OK, I finaly got around to mounting a grinding wheel in place of the knurled steel roller. I used a diamond stone dresser and a jig and sidegrinder to dress the 4" wheel down to 3.5" dia to match the steel roller dia.
I had trouble trying to make a stepped threaded shaft for it on my dinky lathe, and the cold rolled steel is way too hard to thread with a die nut, so I devised non lathed threaded stepped shaft.
I simply used a length of 5/8 allthread rod woth the grinding wheel screwed on to the appropiate place and locked with a locknut.
I then slipped sections of 3/4 steel tube from hdw store, leaving enough threads showing on each end for jam nuts. I had previously pressed the pillow bearings to their appropiate places on the tubing, using a large vice and deep sockets,pipe nipples ect. Then assembled everything and tightend the jam nuts on each end of the shaft.
To lock the pullies without a keyway, I drilled into the shaft,(tubing /allthread assy), holes about 3/8" deep, with a bit 1/64 smaller in dia. than the long 5/16 setscrews I used, to give them interference fit. This worked good on the original solid shaft with the steel roller, got almost 600 miles on it with no probs other than the knurls aren't as agressive as they were when new. Slips a lot when wet now.
I haven't tried the stone roller in the wet yet, but it grabs dry, way better than the steel roller with much less pressure against the tire. Less pressure equals less rollong resistance and more speed and efficency.
Barely rolling, with the roller adjusted to 1/4" tire deflection,I can rev the engine and pop the clutch and jerk the bars lightly, and do a 1 foot wheelie!
I think I could jam the roller down to abt 3/8" and prolly pull a full walking wheelie!
I can now use full throttle accelleration in first gear, with no slipping . With the steel roller, I had to feather the 99cc's throttle to keep the engine from racing when accelerating in first gear.
Hey, it might rain here today, might get a chance to try out wet performance.
