I’ve got a Giant Defy with TRP Spyre disc brakes but want to change the standard steel 160mm rotors that came fitted.
I fancy fitting Hope Race X2 floating rotors but wondered if it would be better going 140mm instead. The higher up models with full Shimano hydro brakes come with 140mm rotors and my frame and forks both have 160 adaptors so will definitely fit the smaller rotors.

I might go full hydro at some point (funds allowing) so can keep the same rotors but don’t want to possibly be under braked with the TRP Spyres with 140mm rotors being less powerful than the Shimanos.

Any ideas?