CJB91

I will shortly be getting a cycleops fluid 2 turbo trainer. I have just seen that there is an adapter available and it says you need it for bikes with 20/24 wheels. I have a cannondale caad8, and on the tyres it says 700/23. Does anybody know if I will need the adapter? Some websites make it look like you only need it if you have 20 or 24 wheels, while some make it look like if your wheels fall between these sizes. Here is a link for the adapter- http://www.wiggle.co.uk/cycleops-202...wheel-adapter/

Thankyou in advance!!!