Spacers for 10/11 speed hub to fit 9 speed cassette

[bedcurt]

My wife bought some new wheels(http://www.wiggle.co.uk/shimano-rs11-alloy-clincher-wheelset/) for Christmas however i'm trying to workout whether I need a spacer to fit a 9-speed cassette.

I've seen many forums and the advice says I don't need one others say I do, can anyone help ?

 

[cyberknight]

1.85 mm
http://www.slowtwitch.com/Tech/Cassette_How-To_-_Part_2_3257.html

 

[si_c]

One should have come with the wheels for 8/9/10 speed cassettes as they use the same spacer.

 

[bedcurt]

thanks all !