[daniell]

Does anyone have any experience with the following. I am thinking of this setup for my mountain bike?

All 8 speed except the cranset which will be 9 speed.
Will the shifting in the front suffer?

Thanks

 

[Andy M-S]

Should work fine. IMO/E, you might want to try a 9-speed chain as well, but that's optional.

 

[daniell]

Crank differences

How does an 8 speed crank differ from a 9 speed crank? Are the chainrings narrower, or is the spacing between them less?
Also, when comparing a 9 speed chain with an 8 speed chain, is there a difference in the width where the chain fits inside?

Thanks

 

[Lt.]

I believe the spacing up front is fine but an 8-speed chain will not work with a 9-speed cassette.

Check mtbr.com for some useful info.

 

[Mark McM]

8spd and 9spd differences

How does an 8 speed crank differ from a 9 speed crank? Are the chainrings narrower, or is the spacing between them less?
Also, when comparing a 9 speed chain with an 8 speed chain, is there a difference in the width where the chain fits inside?

For both Shimano and Campagnolo, the cranks themselves are identical between 8spd and 9spd. However, Shimano 9spd chainrings are offset slightly, so that the chainrings are slightly closer to each other (there is no difference between Campagnolo 8spd and 9spd chainrings). An 8spd chainring generally works okay on a Shimano 9spd crank, although there is a slight increased chance that the chain may initially ride on top of the inner ring when shifting down.

The primary difference between 8spd and 9spd chains is their outer width. 8spd and 9spd sprockets are nearly the same in width (1.8mm vs. 1.78mm for Shimano, 1.9mm vs. 1.75mm for campagnolo), so 8spd and 9spd chains are also nearly identical in inner width. Most 9spd chains work just fine on 8spd cassettes.

 

[Anti-gravity]

My experience

How does an 8 speed crank differ from a 9 speed crank? Are the chainrings narrower, or is the spacing between them less?
Also, when comparing a 9 speed chain with an 8 speed chain, is there a difference in the width where the chain fits inside?

Thanks

IME with using a 9-speed crankset (Deore) w/ an 8s chain, I had massive problems with chainsuck, even with the drivetrain cleaned/lubed and the chainrings relatively new. It was on a Klein Attitude hardtail, which has pretty short chainstays, so it's possible that that combination led to the problems I had. When I put a 9s chain on (using an 8s cassette), the problem went away. Shifting was pretty much the same with the 9s chain on the 8s speed cassette.

This was back when I defiantly resisted switching to 9s, believing that 8s was more durable. I finally gave up on that notion and use only 9s offroad. Durability doesn't seem to be any different than 8s, so I'm convinced the supposed durability of 8s over 9s is largely a myth.

You really should ask questions like this on MTBR, they'll have better answers/experiences to share .