I recently serviced my Agility's clutch assembly and basically just removed all dust, and re- greased the needle bearing. I passed some comments regarding the results, and another forum member mentioned that he also serviced his scooter's clutch assembly, and his service included sanding the clutch shoes.
I didn't sand the shoes during my own service, and I started thinking about the other owner's comment. Since my own service I experienced a definite improvement, but I started thinking about the fact that the engine Rpm's on my scooter seemed to be quite high before the clutch engages.
So during this weekend I decided to strip the clutch assembling again, to clean and sanding the clutch shoes.
When I had a proper look at the shoes, I immediately realized that I actually have a problem. I realized that the clutch's outer shoes are actually glued to a backing compound, and the outer pads on my scooter's shoes are almost on it's last legs. By measuring the outer pads itself, I noticed the are only about 0,26mm of the pads are left - before the clutch will actually start engaging on the backing compound.
I have no idea how thick the shoes on new shoes actually are, but realized that the high Rpms needed on my scooter's engine needed to get the scooter going probably had something to do with the fact that the thickness of the shoes on my scooter's clutch shoes would probably be a lot thinner than the thickness of new clutch shoes.
I realized that the springs on my scooter's clutch actually needed more Rpm's from the engine, to allow more travel on the shoes for proper clutch engagement.
So I decided to order new clutch components from elsewhere, and concocted a plan to get the scooter's clutch engaged at lower engine Rpm's while I's still waiting for the new components.
In short - I decided to ad more weight to only three of the variator Rollers . So I just removed the center metal bushes from three of the rollers, threaded the center holes of the bushes with a 8 mm tap, and cut 3 pieces from an eight mm. threaded rod to be screwed into the holes at the roller bushes.
Before installation I used a digital scale to make sure that the 3 modified roller's weight are exactly the same. This was quite easy - I just used a grinder to remove some steel from the 3 bits of threaded rod until the weights were the same.
According to my digital scale the final weight of the 3 modified rollers ended up at 18 gram each, while the weight on standard rollers are 15 gram.
I also cut slots at the 3 short pieces of 8mm rod, for easier installation. During installation I used some Locktite just to make sure the inserts will not come loose by itself. The 3 modified rollers and the 3 standard rollers have been installed in a staggered way at the Variator.
The shoes itself have just been cleaned with a soft steel brush.
When testing the scooter's performance afterwards, some of the results were exactly as expected. The clutch now engages at lower engine Rpms during take off, and the engine Rpm's definitely seem to be slightly lower at any given speed.
I was quite surprised about the scooter's general performance though - I couldn't sense any loss of power, even while I was riding uphill, or riding upwards at our steep driveway.
I still need to see whether the 3 roller inserts need to be removed when the new shoes arrive. For the time being I am very happy with the results.
Some pictures can be seen below.
