I've got a Yoyo slipper, absolutely love it, but my riding style leads to me spending lots of money on fibers. A brand new clutch stack just nets me 1.22mm of preload as per Yoyodyne's measurement system. 8 hours on the motor eats .4mm of stack height. When it finally starts slipping under power (Around the 18 hour mark) the fibers and steels still measure as solidly fresh according to the manual. I know you can get alternate thickness steels for Ducatis for example to dial in the stack height as the clutch pack wears. I haven't found anyone that will custom make me said thicker shim steels for my FZR, but I did get to thinking... (Nothing good ever comes from this BTW). Why couldn't I send a few steels off to one of the brake rotor straightening shops that have magnetic rotor mills to have them grind me some thin shims? .5mm, 1mm, enough so that I can rehab a 'bad' stack back into usable stack height / preload range by doubling up an inner steel. On a similar topic, any YZ85/125 racers looking for discount clutch fiber sets with minimal wear?
The more I stew on this, the more I keep thinking warping would be the potential problem for thinner than stock steels? They would only be seeing heat on one side, but I assume even backed by a normal thickness steel they'll be more warp prone?
0.5mm. 1mm, that is pretty thin for the diameter. I wouldn't be so worried about warping, at that thickness they couldn't offer much tension in the stack. I would be more worried about them deciding to randomly break and trying to find a quick way out. Might be better off just having some extra thick plates cut.
Try "custom laser metal cutting" or "custom waterjet cutting" on that advertising site, heck whats the name... Oh yeah. Google. There is a pretty good industry around one-offs when you provide the design, and designing a metal clutch plate would take someone with Solidworks about 10 minutes. Maybe as a student project at a local tech school....
eMachine Shop, Big Blue Saw, etc ... Get a set of +0.5mm plates cut. Start a fresh set of frictions with standard steel plates. Every 10 hours of running, swap out 1 steel for a thicker plate. Once you've replaced all the steels with thicker items, inspect your frictions. Are they still in spec? If so, order a set of +1.0mm plates, and repeat the cycle!
suprised the FZR doesnt share a common clutch plate/fiber size with other models?. Maybe EBC has a cross reference chart?
I started reading your post again. 18 hours on an FZR400 clutch? Is that 10-12 weekends? That's crazy stuff.
About, I wouldn't be so ticked if it wasn't for the fact that you can't actually measure the wear on the individual fibers before the stack is no good.
