Hi Folks, just thought I'd throw this one out. I decided to check the little blighters tonight and although they were cleaned with Brake Disc Cleaner, plus a suitable sized nut/bolt/washer combination,they will still only turn with the assistance of a socket. Is this normal or should they now be free enough to be turned by hand? Answers on a postcard please
The discs on the dvt are semi floating which I think means the bobbins a a fairly decent resistance fit, I'd expect them to be pretty tight.
+1 on this, I thought semi, you dolt get the really rattley noise you get like the old SPS fully floating discs
I used a drill on the bolts and kept spraying Cillit Bang degreaser in there till the muck stopped coming out and I could get an audible click when moving each bobbin by hand. Maybe this was overdoing it but the brakes work much better now.
As far as i am aware they should be semi floating and move with some effort. SPS discs are very "loose" and you can hear them rattle as soon as you move the bike, they are designed to be like that and were one of the so called selling points of the SPS range when they were available.
They aren't supposed to be spun, at all, and with degreaser makes it even worse. Where did this urban myth come from?
On fully floating discs, the bobbins will be loose enough to turn by hand (and the rotors will rattle on the carriers). These are identifiable by having circlips on the inboard side of the bobbins. Most discs are semi floating and although the bobbins are still a loose fit, they are held tight by dished, spring washers. These have no circlips but instead the bobbins are "riveted" permanently in place. The tension from the spring washers will prevent them turning easily by hand.
On fully floating discs, the bobbins will be loose enough to turn by hand (and the rotors will rattle on the carriers). These are identifiable by having circlips on the inboard side of the bobbins. Most discs are semi floating and although the bobbins are still a loose fit, they are held tight by dished, spring washers. These have no circlips but instead the bobbins are "riveted" permanently in place. The tension from the spring washers will prevent them turning easily by hand.
Well I had no benchmark to work to so just set about freeing them up. Maybe they are now rather more floating than semi floating but they work much better than they did when fully seized, so I'm happy.
