Bicycle Mechanics - 9 speed triple on 8 speed cassette?

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digger
01-28-04, 04:52 AM
Hey there!

Is it possible to use a 9 speed triple crank on an 8 speed rear cassette?

The bike in question is a 1998 Shimano 105, triple, 8 speed (standard square slotted crank). New chainrings are needed.

From what I understand you cannot buy a new 8 speed triple with the square slotted crank. I will have to go with a Octalink 9 speed triple with new Octalink BB.

But I don't want to get a new 9 speed cassette, new STI shifters and (possibly) a new rear hub.

Thks
Dgr

P.s. Yes I could just buy new rings but I want to use this square slot triple on another bike I am rebuilding.

demoncyclist
01-28-04, 06:17 AM
Yes, it will work fine.
Bikester
01-28-04, 03:26 PM
Yeh that should be cool!Using a 9 speed crank on an 8 speed cassette and chain is fine its the other way round that causes a problem (an 8 speed crank and a 9 speed chain & cassette).
i know this because i've just done the same thing an had no problems.
It is a bit of a task to find an 8 speed crank, i found a couple on www.wiggle.co.uk but they were only cheep ones.I went for a 9 speed!!

Its something to do with the width of the chain.A 9 speed chain is slightly thiner than an 8 speed so if you use 9 speed chain on a 8 speed crank it doesn't quite sit right.

Hope this makes sense!!