my main MTB front wheel is 13 years old and has about 5 of these repairs on it, with no problems ever.

I use a crescent wrench more often than anything. If I've got the time on my hands, I'll rig the rim surface up flat on my workbench, point a bit of 1x2 pine at the bend, and hit it with a dead-blow hammer, which seems to restore it better than the wrench.

From the pictures, that one looks like it can be straightened out with some hand tools without causing to much stress on the rim. If it were creased .... I would not screw with it.

That wheel is fixable, dont know why some wants you to buy a new rim/wheel. The dent isnt that bad, the good thing is that its fixable. u can use a hammer and a piece of wood and wack it back in place, retrue the best u can done. As makes sence it will be almost perfect... not perfect and u'll save some money from those LBS wolves :P

When i say wack the wheel i really mean it, those rims are super hard, u'll be amazed how hard they are.

There us a tool that can do the job for you also. The good thing is that u have a set of clinchers, with tubular rims u really need to be skilled to fix them...

good luck.

+1 crescent wrench

welders vice grips

I've used them with great results. Some duct tape applied to the jaws prevents leaving marks on aluminum rims.

I much prefer a block of hardwood, like maple, and a C-clamp. Place the block across the braking surface, and fixed portion of the C-clamp on the inward portion of the dent. Slowly draw it back into position. You can also 'cup' the block a little, to ensure the dent comes up even with the surface. With this method, it is easier not to over correct by manhandling.

It is almost impossible to get it perfectly level, but you can easily check by "painting" the braking surface around the repair with some permanent marker, and taking a light swipe with a fine machinists file. You will see if you are high or low.

you may not want to fix the bend. clearly the metal has yielded. no matter what when you unload your wheel there is be some strain. if you bend the wheel again you are yielding it again. now your wheel will may return to zero stain but you've fatigued it significantly. the life of the wheel will be reduced but you can continue riding it. this is all assuming that you have correctly fixed the problem.

I think you can fix it laterally, but what about radially? The bead seat needs to make a perfect circle around the wheel, if it doesn't then I'd replace the rim. If you can bend it back readially true then check the radial true on a truing stand.

Al

Thanks for the postings and advices!

I decided to hand it to a professional, and dropped the rim at a bike shop near my work. (a friend recommended the shop for their great work).

They will be able to bend it back and smooth it out. However there will still be a irregularity.
I'll probably ride it later this afternoon or tomorrow. I'll keep you posted.
Thanks,
karsten

Just got back from the LBS. They said that they started to work on it and realized, it is to soft to bend it all the way back. They recommended to buy a new wheel.

No way ;o) Tomorrow I will buy a crescent wrench, get me a piece of wood, a hammer and try to fix it by myself. Will let you know how the wheel looks after my operation.

Please let me know if anyone knows a thread with pictures of the best way to do it. THX

Get the adjustable wrench if you must but at the same time pickup some metal and make one of these. It's better for doing what you're after since the side pressing on the brakeing face won't be doing so with a hard corner. A layer of tape on the inner side of the longer finger will even prevent scratching.

They should be able to just replace the rim. That wheelset is a little over $400 retail. The rim should be much cheaper.

Thanks BCRider.
I think I'll try to make one of those and try it out.

I bent the dent back with a small crescent wrench and I covered the brake surface with a peace of rubber.
The rim is almost perfect, no more knocking, just a little irregularity but I can live with it. I also bought a hammer and got a flat peace of wood. I didn't use it because I think it is good enough.
Thanks for your help

Just got back from the LBS. They said that they started to work on it and realized, it is to soft to bend it all the way back. They recommended to buy a new wheel.

No way ;o) Tomorrow I will buy a crescent wrench, get me a piece of wood, a hammer and try to fix it by myself. Will let you know how the wheel looks after my operation.

Please let me know if anyone knows a thread with pictures of the best way to do it. THX

Too soft?

That makes no sense. Use a crescent wrench and work it real slowly. Work it from the out side in. Look for cracks as you work the rim. Do it in multiple passes.