1951 Competition?

[richson]

I recently bought what appears to be a competition model. There are a few bits missing and the tank is from a Mk 4/5 I think. After reading some of the identification help on this site, I am not sure at all what it actually is.
The engine is 11126/5 - a Mk 5 unit.
Gearbox is 1105 marked "comp".

The frame no 7566/4 has me stumped. It has a rigid rear end, but it is fitted with pillion footrest lugs. The forward engine mounts point upwards. It certainly looks like a competition frame, but the no and those footrest lugs don't add up.
Any help?

Neil



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[Chris]

Hi Neil
It sound like you have a genuine "Comp" frame. The footrest lugs were standard on the rigid frame and the frame numbering followed the Mk. 4 numbering with a stroke 4 on the earlier models then stroke C later. Your number seems to fit well with the early 1950 year of manufacture. You clearly have a Mk. 5 engine and a Mk. petrol tank. The Comp tank is similar but with flat sides.

It is very easy to stamp "Comp" on the gearbox and the only way to tell reliably whether it is a genuine Comp box is to take off the gear selector cover when, with a torch, a stick of chalk and some patience you can count the teeth on the gears. On the Comp box the first and second gears are lower and the pinions on the mainshaft have, from memory, 36 and 31 teeth compared with 34 and 28 for the standard Mk gearbox. There were a few special Comp gearboxes made which also had a lower third gear.

You should have a 19" WM3 rear wheel and WM2 21" front. Many Comps have had 18" rims fitted at the rear since 19" x 4" trials tyres are virtually unobtainable.

The original fitment was a rubber saddle. These are available in limited numbers from some sources.
Also the original fitment was a siamesed exhaust with only one silencer on the right hand side.

You should have some fun with it. I spoke to Sammy Miller a few weeks ago when he told me it was the worst trials bike in the world. However I have seen these bikes used in trials and on one where I was observer of a section, a rider won on a Douglas with an amazing score of something like one dab in five circuits of about a dozen sections.   Chris.     

[richson]

Hi Chris, thanks for that.

The rear wheel is a 19". Although the front wheel looks big in the photos it is actually 19" also. The rubber saddle is long gone, and the leather on the one I have is split all over. A new cover is definitely needed.

I've been dismantling the bike today, and there will be quite a few parts that I will have to replace. All of the common wear items are in pretty bad shape (apart from the tyres which are brand new). Both exhaust pipes are cracked, and the silencers are 30% filler (these are marked "unity spares"). Some of the cables are frayed etc, and most of the rubber badly cracked.
I think there should be an air filter box underneath the saddle but it's gone.
There is what appears to be a circular boss with four tapped holes in it on the gearbox immediately above the kickstart shaft - do you know what it is for?
This is going to be a fairly long term project. I know the bike is not  "original" but I am going to completely restore it in any case.

Regards,

Neil

[Daren W Australia]

Hi what a great looking bike I want one Regards Daren