650SS heavy clutch

I also fitted a new clutch cable with a nylon linedouter cable. I found it evenheavier than the old, stick/slip cable it replaced, so much so I was afraid of pulling the nipple off the inner.I removed it to replace it with the old cable, but decided to try a little heavy machine oil runthrough it. When I re-installed it, it was an instant success, with asmooth and light clutch operation.

Below is an extract of a previous contribution regarding my experience with a (very) heavy 650SS clutch:

Step 1Renewed clutch plates (used Barnett plates sourced from Steadfast USA as cheaper than UK sources) - well overdue as these have been in there since I've owned the bike [30+ yrs!] and well stuck together.Result - much improved lever pull but still quite heavy - mind you anything would have been an improvement!Step 2Measured fulcrum point to find I had a 1 inch lever fitted (also been there over 30 years). Based on previous response purchased correct 7/8 inch lever from AMC Spares (part no. 022718, ordered by phone, delivered next day - excellent service). Fitted using my original perch.Result - significantly lighter pull.Note - Norton Maintenance manual states on page 34 that you should use a 7/8 inch fulcrum lever - is that authority enough - only saw this when I was using manual when replacing my clutch))

Step 3Fitted featherlight clutch cable from Venhill (again next day delivery).Result - a slight improvement but not that significant - still probably worthwhile doing.Have I a two finger pull clutch? Yes but only as a party trick!

All the above steps were done on successive days so that I could make direct comparisons.

Hope this helps.

My 99 clutch was light compared to other Nortons till I fitted some Norton straight bars, This drags the cables over the fork tops and puts the levers at an angle the my forearms and wrists. I'm looking for some bar risers about 30mm ,there are some on E-Bay ,has anyone tried this on a Norton?.There is a small mod reshaping the ramp on the arm in the box which costs nothing ,this helps as does only doing up the springs enough to stop clutch slip.

hello My Manxman 650 I fiitted a Venhill Featherlight Cable with the right lenth , and fitted new clutch plates and center rubbers and Spider has it was lose on the shaft end with the centre nut done up ! now I have a good light clutch , also I filed any small buers on the basket and center hub yours anna j

Hi David, The 7/8th center/center lever was the standard Norton clutch fitment for road twins. Interestingly they did not always use the same for the front brake .So you would find a 1 1/16 lever paired up with a 7/8th. It was probably not critical for a Manx as most riders would not be using the clutch hardly anyway!!.Only last week I was spouting off to a young Ducati racer who was having arm pump problems when he put me straight with " can't be the clutch,don't use it!".It would be more important to get the extra lift on a Manx as bump starting with a slightly dragging clutch is not fruitfull.

Hi David

After reading this thread I thought I would see if I could get my 650SS clutch any lighter. The biggest improvements have been a new clutch lever without an adjuster (7/8" throw), a Venhill nylon lined cable, and 3 1/2" rise bars from Les at Norvil. The bars let the cable go in the correct direction as it leaves the lever bracket, also it allows me to point the whole clutch lever assembly down at 30 degrees which has eased my hand pain immeasurably and seems to have done the trick without having to take the chain case off to adjust anything in there. The flat bars whilst looking the part are I believe at least 50% of the problem. Les has a smaller rise bar which would look a bit better but sizing it up with my Sunbeam they are almost the same ground to bar height now and the bike is a lot nicer to ride now. RegardsGromit

You may have some deformation of the cam lever where it contacts the roller in the release mechanism. This causes the cam to bind in the fork. Also a later cam should have a hardened surface and a different (better) cam profile. (the part the cable fits into) you can remove the cam with the outer cover off (not the inspection plate) and dress the cam where it contacts the roller. If it's not hardened, it will gradually deteriorate again. You could case harden the surface once you are happy with the profile.

Have you checked the clutch springs themselves?

Perhaps a previous owner used some aftermarket units. Or maybe springs from a Commando?

Mike

Doesn't a commando have a diaphragm spring? I found that springs from certain suppliers were variable in tension and very different from some genuine ones that I inherited. To check spring are equal, take a length of studding put two springs head to head separated by a suitable washer, then assemble with a washer at the outer ends and a nut at each end. tighten the nuts until one spring is reasonable compressed, measure length of each compressed spring these should be equal. dismantle and substitute springs until you have a set of equal tension.

Helps if you have at least one genuine spring for comparison

Drillpress (orsimilar) and a spring balance dofor me.... compess the spring on thedrill presstill onethird compressed(or arepeatable distance)by pulling on the spring balance. Takethereading off the spring balance...compare all andthree orsix match accordingly.Anyimbalance will giveyourbasketdrag issues eventually....