Author Topic: EW Clutch Mod.  (Read 3343 times)

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Offline Clive

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  • Location: Waihi ,New Zealand
EW Clutch Mod.
« on: 17 Feb 2010 at 02:44 »
Hi All,
Have been living with a slipping clutch for some time grease and ferodo just dint mix.
No matter how sparing with the grease gun it still ends up on the friction Plate.
I remembered reading in the New Conrod back in Jan 2000, Pat Gormley writing an article on MK Series clutches, removing the ferodo linings and fitting Cork as a replacement friction medium.
On the shelf left over from a kitchen upgrade some years ago was a Cork tile just big enough to allow two rings to be cut out as Pat describes the use of a Stanley knife and a bit of patience .
The cork rings are bonded on with as high a temperature Araldite  as the local hard ware store could supply. When the assembly has cured a clean up of any surplus adhesive and a little sanding to achieve the required thickness of the stack a thickness of 8.5 mm approx .
The cork surfaces where oiled lightly and the clutch re assembled using only 4 light springs much lighter than the club supply and fitted to the bike .
After a little bedding in slipping the clutch with the bike on the stand and using the back brake , the clutch action is light and sweet and so far i am very pleased with the transformation .
If there are any mayor probs will let you all know
My thanks to Pat Gormley for the idea


Offline Wilfr

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Re: EW Clutch Mod.
« Reply #1 on: 17 Feb 2010 at 11:51 »
Hi Clive,

thank you for posting this - very interesting indeed! 
On my 1938 MX80 Brough I am also using cork inserts in the clutch plates instead of the original woven asbestos ones. I have the same  experience - the spring pressure required to keep the clutch from slipping is strongly reduced, which is a real bonus for the left hand!

I think the only drawback is that the cork inserts are growing when they get hot:
I once lent the bike to a guy who had no experience of cork clutches. He left the bike in gear while held up in a traffic jam, and when the warming up clutch started dragging, he used the rear brake to keep the bike ad standstill and more throttle to keep the motor spinning! By the time I caught up with him, heavy smoke was coming out of the primary chaincase!!
Which meant I had to cut and fit another 84 (?) piece set of these little wedge-shaped inserts :frown:, but the clutch has been fine ever since.

So please keep us posted with your longtime experience - I feel a cork clutch which is not abused is a wonderful thing!