Center force is no better or worst and any other clutch. The problem is the weights on the pressure plate and running an organic disc. Over 3,000 rpms I couldnot shift the car PERIOD. This was on a new 6 spd richmond. Richmond said that it was possible of too much torque for the trans. I brought a G-Force 5 spd and got the same problem. I called Centerforce 5 times and talked to tech guys tell me it was everything both the pressure plate weights. I asked 3 different people to EXPLAIN how the sliding weights work. Was told the higher the RPMs on the motor the farther the weight expand out to the edge of the pressure plate and add pressure to the fingers of the plate to add holding pressure on the disc. I said at high rpms how does it shift?? He said that there is no different between idle and 6,000 rpms. This is a bunch of CRAP. $7.000.00 dollars later I found that the weights where causing the problem. I removed the weight and could shift at 6,000 rpms without any problems. ERA removes the weights before installing when they sell turn key cars. ERA also redesigned their clutch fork to work better too.
I have run Zoom, Hayes, Schaffer, and the list goes on. If the clutch is setup with the correct air gap of .035"-.055" You should not have any problem with even a stock clutch. A clutch pedal stop is also important to not cause overbending of the pressure plate forks or diapham of the pressure plate. Biggest thing that is missed on is the correct pressure plate holding pressure for the clutch. 2,400-3,200 pressure plates are used. This needs to be matched up to the car or truck amd the application of the car or truck.
Last thing is breakin, first 500 miles for ANY clutch is needed. Alot of guys put a new clutch in and beat the crap out of it and if it slips, it's a bad clutch and not a poor breakin period. Some people call them heat cycles.
I like the soft pedal and feel on the street twin. I know that there is no slipping any more too. 2 10.5" discs against 1 11' or 12", who has more holding surface?
Rick L.