I just set my TT bike up with shimano 10 speed. All you need to change from 9 speed is 10 speed shifters , 10 speed cassette and a 10 speed chain. The 9 speed rear and front derailleur and cranks work just fine.
andrew
If that is the case then you could use the friction setting instead of the index setting on 9 speed shifters and you wouldn’t need new shifters either. I have 9 speed and 8 speed wheels that I switch between bikes and that is what I do. Just like the “old” days. 
Aloha,
Larry