Petrol tank rear mounting

Information relating to the Matchless G12 or AJS Model 31 650cc twin
Locked
rasp19
Member
Posts: 2
Joined: Mon Jan 01, 1990 12:00 am
Location: TONBRIDGE, KENT UK

Petrol tank rear mounting

Post by rasp19 »

I have bought a partially restored G12 and am in the throes of finishing the job.

My problem, as with many dismantled bikes, is the missing bits! I don't have the rear petrol tank mounting clip part no. 026626 and no one seems to stock one. Furthermore, the AMC parts list does not give an image, so I don't have a guide for fabricating one.

I'm also not clear as to how the assembly would go together, but that might be helped if I could see the part.
Can anyone provide an image of the clip and indication on how the rear rubber and clip go together, please?
User avatar
dave16mct
Member
Posts: 3234
Joined: Mon Jan 01, 1990 12:00 am
Location: LANCASHIRE UK

Re: Petrol tank rear mounting

Post by dave16mct »

It's a semi-circular clip with 2 short tubes welded on to match the other half welded into the tank tunnel. The tubes line up with the 2 studs which reach down from the tank tunnel. I haven't fitted mine for around 10 years, can't be bothered with it. The weight of the fuel and the seat holds it down. Just put plenty of rubber under the tank rear.
Dave.
rasp19
Member
Posts: 2
Joined: Mon Jan 01, 1990 12:00 am
Location: TONBRIDGE, KENT UK

Re: Petrol tank rear mounting

Post by rasp19 »

Thanks for prompt response, which fits with what I expected. I may have a go at fabricating a functional substitute, but the gravity alternative is likely to win. (Something that I practised all too often in my distant misspent youth on my 1953 G3LS, with the tank retaining bolts disappearing too often, sometimes through lack of wiring. Happy days!)
LynP
Member
Posts: 335
Joined: Mon Jan 01, 1990 12:00 am
Location: GWENT UK

Re: Petrol tank rear mounting

Post by LynP »

Hi rasp19, I needed the same clamp a few years ago and I have attached a photo of the one I bought from the club spares when they had some made. I have also attached a picture with measurements, I don't remember this information came from, it may even be in the club archive, because I bought the one from the club I did not make one, but hopefully the pictures will be useful. Sorry I have been so long posting this but I am having trouble loading the photos, so I hope they load OK now. Best regards, Lyn
1961 Twin Petrol clamp Dimensions(2).JPG
1961 Twin Petrol Clamp underside2.jpg
1961 Twin Petrol clampTop2 (1).jpg
You do not have the required permissions to view the files attached to this post.
User avatar
dave16mct
Member
Posts: 3234
Joined: Mon Jan 01, 1990 12:00 am
Location: LANCASHIRE UK

Re: Petrol tank rear mounting

Post by dave16mct »

Yes I knew I'd seen it somewhere, it's in Photos, Post war twins parts.
Dave.
John Jarrett
Member
Posts: 438
Joined: Wed Oct 12, 2005 10:45 pm
Location: MIDDLESEX UK

Re: Petrol tank rear mounting

Post by John Jarrett »

A twin conrod cap will fit if you have one spare.
Steven S
Member
Posts: 52
Joined: Mon Jan 01, 1990 12:00 am
Location: BEDFORDSHIRE UK

Re: Petrol tank rear mounting

Post by Steven S »

If you ever wonder why the 1960-61 tanks are hard to come by, that clamp is part of the reason. Even with the correct rubbers fitted to the clamp and the corresponding bracket on the tank, it's too rigid and the vibration causes the tank to split up the centre seam. I have seen several early 60s tanks cracked in this way. I always left my CSR tank unsecured at the rear and sitting on a piece of foam rubber because the weight of the fuel in the tank and my weight on the seat were enough to keep it secure. I am sure AMC quickly realised this, hence the switch to the rubber band and hook arrangement in 1961.
Locked