uluchay

I just had an accident where I tried to cut a roundabout (no traffic) and fashionably failed to do so. It is on my daily route back from work and even I was surprised because I never had problems with this turn before. Maybe it was just some lack of concentration (kids, do not attempt to cut roundabouts!). I slammed the brakes when I realised I was gonna crash. I cannot estimate my actual speed when I hit the kerb but I guess it was slow enough because I was able to put my right foot on the kerb just after the hit without falling and my left foot didn't even unclick. However, my front rim, tyre and air chamber were not lucky enough and the latter two banged at instant. I have a spare tyre and air chamber but I don't know if I should worry about the rim. If it was a city bike or my old crappy mtb I wouldn't even care but I achieve speeds of 60+ kph and I use front brake quite a lot.

Here are some pics:



Notice that the blow is NOT on the impact side and I really can't determine the crash point. The left side appears to have more damage than the impact side.

And a video:


It swerves a little bit to the left but I'm not sure if it's something that I should get checked.

What I'm asking is: should I install the spare tyre or do I have to pay a visit to my LBS?

fietsbob

You need the bike serviced .. take it to Your LBS and have the wheels trued and tensioned ..

SteelCan

Oops. similar to what was said above with a few additional comments.
Remove the "warped" tire which is likely increasing the visual "swerve".
You also have a few scuffs on the rim edge. Lightly file/sand them down. That will not cause a problem with tire bead.
I suspect it's not as bad as you think HOWEVER rim should still be trued. At a minimum, a handful of spokes should be relaxed and re-tensioned. You could do it yourself (loads of info here) using the brake pads as the gauge or take it to your LBS.

uluchay

Thanks a lot for the answers. Do you know how I can sand it? I mean the grade of paper I should use.

mrrabbit 

A very fine jewelers file to remove burs...400 grit metal wet sanding paper to take care of the final finish. Try to work in the direction of the rim circumference.

Don't try to be perfect - long as its semi-smooth - brake wear over the next few hundreds miles with take care of the rest.

=8-)

FBinNY 

Don't use sandpaper, use a file. A half-mill medium will leave a smooth surface, free of the lines a normal diamond pattern can leave. Hold the file at an angle to the rim (without tire) and pull the wheel past the file, in sort of a lathe action, working in long arcs.

This is about 5 minutes work, and when finished a bit of touch up truing, and this wheel will be 99% as good as new. OTOH, the tire looks like it's toast.

BTW- quick non=mechanical qution. What do you mean "cut a roundabout"?

zukahn1 

Yes the rim does appear to have some potential issues yet they more than likely can be trued out by a good mechanic. You defenitely should have the wheel trued and evaluated at LBS. It just isn't possible to a evaluate a rim from a couple pics it is something a better mechanic needs to do in person. I have seen rims that looked awfull a inch out of round that have trued up fine and others that looked near perfect that where none truable and unsafe to ride.

gsa103

Aside from simple truing the only major issues would be a significant D-shape in the rim which is basically impossible to fix.

The other difficult fix is if the rim walls are bent outward. If they're bent outward the brakes will consistently grab in the that spot and you'll flat-spot tires quickly. I did that to a mountain bike in college. After you get the wheel trued up, apply the brakes lightly and see if they consistently grab in the same spot. A vise may be able to fix it, it may not.

uluchay

"cutting" is when you approach it from the right (outer) lane, sweep past the middle section (inner lane) and continue on the outer lane as you leave to have a more straight line. It is illegal to cut and you should respect your lane at all times. Cyclist should stick to the outer lane. It is a motor racing term and I don't really know if it has an equivalent in cycling.




As far as I checked, the rim looks perfectly round. No vertical movement that I can tell.

I read somewhere that 2mm horizontal movement is the threshold for truing and mine doesn't look like it moves that much but I think I will consult a local Trek dealer to be sure.

Thanks again.