Hi Ren,
I have rebuilt almost 100 clutches [still have 7 rebuilt hubs in stock]. Here are my findings during the rebuild process. Several had the hub cut undersize and the factory installed sleeve [soft] actually pulled off [amazing!], some had the O.D. of the sleeve [soft] cut under size, some had the I.D. of the outer hub cut un-even, and some had the pins that mount the shoes work loose. The loose sleeves, loose one way bearing and the undersize sleeve presented the problem of the clutch slipping when trying to start the bike. The odd size [uneven] hub caused the clutch to slip and wouldn't allow the shoes to completely engage. The loose pins simply made the clutch spin with no forward movement.
I don't and never have understood why they continued to replace defective clutches with identical parts that would also fail, guess it just bought more time until the warranty ran out.
Of the almost 100 rebuilt clutch hubs I sent out, none have contacted me with more problems. The only feedback has been a few trying the clutch for the first time and the shoes haven't seated in yet [slippage until the shoes mate with the hub]. I have been using the hub with the harder [quality] sleeve for over 2 years on all my bikes and no serious clutch problems, except for cleaning the glaze off the shoes when I stressed the assembly [wide open going up steep hills, or drag racing].
I have passed on the information to many and most modified their clutches with great results [one refused to accept the solution and insisted they were too smart, and now re-designed the unit with similar poor results]. Some of the problems transferred to the new changed clutch unit, including loose sleeves, soft bearing races and a couple of new problems to add more drama. The latest offering presented a slipping one-way bearing [loose inside the aluminum housing when hot], grease leaking onto the shoes because of no grease seals, and the caged bearings loose in the housing], and still rides on the soft bearing race.
One of my modified clutches has over 3000 miles [very hard miles] and looks new inside, guess using the quality hardened sleeve produced great results. The sleeve is 38.5 MM long, I.D. of 25 MM, and 30 MM O.D. with a Rockwell hardness factor of 58. The sleeves are easy to find and most bearing companies can supply them in a short period of time [7 to 10 days]. The average machine shop will charge about $100 to install the sleeve, and the sleeve usually costs between $25.00 to $40.00 [depending on company and shipping charges]. I charged most $100.00 exchange to rebuild the hub, a small price to pay for "piece of mind".
Hope this information is helpful in making your Whizzer durable and more fun.
Quenton
