My guy is putting the clutch back together. The oily, crappy clutch plates were probably original . They measured .090 thick. The new ones measure .119 thick. He's having trouble determining if he can put the nut on the spring , as the total thickness of all creates an aggregate of about less than a 1/4 in. What are we doing wrong or what is the fix? Thanks in advance for the help... Bob
Hi Bob,there are various ways of rebuilding the clutch.It can be rebuilt as a unit
on the bench and re fitted to the bike,or rebuilt on the bike..Also there are various ways of compressing the spring.there are some members who like to leave out 1 fibre and 1 steel plate.
Check the technical section for some info,also use the search box for other previous replies to similar questions.If all else fails,re ask the original question
cheers Rick
I have used the long saddle bolt (one with the long hexagon bit) and a very large "repair washer" (small hole, big washer) from Wickes to compress the spring from a single spring clutch. It seems to work quite well, though one day I know I will cross thread it. The thread on the saddle bolt is the same as the thread in the clutch centre.
I also run the clutch with or without the extra plates. I cannot notice any change in clutch performance either way.
I have found that new pattern plates are thicker than the size laid down in the standards book for original plates. I always run with one friction and one steel plate removed to give more room for separation in the basket. Much lighter to operate also. I even have the same set up in my BSA/Indian special, which has a much more powerful engine and no slip. Ron
That's not correct..Original plates should be .093" thick...The steel plates are 18 gauge so nominally .048" thick...
Leaving one steel and one fibre plate out of the original clutch plate pile will therefore leave .141" more clearance in the basket for plate separation.
This will not detrimentally affect the clutches performance in terms of its ability to grip sufficiently....
If your pattern fibre plates are .119" thick then you have .208" too much material in the clutch pile..(8 x .026")..Removal of one fibre plate and one steel plate in this case will remove .167" (.119" + .048") and will still leave you with .041" more material than the standard overall clutch pile height...
So there certainly won't be any extra clearance...
Removing two plates from the standard 'pile' is really a 'dodge' to accommodate wear and loss of movement (lift) in the standard clutch...As can be seen it doesn't have the same effect with the thicker than standard plates you have...
Some pattern plates, whilst thicker than the originals are thinner than the ones you have. In that case removal of two plates can leave a clutch plate pile more or less the same height as the standard pile. In that case if the clutch is in fair condition it will still set up OK...but with little, if any, extra clearance...
If you don't have any success, I can supply new fibre plates of the correct thickness...I think I have a couple of sets left from a batch I had made....Ian
It is also important that the clutch spring end faces are parallel. Place the spring on end on a flat surface and place a straight edge over the other end to check this...
The springs frequently 'settle' and become deformed after long periods of use..If the spring is not parallel the clutch pressure plate will not lift squarely, and the space available for plate separation will be reduced...
The best solution to this problem is a new spring...Ian