i got a used bontrager crankset from a friend. i replaced the stock shimano crank since it had those crappy stamped chainrings and the bontrager has replaceable rings, and, well, its just better. now the derailler cannot reach the top ring. im affraid ill have to buy a new derailler. any suggestions?

Do you mean the derailleur can't reach the outer ring (i.e., the ring is to far away) or the ring is too big and it is interfering with the derailleur?

Did you swap the bottom bracket when you replaced the crank arms? What length of spindle does the bottom bracket have...it sounds to be too long (if the derailleur can't reach the outer ring).

What does the chainline look like?

yah the ring is too far away. i mean it would be a stretch as far as height goes if the derailler worked, but it would fit.

i did flip the BB. theres not much difference on either side tho so i didnt make much of a difference. i have no idea how long the spindle is.

the chainline is not the best. its slightly slanted in the lowest gear setup, but there are no signs of stress. the chain doesnt derail at inopportune times

Are you using the bottom bracket that came with the bike or the one that was used with the cranks?

The bottom bracket size is likely the problem, but you have to figure out what you have right now. That way you can figure out what size bottom bracket you need.

i didnt get a BB with the crank. so yes its stock. i just thew the "new" crank on.

alright thanks. ill have to look at the bb in a few days when i have time. id do it now but im supposed to be doing homework...

Can you get the BB that was supposed to go with your "new" cranks? That way you can install in and see if it solves your problems.

yah probably. ill give my friend a call soon. i bet he has it, just forgot to give it to me.

do you know ur high and low screws?? change your high screw!

Uh-oh, I was assuming that was already done. If not, then it's a really cheap fix!