While the primary was open on my 67 Victor for rotor replacement, I decided to replace my worn clutch with parts I've bought over the last year: a B50 hub and copper thrust washer, new chainwheel and last week a B50 inner (without the lip). With my original clutch I had to add an extra 5th driven plate at the end. It all worked well but was tired: the teeth on the chainwheel were very worn, and the back of the spider needed to be machined, the slots were hammered, etc..
I assembled everything today with 5 plates each but even with the screws heads threaded way past the top of the lift plate it was totally slipping when kicking. So I added a 6th driven plate on the outer end and that cured the problem and the bike started, and at least no slipping there.
The problem is the stack is now so tall the clutch adj. nut on the lift plate rubs on the back of the inspection cover and I can't tighten it up My spring cups are 7/8", the springs have 8 coils and the old driven plates are .064 thick (the 4 new ones I bought turned about to be about .052) Any ideas? Remove the extra plate and use heavier springs? Something else?
TheB50 cover, if it's deeper, might cause problems with the '67 foot rest arms. My clutch arm is at ~1:30, and only about 1/16" of the rod extends beyond the clutch nut. I'm using an alloy lifter plate but it is exactly the same depth as stock. I'll try a set of EdV heavy duty springs I have next and if that doesn't work I'll mix and match my all my springs and cups (7/8 & 1") and hopefully something will work without the extra plate. Thanks Kommando
I wondered about the speculation that B50 primary' covers are deeper than earlier covers. Realize that all of the OIF singles from 71 to 73 had the 5 plate clutch with thrust washer. The B25, B50 and T25. So I got more than 10 covers from the mid 60's on, something from everything, TR25W, B25, C15, B44, B50. I could measure no discernable differences so as far as I can tell that myth is busted. Also realize that the clutch parts are identical save for a transition at some point to deeper spring cups. The chain wheel has the same dimensions on all models and the center is the same height as well as the rear retaining plate and nut stud lengths. So if none of the part are any "taller" overall why would the primary' need to be deeper?
I have had problems with alloy pressure plates and slipping clutches so I don't bother with them any more. I have had a couple slippy clutches that the only remedy was fitting Surflex plates. The super heavy duty springs suck to use and should not be necessary in a B44.
A 5 plate B50 clutch in good condition should not slip on a B44, and the 6th plate cannot usually be added without skiving off the "corks" off the back of the first plate. The 6th friction plate would add another .117"-.120" or so which probably creates the clearance issue.
How thick are your friction plates? If the hub and chainwheel are used, did you file the slots to allow the plates to slide in and out easily? Also, I'm surprised your clutch rod was long enough to lift the pressure plate at all with 6 plates. I've had to make longer clutch release rods to accommodate the 6 plate conversions.
And lastly, what kind of oil are you using in your primary? Some new oils are too slippery for the clutch, so make sure you are using oil designed for use in the primary.
I think the primary cover on my B50 race bike with the 6 plate conversion is from a B44, and no issues with clearance.
Tom, I thought the issue was my friction plates are .134 (and I thought stock thickness is 0.167?) I did try Peters suggestion to use the stock lift plate (and not my alloy one) and all seems to be working well with 5/5 plates. I'll see if that holds up. Thanks all Adam
Adam, All the friction plates I have measured have been .120" or less. So even with 5 of the .134" thick ones, you would be about .070" thicker than my clutches which could be part of the problem. I have read about the stock .167" (Rupert's?) but have never seen one that thick. I have some new Surflex ones out in the shop which I may get to measuring tomorrow to confirm. If your clutch is now working fine, then so much the better. Tom