Off Post, but interesting application I thought.

http://victorylibrary.com/tech/enigmas.htm

email (option): unpob@yahoo.com

It's quite a normal conversion on this side of the water, most of the 45 gearboxes are clapped out and need a fortune spending on them, so I guess it was a natural thing to do, to fit a readily available box that most custom bike builders were familiar with as the workings of a 45 box are alien to most British mechanics

email (option): davmax@ntlworld.com

By coincidence, today I've just fitted an identical belt drive to one of my T140s - except that I've got a three spring clutch. That's a Tony Hayward aluminium alloy clutch pulley that's no longer in production. It uses replaceable pins around the inside of the drum that engage with notches in the steel plates. The friction plates engage with the hub (a reversal of the standard Triumph set-up). Easy kit to fit (had it lying around for maybe 20 years).

Unfortunately, I've now got to strip the clutch hub again to grind off some material from the gearbox crossover shaft that's rubbing on the pulley. Pain. I was wondering (earlier) if anyone has ever fitted a toothed belt to a WM20 and was trying to find a reason for why you'd want to. Makes sense on a triplex chain T140, but I couldn't think of why you'd want to muck about with the standard M20 set up - especially as you'd lose the crank shock absorber (which works fine for me) and would have to run a clutch shock absorber (with, apparently, a smaller arc of movement). Of course, fitting a belt to a Harley is practically de rigeur. But that M21 gearbox adds a new-ish take on it.

email (option): dannydefazio@sumpmagazine.com

I ran a Bob Newby belt kit on my B33 for a couple of years. Mainly to do away with oil, gaskets and leaks. I selected the Newby kit as it has a sealed radial bearing in the back of the clutch so there were no issues with the (non) lubrication of loose clutch rollers. The clutch is ,I believe, Jawa speedway based.
Unfortunately that meant I had no shock absorber at all and despite a small degree of 'give' in the belt I always thought the power take up was a little harsh. For this reason I eventually removed it and now run a Triumph clutch and chain (with oil).
The Newby kit is good quality and for racing applications, for which it was designed, it is very good. They don't worry overmuch about smooth power take up!
I think on balance, even if you have a kit with a shock absorber they are probably not really worth the substantial cost. I suspect with a few modifications I could cure any oil leaks for a lot less money and that is really the only problem with most chain drives on older bikes.They don't require a lot of adjustment and the chains last pretty well as long as they are lubricated sufficiently...Ian