The title pretty much says it all. This is on my bad-weather bike, so I haven't used it much lately, but this morning was kind of wet and I wanted fenders. It's weird. After several weeks on my nice-weather bike, I am now more annoyed by my bad-weather bike's foibles.

Here are the details: I'm having a problem with the double chainring where the chain is actually dropping between the inner and outer. Seems to happen under medium load (I know I'm not supposed to shift under load) on an uphill when I realize my eyes were bigger than my thigh muscles and my ambition got the better of me. And I need to go from big ring to small ring. I lighten up (so I'm not shifting under the strain of an all-out climb), and release the front derailer to downshift. That's when the chain drops into the gap.

Sometimes I can use the FD to get the chain to climb onto the inner ring. Other times it can get jammed in that gap pretty good.

I've adjusted the derailer a few times.

Right now, I have it set a little "loose" in that it is *capable* of dropping the chain to the outside and inside of the chainring assembly from time to time, on the theory that it will allow me to make a really fast flick of the lever to get it right onto the teeth of the intended chainring instead of the gap between them. This isn't working well.

Tips/trick/adjustments/you'rejustscrewed/stopshiftingunderload?

Is it possible that the chain is too narrow?

The only time that has ever happened to me, it was because I had lost A BUNCH of bolts from my chainwheel assembly:


Trouble by Snak Shak, on Flickr

Are you using a 9 speed chain on an older set of chainrings? While looking up width/spacing specs I found this:

http://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair/Chains/Chain_sizes


Unless you've got a 9 speed cassette I would suggest trying a non-narrow (5/6/7/8 speed) chain.

Thanks. I'm not using a 9-speed chain, but the big chainring is bent a bit--essentially creating the same issue as missing chainring bolt. Will try to flatten it out.