Bicycle Mechanics - Is a 10 speed chain compatable with a 9 speed crankset

I'm upgrading an older steel framed Trek 400 with a modern drivetrain.

I would like to use a touring triple like this Sugino XD 600 : http://www.velo-orange.com/suoldlotr.html

I'm also considering older 9 speed Ultegra triples.

The bike will have a 10 speed cassette & chain. Will the chain shift properly on a 9 speed crankset?

Michael

Most of the cranksets sold now are 9/10 compatible. I've never had a problem with it. My understanding is that the ring widths have not changed from 9 to 10 speed. It's only the outside width of the chain which was reduced because of the spacing between the rear cogs. The distance between chainrings is the same.

If you have the option, I'd run a 10spd fd. But if you get a killer deal on a 9spd fd, it won't cause issues. I just suspect that the 10spd will be a little bit better.

According to everything I've read, jason is right, the inner diameter of the chain is unchanged and only the outer width has changed. I would go as far as to assume that a nine-speed FD should work fine, as the difference in outer diameter between nine and ten-speed chains is about .6mm (again, according to what I have read).

Most of the cranksets sold now are 9/10 compatible. I've never had a problem with it. My understanding is that the ring widths have not changed from 9 to 10 speed. It's only the outside width of the chain which was reduced because of the spacing between the rear cogs. The distance between chainrings is the same.

If you have the option, I'd run a 10spd fd. But if you get a killer deal on a 9spd fd, it won't cause issues. I just suspect that the 10spd will be a little bit better.

Thanks, I was concerned that the 10 speed chain was too narrow for the 9 speed chainring spacing.

Michael

I've run a 9 speed front derailler with a 10 speed chain and it does work. Shifting is slightly quicker and smoother using a 10 speed front derailler though. This is all on a 9/10 speed compatible Stronglight crank.