- NEWCLUTCH S.jpg (179.94 KiB) Viewed 2184 times
I put this little mod together after seeing something similar posted by Rob Frankham on the BM Bikes forum. It halves the effort required from my poor old left hand and
should make clutch operation significantly smoother. It is particularly suited for the pre '81 bikes, which have a notoriously heavy clutch with a quite abrupt engagement.
Apparently the idea has been around for a long time. There's a kit available from Craig Vechorik at Bench Mark Works that uses a chain and pulley:
http://www.benchmarkworks.com/articles/ ... lutch.html
- Vech.jpg (21.59 KiB) Viewed 2184 times
I gather these work very well but fitment involves cutting the clutch cable. The arrangement I'm using can be fitted in a few minutes with no modification to OE parts.
- NC BITS.jpg (362.03 KiB) Viewed 2184 times
There are a lot of different ways to skin this cat. Mine uses a genuine crusty old rear wheel spoke as the connecting rod, shortened by 70mm and threaded M4. The sheave is printed ABS, 32mm OD with a pressed in aluminium bush. The frame and fixing bracket are fabricated from 1.2mm stainless sheet. The extra nipple was saved from a dead clutch cable, or can be easily cut from 8mm aluminium rod as shown in the above pic. Incidentally, in use the pulley sheave rotates back and forth through ~30 degrees.
The end result is that I can squeeze the clutch lever to the bar between thumb and forefinger. I had already fitted the lighter clutch diaphragm spring as sold by Motobins about 10 years ago. I haven't had the opportunity to use the mod in anger, since the old dear is having some shed time at the moment. Static testing with the bike in gear confirms that the clutch engages and disengages as it should.
