My first twin had horrible street manners, very on/off zero slip, very high engagement point, difficult to drive.
when I sent it back to Spec they found out something was wrong with the pressure plate, I'll let Jeremy say more if need be. But the new clutch, is completely different, perfectly streetable, still same iron discs, but it is much better to drive, and it is slippable to take off, more of a street clutch.
Im putting quite a bit of power through it since the day it went in, I plan on continuing that. Even though my car is not a daily driver, every mile it gets is very hard
