@McChicken I have no idea how many RPM the freewheel can take - I'm guessing its somewhere near the redline since it is supposed to last.
On another note, I'm the OP who originally asked if the SBP shift kit is worth the cost. After receiving mine in the mail a week ago and finishing it last night and going for a ride, I can say that the answer is a definitive YES! You have so much torque in a low gear, and when you shift into a higher gear you can cruise in the 30's easily. The engine vibrates a lot less because in high gear its running a lot lower RPMs. All in all, hats off to SBP for creating such a wonderful product!