Shimano 9/10 spd cassette questions

Yep, your 9 speed cassette should go on just fine without any hassles or washers/spacers.

Generally speaking, this is the case for any 8/9/10 speed Shimano cassette, with a few minor exceptions.

10 speed cassettes have a little recess at the back of their spider. When using a conventional 8/9 speed hub you you need to put in a tiny little spacer washer to fill in this gap. These come with the cassette, though.

Also, new Shimano Dura-Ace hubs and wheelsets have an aluminium freehub body with a deeper spline pattern. Only 10 speed cassettes can fit on these. (This design change prevents the 'gouging' marks on an aluminium freehub body that can be left by a steel cassette.)

jcbarnett said:

I have a 9 spd Dura-Ace cassette that I'm going to be removing from my Bontrager Race X Lite wheel and installing on my new Bontrager X Lite Carbon Aero wheel. The Aero wheel will accept 8/9/10 spd Shimano cassettes. My question are: are all 105/Ultegra/Dura-Ace cassettes interchangeable? Will I need a special spacer/washer with the Dura-Ace 9 spd cassette on the Aero wheel?? Many THANKS for the assistance.

Yes, they are interchangeable for those wheels. You do NOT need the spacer for 9s, only with 10s. The lack of interchangeability is that 9s cassettes will not fit on dura-ace 10s hubs.

I don't know if I did something wrong but when i installed my nine speed cassette on my new Aksium wheels I had to use the spacer. I asked my LBS about this and they said that it was fine. They said they always try it first with the spacer. Maybe Mavic does something weird with their hubs. I know I didn't have to adjust the rear derailleur at all and the chain line is correct.