Matchless Rigid Trials gearing

[Matchymarty]

Hi all,
Some time ago I posted about the possibility of starting a Pre-65 Trials build. Life and Covid got in the way of that.

I have recently decided to go with a a rigid rear bike to start me off.
I see there are many AJS and Matchless rigid and sprung trials bikes out there , and wonder if anyone can advise me on gearing?
I'm likely to use a standard B52 gearbox, and clutch. I'm guessing I should just go for the smallest engine sprocket I can find. (15t ?)

But what are people using for final drive ratio's ? I'd like to be able to lug the bike really slow. Guessing 16t is standard and the only gearbox sprocket available?

I see in youtube videos of TALMAG classic trials, that some people run seemingly standard rear wheel sprockets, and some run modified larger ones. I'd like to know what sort of ratio's people are using...

Cheers for any help.

[SPRIDDLER]

I last rode in trials on a 197cc Villiers engined DOT back in the 60's so I've no experience of bigger 4-stokes but if you haven't found them and no-one else can help with info the Touring and Competition gearing ratios for rigid and sprung are given on page 5 in the Owners Manual.......

http://archives.jampot.dk/book/Owners_m ... ingles.pdf

and Touring and competition sprocket sizes on page 17 in the various Spares Lists...........

http://archives.jampot.dk/book/Spares_l ... ingles.pdf


I've referred to 1954 models as they use the B52 'box.

You may find the various editorial reports/reviews in the Archives of AMC trials bikes interesting, although from a very quick dip into them I didn't see any mention of gearing.

http://archives.jampot.dk/editorial/Trials/

[clive]

I ran a home made trials bike, by which I mean stripped back road bike. It was a 350 with a 15 tooth front sprocket, trials ratio Burman CP box with standard gearbox sprocket and rear sprocket. Certainly went slowly enough. The trials gearbox had a lower first gear but not massively so. Your problem i suspect will be finding the 15 tooth front sprocket. When i reassembled the bike as a road bike the sprocket and gearbox sold very well on ebay.

[Matchymarty]

Thank you Spriddler and Clive.

Spriddler : Yes thank you for the links. Lots of reading there !

Clive: Similar to you, I"m starting with a road rigid frame. I have an decided to use the ALL IRON 350cc and CP gearbox (with rusty looking clutch) that came with the bike If I can make it serviceable. Although, I do have a B52 gearbox I could use if the CP is too far gone (without a clutch).

Only thing I'm worried about with the CP is the clutch. I prefer that of the B52's. - alas that is an asside.

You are correct - IT is proving to be difficult to find a 15T engine sprocket. That said, the bike has an 19T on it now, so I'll see if I can find a 16T to start with, as I've managed to find a 16T Gearbox sprocket (from India) . So that's a start. Once I pull the CP apart, I'll see what's what, and MAYBE there might be some scope to gear down 1st gear at least if I can find any parts. (good luck)

I'll also need a new rear wheel hub - struggling to find one of those too. If i get really desparate, I could try and find someone in Australia who can make a new sprocket and weld it to my hub - and go with another 5-10 teet on it. Unfortunately in Australia, there's just not a lot of people that are willing to do things like that....