Chain comes off the inner chainring

[jasonsankar]

Hi- I just bought a used bike with a fairly new ultegra group on it. The bike is great, except that the chain comes off the inner chain ring under load.

It comes off when I am in the large cog on the cassette and the small chainring, usually when I am climbing a hill. It does not come off when shifting gears, only when I am really pushing the pedals to get over the hill.

I have adjusted the front derailler so that it almost rubs the chain on the inside when in the small chainring, and so that the cage is one millimeter above the large chainring.

Any suggestions? Jason

 

[Salsa Rider]

Hi- I just bought a used bike with a fairly new ultegra group on it. The bike is great, except that the chain comes off the inner chain ring under load.

It comes off when I am in the large cog on the cassette and the small chainring, usually when I am climbing a hill. It does not come off when shifting gears, only when I am really pushing the pedals to get over the hill.

I have adjusted the front derailler so that it almost rubs the chain on the inside when in the small chainring, and so that the cage is one millimeter above the large chainring.

Any suggestions? Jason

I noticed that you said "fairly new" ultegra group set. Is it possible that either your chain rings or BB spindle is just slight out of align, or bent?