Wo's running a Brit Trans?

My Triumph Pre-Unit trans arrived a few days ago and it's got me tickled pink!
I'm quite excited to have a foot shifter behind my ol' 45!

Of course I have questions for all the guys who have also have british trannies!

Such as:
-Chain or belt primary? Do belts stretch/need adjustment?
-What front pulley (size) are you using (especially if using a belt!)
-Does anyone sell a kit in the U.S....?
Or heck, even anywhere?


I'd love to run a belt-drive primary on my 45, and I know it can be done, I just need to find out who supplies what!!

Thanks!!
(and YES, I already have the "victory" printed literature!)

there are three main problems, assuming that you don't have the Victory book which covers it all in detail.

Belt drive, good question. The belts sold for conversions on 45s don't fit; you will need to fabricate a front pulley using the inner taper from a H-D unit and the outer ring from a British one. The belt will need sourcing - no British unit will be long enough - go to an industrial supplier with the original belt and total length for this question.


1) the primary chain sizes are different, as are the sprocket sizes. The 45 front sprocket is considerably larger than the British equivalent, as is the clutch. You will need to get an old sprocket, grind or mill the teeth off and fit a new tooth ring of the required size and alignment.

2) the alignment of the chain will need attention, assuming that you have the engine and rear wheel in the original offsets then this will be evident. This is done by offsetting the gearbox

3) the back wheel will need reversing as the rear drive chain will now be on the other side. There are various ways of doing this, all require some sort of welding to the brake anchor

reversing the wheel means that you will now need a revised rear brake linkage to suit. You also need a revised gear linkage. Opinions vary on this, but the two main alternatives are;

a) use the clutch pedal as a gear pedal. This means you need a linkage across the frame behind or under the engine. Use the original brake pedal as a brake pedal, which means you need a cross-over shaft like a panhead, or a cable linkage

b) use the original brake pedal as a gear lever. This isn't entirely satisfactory but it IS much simpler to do, it just needs a rod from the pedal and a cut-down gear pedal on the selector shaft as a crank. This means that you can fit a rod or cable to activate the ( now ) left side brake; a servicar clutch pedal is ideal for this.


you will now need a clutch lever and cable to fit your handlebars. Triumph 1" dia levers are ideal for this, H-D panhead style levers can be used but you will need to make a cable.

Is it a slickshift?

I don't know actually.
Doubtful though.

I went for a chain primary on mine.

Much easier to get an engine sprocket modified.

mine has a belt drive, but I don't think I'd go to that much trouble again. For the amount of power you will ever get out of any 45, a modern chain will handle it easily and it's a much simpler conversion

The kits are out there (British Cycle, etc.), minus the engine sprocket conversion. You are on your own for that. Mine is belt driven, which turned out nice and works great so far. I do agree with 45Brit that the engine spocket conversion to belt drive was alot of work. I would look at the chain drive option if I ever did this again. My main reason for doing this was not to worry about oiling the primary. However with a single o-ring sealed chain, it probably would'nt be a big deal. I used a BSA A10 belt conversion with a Triumph style clutch running a BSA rear wheel. Good luck!