I have an old giant warp D's 2 bike that's about 10 years old. I've maintained it and it still rides good and looks just as good. I wanted to upgrade from the old alivio 8 speed drivetrain to either a new alivio or altus 9 speed ddrivetrain but wasn't sure if the cassette would fit on the freehub on the bike and I didn't want to buy the components and then found out they couldn't fit and then be stuck with useless parts. Could somebody please help the old man stuck in a rut?

  • Why 9 speed? You can still get good 8 speed shifters and its not like the extra speed will help.
    – Batman
    Feb 24, 2015 at 16:55
  • I Actually Want To Go To 9 Speed For The Summer When I Go On Vacation To Pennsylvania Feb 24, 2015 at 17:12
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    I still don't see how the extra cog in the back is going to help -- you're better off picking up a well chosen 8 speed cassette, especially on a commuter.
    – Batman
    Feb 24, 2015 at 18:04
  • A 9s cassette will fit with to a 8s freehub. You also don't really need to replace the crankset although it would improve the culture of shifting.
    – Slovakov
    Feb 24, 2015 at 18:58
  • Hello Batman. I Was Wondering If You Could Help Me ???? Would You Happen To Know If The 9 Speed Shimano Crank And Cassette Might Fit On My Giant Warp DS 2 ??? I Actually Was Going To Overhaul The Entire Drive train If I Could Go Up To A 9 Speed From An 8 Speed. Feb 24, 2015 at 19:43

1 Answer 1


A 9 speed cassette will fit on an 8 speed hub. The extra gear is accommodated using thinner cogs and spacers. You will also need a new shifter as its the shifter that provides the indexing for the gears. If you also increase the range of gears (increase the largest cassette cog), you may need a new rear deraileur.

Its possible to run 8 speed chain rings with a 9 speed chain, but you will get better shifting upgrading the chain-rings. In this case, replacing the entire crank set might be cheaper.

There would be little advantage replacing the deraileurs (especially the front) unless they are worn out.

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