free bump... the yoyo slippers are phenominal, i've had one in my 51 for about 15000 miles and have had only good luck with it. the nice thing with the yoyo unlike most other brands is that it doesn't use spider springs, it uses 6 coil springs that go over the posts (you can see them held in with 6 little surclips). not only does this mean you won't get the inevitable failed spider springs but you can also easily tune how much slip you get by removing springs in pairs. (plus they hold all the ball bearings in while the clutch is loose, no more dropping them all over the place).