^IIRC it uses sintered iron as a friction material, that may be why it isn't riveted. It's a great clutch, the best you can get before going multi-disc. This is the best deal on a REAL DEAL clutch I've seen on TR. Being that it uses a sprung hub, it is VERY street-able and much softer on your drive-train compared to a solid hub disc(like a spec stage 4 & 5) The pressure plate is a completely different design than a factory PP, it will create lots of clamping force without causing a rock hard pedal. The bolt together PP design allows the clutch to be rebuilt cheaply, multiple times. Saving you lots of money in the long run.Bay city clutch will prob rebuild the whole clutch for under $200. Once you get over 400whp, clutches get used up quite quickly. I run a twin disc OS Giken with sprung hubs and it grabs smoothly like a factory clutch but holds as much as you can throw at it.