Clutch judder issues

[Exmoor beast]

I doubt if it would work on a Lav clutch. For the bobweights to be able to bring any sort of movement into the plates, sufficient radial clearance would be required. Both the friction and plain plates of the Lav clutch are more-or-less a sliding fit on the hub and basket, with no room for any sort of radial movement.

My experiece of japanese clutches is that they generally have pretty loose-fitting plates, which may contribute to their usually smooth action.

piet

Japanese clutches also spin faster, slow clutches are always grabby. Took BMW about a hundred years to speed the clutch up!
We used to fit Barnet clutches- measure up the same but never as good as genuine Japanese. Having the steels shot penned softens the working edges , and tuning the springs might help. Probably just too big and heavy.

 

[piranha-bro2]

Woulda though Beemer clutches spin at crank speed ... Laverda clutches spin at about 1/3 crank speed (whatever the ratrio is b/w primary and clutch sprockets).

 

[sfcpiet]

Beemer clutches run at crank speed. Reckon being so grabby has something to do with their size and being dry, single plate.

Not so sure jap clutches spin faster in relation to crank rpm. Always found their primary ratios to be rather low, more like 4:1 in comparison to the 750s 2.2:1(25/55T). Triples are slightly lower, 25/60-something iIrc.

Jap clutches often use a very large gear at the clutch to bridge the gap from mainshaft to the crank, GS/GSX Suzuki and Kawasaki Z come to mind.

piet