Front Dérailleur Problems

[kc9qyb]

I have an old 1983 BCA road bike that I am being loaned. Today I decided to shift down to the smaller spokes in the front and suddenly i hear that the chain is rubbing against something so I go into a park and try and fix it. I tried to shift back up to the larger spokes and the chain came completely off of the spokes and onto the pedal bar. I tried to get it back on which i did and I moved the shifting lever up a little bit but I still got that rubbing sound and it had increased in volume. I spent about an hour trying to fix it but it would just not stop rubbing. Then a fellow biker came to lend me a hand and he said that the dérailleur appeared to be bent. I took it home and tried to fix it and i got the front dérailleur aligned perfectly but now I have ran into a new problem. When the chain is on the smallest spokes on the back the chain rubs against the frame in the back where it attaches to the wheel. How do I go about fixing this? Is my front dérailleur bent?

[Jordan300]

Maybe your chain is too long. If you're putting it on both smallest cogs, which would be the farthest left on the front and right on the back, you might have some issues if the chain is too long.

[DaveM]

If your chain hits the frame when on the smallest cog in the back there is either a spacer missing on the rear axle or the wrong size freewheel was put on. I can't think of any way this would happen suddenly unless the freewheel is actually breaking apart or something. Are you sure this wasn't happening before?

The hack to fix this is often to put the wheel on with an extra washer between the frame and the right end of the axle. But that is not a good long term fix.