WH-KX10 9 speed compatible (shimano freehubon campy wheels)
 

I want to get some wheels built up with '08 Record hubs for my training bike which is still running 9 speeed Dura-ace. I want to know if the WH-KX10 is compatible with 9 speed Shimano cassettes.

I've had a lot of 'yeah, should be' and 'Don't think so' but am yet to get a definitive answer. Has anybody actually tried it?

All 10 speed Shimano cassettes will work on all Shimano-splined 9-speed freehub bodies with a 1mm spacer.

Thanks, but please read the question.

Read my answer.

I want to run a 9 speed cassette on the WH-KX10 free hub body, which I have seen in a few places say "10 speed only"

The 10 speed Dura-ace free hub body will ONLY take 10 speed cassettes as the splines are higher than the 9 speed free hub body and the 10speed cassettes have been modified accordingly. I want to know if the WH-KX10 has similarly been redsigned, making it impossible to use 9 speed cassettes on it.

You answer does not address this.

The WH-KX10 is 10spd only. The WH-KX2 is the 8/9 spd Shimano freehub body designated for Chorus (I think because it has a steel body and Record freehub bodies are alloy).