Fitting a 9 speed cassette on Fulcrum 5s

Tomonabike

I have a pair of Fulcrum 5 evos that I had a 10 speed ultegra cassette on, I now want to swap it to a 9 speed cassette (also ultegra).

Do I need to put a spacer between the hub and the largest (25 tooth) cog or not?

thanks

Tom

redddraggon

Nope