SS LS1
New Member
Raising engagement speed will decrease clamping load and, with it, grip power......
Whether a lightened rotating assembly and higher initial engagement (a.k.a. stall) speed is a good thing depends on whether you're racing or road riding......
A fraction of a second quicker 0-20mph time will be all but irrelevant, in the "stoplight grand prix." Reduced longevity doesn't play well if you want to get some real miles out of the bike.
...... if your usage plans are for low mileage and short rides...well...maybe a peaky & tweaky race setup is the way to go, if that's what suits your tastes...
To be clear, mine is a skewed perspective...serious road use, i.e. long rides and over a number of years......
Thanks for your input and confirming what I was suspecting that lightening the rotating asembly would reduce clutch clamping load.... So what about increasing the clutch shoe retaining spring pressure (TRX 90 style clutch) to allow stall rpms to be raised before initial clutch engagement? By keeping the shoe weights origional the overall clamping force should remain the same then. Also don't see a way to increase stall speed on the all in one centrifugal clutch assemble without going to less cam actuators which most definitely would alter clamping force.
Much like yourself my perspective is skewed in the complete opposite direction.
Don't personally care about racing, street riding or 0 - 20 mph acceleration at the stoplights as I'm running ATC 70's which will never see street use or high milage obviously. I will keep manual clutch motors in my CT70s as I really don't see any advantage having a hp limited semi auto clutch on the street where it's hard to stall your engine in the first place.
I ride my ATC 70s in fields, hills, sand dunes and along ditch ways much like riding in a half pipe. Often come to an abrupt stop, need tight manuvering and a quick rev to get up short steep incline surfaces without stalling the engine which might cause a backflip problem. Hence the idea of a semi auto clutch and increase stall speed adjustments. (Unique skewed perspective)
I have a nasty ported, cammed and high compression 150cc in another ATC 70 that flies but it is difficult to perform the same manvers with its low mass transmission mounted manual clutch. It is hard to not stall the engine and it doesn't lug very good due to the minimal flywheel effect even with very low gearing for controlled hill climbing.
Either way it sounds like most have not ventured into changes of stall speeds in semi autos so it would be uncharted territory which I don't need to venture into. It also means my 2 in one crankshaft semi auto clutch is limited in options. However a TRX 90 split clutch setup might work nicely by adding a manual clutch lever modification and keep the centrifugal clutch intact. It would live a long semi auto life, eliminate engine stalling and if needed allow one to rev up the stall speed temporarily by slipping the manual clutch plates with a hand lever in tough situations.