Is .75 to 1mm of clearance between the teeth on the small chainring and the chainstay enough? Almost finished building up my bike and this is what I am looking at. The frame is pretty stiff (titanium Seven Axiom) and installing Chorus group (standard double). The drivetrain shifts fine and lines up great. Thanks for any input.

A bottom bracket spacer is usually a clean and easy installation. You could move your crankset out 1 - 2 mm for more clearance.

Al

Thanks. I had someone today tell me that down to .50 mm of clearance was OK. I have trouble believing that though.

Such small clearance might cause some rubbing once you're on the bike cranking away....

How much clearance is between the chain and chainstay when the chain is in the small chainring? Sounds like there wouldn't even be room for the chain if the small chainring is laready that close to the chainstay.

chain hopefully wouldn't be touching the chainring at that position.

I doubt it'll be a problem - even with flex, the whole bike flexes, not just a section. i.e. you'd have to flex the frame more than 1mm to make a 1mm difference in chainring position.

I'd try it, if the flex turns out to be a problem then add a spacer. As long as the ring has free travel and your chainline is good it's fine.

Thanks for all the replies. I think I will leave it for now and see how it works out. The guy who told me that .50 mm was enough said the same thing--everything will flex together, and the way things will flex will likely not push the chainring into the chainstay in that position--basically the bike won't be flexing at that kind of angle as to push it into the chainstay. Anyway, that's where I'm at and I'll let you know how things work out. Again, appreciate the replies.