Vintage Workshop
Services for Brough Superior motorcycles and their contemporaries

A gear lever and gate for the Montgomery (4-speed Albion gearbox)

For a long time, all I had was a catalogue picture. Fortunately, most catalogue pictures show the right hand side of a bike!
Then, my friend Christian lent me the gear lever off his 750 Montgomery. This looks a bit different as it is straight, but apart from that I think it is rather the same. Here you see it fitted to my bike.

The bit that bolts to the rear tank mount is a casting. If you take a close look, you can see  there is a lug for a third mounting bolt on it, right in front of the r.h.s. tank bolt. This bolts to an additional thread in the tank, presumably to give the whole thing a bit more stability, as the two tank bolts are supposed to be mounted with thick rubber washers.

I can't help thinking this is a very, very poor design. You want to isolate the tank from the engine vibrations, and then you bolt it rigidly to the gear lever bracket, which again is bolted to the frame - oh my dear!  

2/2008: I had this extra thread replicated on my petrol tank, but when making the gearchange lever and bracket, I decided to ignore originality and make a small design change.

I welded an extension to the tank mounting bracket, to which the extra bolt will attach. And I made another thread on the left hand side where the gearchange bracket bolts to the tank mount. This way I can put the tank on nice soft rubbers without the gear lever being wobbly. And the gear change gate won't fall to the floor when you take the tank off!

I agree this part is historically wrong, but it will certainly improve the roadworthiness of the bike. The historic side is interesting, however. It shows a very typical thing happening in (dare I say, specifically English?) motorcycle evolution: Many new features were just added on with a minimum of change to the existing design. I suppose when the market demanded that the gear lever moved from its old place on the gearbox to the more convenient position at the tank, the tank mounts were just the next best existing attachment points. A suitable bracket was made up and added to the old frame and that was that. Only very few bikes afforded a specific frame lug to carry the gear lever and gate (I think the 1927-ish V-twin AJS's and Enfields did, not sure about Ariels)

George Brough did not do much better, but at least he attached his gearchange gates with extra bolts from the start, instead of having the tank bolts doubling up as gearchange mounting bolts. In this respect the 4-speed handchange on the mid 30's 680 Black Alpine models was a sorry mistake, with the gate fitted to the tank...

The lever itself is originally also a casting, of course.

Cutting the two parts from a strip of 6mm steel was a bit tedious...

... but with a bit of filing and grinding both parts of they came out quite well.

Here I am just rigging them up for brazing them together. Yes, I almost forgot to arrange them at the 165 angle...

Here I am milling the recess for the spring at the pivot point.

This is how the thing looks on the bike.

It still wants making a gate, and maybe it would look nicer if the whole setup sat half an inch higher...

The base bit is just tacked together. I will decide this when I have made the gate and when the tank sits on its proper rubbers.

to be continued...

 

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