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Rob's WD16H and Big4 Forum

Dutch army, Johan Herman Fuhler, somewhere between 1945 and 1950

Rob's WD16H and Big4 Forum
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16H Clutch drag

My 16H is a 1947 model with Roadholder forks, so yes it just missed the war.
It has been fully restored and is now on the road but the clutch drags badly. I have replaced the g'box thrust washer, so any end float is now minimal, perhaps 0.020"at most.The springs supplied were very strong and I couldn't get the adjusting nuts to clear the chaincase without making the springs 'coil-bound' ie closed up fully. Does anyone know the correct dimensions of the springs - length, dia and wire thickness.
The clutch plain and friction plates (surflex) are all new but fit well in the basket and allow the circlip to fit, ie they are not too thick it would appear.
I tried some Triumph springs I had around but they allow the clutch to slip as well as drag.
Anyone any ideas?

Re: 16H Clutch drag

John, the clutches can be a bit problematical to set up, especially if you have the original basket with corks pressed in.

My clutch is a 'bitsa' using a later AMC plain drum with a bonded friction back plate which solves that aspect and I have fitted matched springs with shouldered screws from Ken McIntosh. The clutch is light and consistent.

I should say that in my particular WD16H chaincase, the thicker back plate and alternative screws did give clearance problems (but my case had been bashed to b*ggery). In the end, I had to get a nice man with a lathe to make some slightly lower screws (this is not a problem on the Manx racers that Ken usually supplies and I'm not sure if it is in all chaincases).

It's certainly worth having a word with Ken as he also converts existing drums.

Re: 16H Clutch drag

Thanks Rik, I inherited the new clutch bits with the bike and following your comments I think the basket must be an AMC replacement, it has friction material on the outside and inside faces.
I also find that it takes 4 not 5 friction plates and 5 not 6 plain plates. I tried to fit the additional plates this morning but the basket is not deep enough. I can't get the circplip on with a stack so high. For reference the friction plates are 5.0mm thick and the plain plates are 1.4mm thick (these look original).

I will email Ken McIntosh as you suggest. However I am going to Netley Marsh next week and thought I might be able to get some help there and maybe buy the correct springs, do you happen to have a spring that you could measure?

Or can anyone else out there measure one for me. The same springs were fitted to ES2 and Model 18 models as well-Part No A2/399.
The springs I was supplied with are 44.4mm long, 17mm dia, wire dia 3mm, which are either too long or the wire is too heavy a gauge.