How can I confirm the forks aren't bent?

[maniac1886]

So a buddy of mine has a cbr. he laid it down, and based on the fact that the top of the gas tank was caved in, I'm assuming it went end over end at least once. I am in the process fixing all the broken stuff and getting it ready to roll again. It idles, runs, and seems to drive good. I just so happen to have another F2 in my garage right now for a carb clean so I turned the handlebars all the way in each direction, and compared it to the undamaged F2 and they seemed fine. I bounced the front end, the forks seem to compress and retract just fine. I took it around the block yesterday, got up to about 30 mph. It didnt seem to pull at all. I did feel a few minor wobbles but i couldnt tell if it was the bike or the road. The wobble felt very inconsistent. It did it once when stopping at a stop sign, but it didnt happen at the next stop sign one block away. One time i felt it when i hit the throttle but the next time i blipped the throttle and it didnt wobble. I checked the tire and it has full pressure so I assume that the rim is not bent. I was just hoping for some suggestions in any other tests that I can do so that I can be 100% sure that this bike is in tip top before I give it back to him.

Thanks guys.

[rschlegel]

As far as the forks go, you could remove the fork legs from the triples and check them with a straight edge. If they end up ok, maybe a fork brace or something got tweaked out of position but not enough to easily see. Putting it back together could re position things correctly. I had a slight wobble with hands off bars and found that the bolts holding my fork brace were loose and one was gone.

[Kreylyn]

Yes, the some of the best ways is a known good straight edge, or roll the tubes on a flat surface and look for the wobble.

Sit the front wheel up so you can spin it freely. Set a block beside it, or something you can put a pencil on. Set the eraser tip in a fix position 1mm from the rim lip edge. Same place one would put the rim tape. Spin the wheel. If it hit the eraser, or you see it move away form the eraser... then the wheel is bent. How much run out your willing to deal with is up to you, but generally more than 1mm is probably not good.

Krey

[maniac1886]

thanks for the wheel tip, ill do that for sure. as for the forks, I was hopig there was something I could do without pulling them all the way off. what if I pulled the tire and loosened the tree clamps and turned them while still on the bike. I assume if they were bent the part of the fork that mounts to the wheel would move in a circular fashion as they spin or the tubes would bind in the trees depending on where the potential bend is. I got an f3 front end on donate but I was hopin not to need it but in all honesty if I can't test them without disassembling them id probably sooner just say eff it and swap em out

[maniac1886]

yah thats kind of what i was afraid of. Probably just going to swap it out for the other front end. Better safe than sorry.