CL010 CLUTCH
Another clutch query. I recently had cause to remove my Venom's primary chaincase in order to rectify a pretty serious leak from the chaincase/gearbox joint and decided to replace the clutch components, some of which were clearly past their best. So I replaced the plain and friction plates the chainwheel friction inserts, chainwheel central bearing, spring holder and spring carrier and sleeve gear nut. The bike is fitted with a roller thrust bearing. Assembly with the new components was a straightforward affair, after I had fabricated a couple of tools. (Incidentally, with a new spring carrier and holder, there was no sign at all of the dreaded spring cockling - the holder rotated quite smoothly in the carrier! ) Final adjustment was a first-time affair. I was delighted. I have, however, now completed about 150 miles and was noticing slight signs of drag - nothing too serious. I tried readjusting to rectify this and in spite of many hours at it, appear to have made things a bit worse rather than better. Gear changing is clean, I can select neutral from 1st. or 2nd. at standstill and there is just the slightest sign of drag when the motor is cold. But I cannot engage first gear without quite a clunk accompanied by a very slight lurch forward. If I attempt to adjust the spring carrier by turning it even a few degrees backwards, I simply cause the kickstarter to begin to slip - it really is that sensitive. The only other clues I can give are that without the engine running, the bike can be wheeled quite freely backwards and forward with first gear engaged and the clutch lever held in. Indeed, I can release the lever end by more than a quarter of an inch before resistance increases significantly. So the drag appear to be just initially, when first is engaged. I've always had a bit of a clunk there, but now it's worse. Having tried everything, I'd appreciate any thoughts. Is there a likelihood of things improving as the new parts ( and particularly the chainwheel friction inserts) bed down? - Roger Hinton 28/6/2002
To answer your specific question - yes the clunk may reduce as everything
settles down, loosens up and gets nicely oily. However I have to confess it
still happens on most of my bikes! The only ones that it doesn't seem to happen
on are really old and nearly worn-out clutches, or those which use only the
club's plates.
I think what must be happening is that the plates are sticking together (and/or
the clutch chainwheel is binding a little on the sleeve gear).
Assuming the clutch is fine in every other respect, when you withdraw the clutch
with the bike in gear the plates are made to un-stick from each other by the
different engine and road speeds. Even with road speed zero, if the engine is
turning and you are in gear, every plate must separate from its neighbour or you
would move forward! So with the plates separated you can slide easily out of
first or second and into neutral.
But when you are in neutral, even if just one pair sticks, there is going to be
a crunch since nothing will separate them until you force the dogs into
engagement.
Of course the big difference between going into neutral and coming out of it is
that it is much easier to disengage dogs than engage them! So if it is just
slight drag from new components bedding in, or a non-flat or sticky component
somewhere, then you may notice it only when moving out of neutral. - TW
28/6/2002
It's reassuring to learn that my machine is not unique in this respect. I must have tried every combination of adjustments during perhaps 30 attempts! So it will either settle down, or I will adjust to it! - RH 29/6/2002