[singleminded]

Hi Tom..Thanks for that. I had an idea that the material should be fairly thin but needed another opinion before I started on this job, I hate wasting my money needlessly..I machined the 2 inner plates to 7/32" 5.5mm and just skimmed the outer plate to get as near the 23/64" 9.128mm as possible, this left the stack of plates a little too near the top of the clutch centre for my liking..The material fitted has a random weave pattern and is 3mm thick. I left the rear of the chainwhell at the full thickness and reduced the inside to 1/16" or 1.5mm(near enough) and this allowed the plates to fully engage the centre with enough allowance for clutch lift so that the top plain plate will not pop out. the advantage of having such a thick material to start with is that if the plates were not perfectly flat that they would be after finishing, my friction plates are now less than a thou or two parallel..John

[Tom Snow]

Hi John,

In the course of re-commissioning a Longstroke with a six spring clutch I found that the plates and basket had been re-lined with bonded friction material. The material was so thick that the outer presser plate was outside the clutch basket as a result of excessive friction material thickness. I inspected several other plates with bonded friction material from other bikes I have with known good performance and the average thickness of the friction material was 0.050"; I machines the friction material back to approximately this dimension on the plates and the basket and it was then possible to build the clutch with all of the plates being contained within the basket. Subsequent road testing proved that sufficient grip was available with minimum spring pressure and the clutch cleared allowing the gears to be selected from rest without gear crashing.

Hope this helps,

Best regards,

Tom.   

[singleminded]

I have had modern material applied to my clutch plates and chain wheel. they are now thicker than they were and i need to turn them down to thickness.
As I have to fit 3 friction plates and 3 plain plates even with the originals it was a little crowded and the top plain plate was just about engaging with the centre.
The parts book says 2 friction plates 7/32" thick and 1 friction plate 23/64" thick, which i assume will be the outer plate.
Has anyone got measurements as to what thickness the chainwheel linings should be, I know that I cannot make the rear lining too thin as the chain will start to rub on the kickstart quadrant or shaft..john