The Suzuki clutch conversion for the BSA uses some Suzuki GS550 and some newly made parts I believe. I have a friend who has one fitted to a pre 65 scrambler and he speaks very highly of the conversion. Many Jap bikes have a gear driven primary side but obviously a chain drive is needed. I would look initially at removing the clutch basket of the Matchless clutch to leave you with just the sprocket, the center that fits to the mainshaft and bearings.
Next look for a Jap clutch that is the right depth to fit in the Matchless cases if mounted to the original sprocket and has a large enough diameter internally to clear the bearings,clutch center etc.. We're not talking massive horsepower so the clutch from a relatively small donor bike might be suitable I would have thought...perhaps a 250?
These are easily removed from the drive gear as the basket is usually rivetted to the gear...
You will have to calculate the overall depth of the clutch assembly when the two parts are matched up. Finally, you'll have to attach the Jap basket to the Matchless sprocket..I would think they could be bolted together using the original rivet holes as a guide and ensuring it is all concentric. You will also have to find a pushrod operated clutch, many are lifted from the outside and don't have a pushrod.
Other considerations are availability of the parts for the Jap clutch you choose, removal of the clutch from the bike, pushrod operation and length, amount of lift relative to space in the Jap clutch basket and pressure plate arrangements for the pushrod to operate against ,arrangements for holding the clutch to the mainshaft if not standard, whether you retain the original bearing set up etc. etc.
Without knowing exactly how the Matchless clutch is laid out or which clutch you might choose as a donor these are really just a few general thoughts on the areas to be sorted out....Ian
email (option): ian@wright52.plus.com
I used a Newby kit on my B33 for a while...It's a really well made kit with a proper solution for the clutch bearing etc. However, there is no shock absorber in the clutch and you lose the one on the crankshaft due to the pulley width. I found this made for a pretty harsh transmission for road use and I removed it in the end. With belt kits you need to consider the width vis a vis the clutch casings on earlier bikes which often have narrow cases, the difficulty of altering gear ratios (which requires a new pulley each time and also the cost. The Newby kit was over £400 quite a few years back...Ian
email (option): ian@wright52.plus.com
hi robb,an e-mail to this guy may be helpful,he does all the clutch parts for triumph bsa norton and can inter change parts to suit every taste .he may be able to offer advice etc.the ajs and matchless used a very similar box to the norton,
i think it was reffered to as the amc gearbox so spigots etc may or may not be similar
http://www.motorcyclewebsite.com/tony-hayward
cheers rick
email (option): richardholt@rocketmail.com
I can't say I'd follow Peters line of thinking which to me seems very extreme...Rather, I think I'd go with the old adage 'if it ain't broke, don't fix it'...If you can get spares and the original design is sound and suitable for the way you intend to use a bike there is little reason to modify anything. If that is not the case a well thought out modification can solve the problem and improve on the original set up. Or you may just regard the original machine as a base on which to create your own version of the type.
Some of the problems associated with these old bikes are a consequence of how long ago they were designed and built. For example, the M20 gearbox had no effective oilseal only because the materials and technology weren't available at the time. Not to fit a sealed bearing, which is readily available today and effectively cures the problem would be an odd strategy...
I confess to being a 'serial modifyer'..I am always looking to make what I feel to be improvements. Many of them have been successful, a proportion haven't been and there is no doubt that I have learnt to be very thorough in thinking through all the implications of making changes before taking action.
On 'standard' bikes where there was no intention to modify, this has always been as a result of what I considered to be a real fault or an outdated design feature which could be altered, usually to increase its longevity.
However, if the 'modification' route is followed too much there is the arguement to consider that you may alter the experience of riding your particular old bike to such a degree that you no longer have the real experience of how the machine was when it was produced....
My B33, which has an enlarged engine and numerous other modifications falls squarely into that category I would say...but then I did do 70,000 plus miles on it before I changed it very much and it was never my intention to preserve it unaltered for posterity....Ian
email (option): ian@wright52.plus.com