Bicycle Mechanics - Throwing the chain

I have been working on a Schwinn LeTour for over 15 years, and recently decided to invest a small amount on the drive train. I got a new freewheel, chain, and replaced the crankset (I had an old one off another ten-speed which had not been used too much).

The reason for the change is that the chain was skipping, and at first I thought it was the freewheel (which was worn and had two bent cogs). After it was replaced, the chain still skipped, so I replaced the crankset.

This works well, but when I get to the smaller cogs, and go to shift to the larger chainring, many times it will throw the chain outward onto the crank arm, leaving me temporarily stranded.

Could it be that my rear derailleur is weak, and not able to hold the chain tension to keep it from coming off? It is quite old, fairly cheap, and is not original (Shimano SIS).

Also, there is a protective ring on the old, original large chainring. I had thought this was only for protecting clothing, but could it be keeping the chain from flying off?

Your help would be much appreciated.

John

It sounds like a limit screw adjustment. Try turning the H screw on the front der. in 1/4 turn increments and shift it unitl this does not happen but it still shiifts to the outer ring.

I did that, and it got better, but still is thrown. I'll try again, but I think I'm at the inner limit of the front deraileur.

John

Is there tension from the rear derailluer? would removing a few links from the chain help?

Try bending the outer plate of the cage, so the lower edge is (very) slightly inboard of the top edge.

Ride a Little
Pat

Thanks all for the input. I may have solved it by adjusting again, and by the bending of the lower edge. I'll try it out soon.

John