G12 Fuel tanks

[rolana]

I have seen mention of different sized fuel tanks for G12 models (and AJS I assume). Any comments or information?
rolana

[ajscomboman]

Bit of a minefield Rob. For 1959 a new 4.5 gallon tank was introduced with a centre seam and narrow tunnel as it only had the single front down tube to clear. It also had 4 mounting bolt holes . For 1960 the tank had a wider front clearance to accommodate the new duplex frame the rear mount also changed to a split clamp. The front mount changed again to sockets to accommodate an expanding rubber fixing. The rears changed for 62 to 2 welded spigots to which a rubber band attached and ran under the frame top tube, also to stop the tank touching at the rear there was a rubber and foam packing piece. 59-61 had bolted on knee grips and chrome panels depending on model designation. 62 only had tangs for knee grip attachments that were also the same as L/Weight models and the badge fixing centres were widened to accommodate the large Knee Knocker type. 63 saw knee scallops and stick on knee grips along with the Knee knockers and NO welded centre seam. The final change was to revert back to the narrower badge fixings and plastic.

Then there is the alloy comp tank which was 2.75 gallon ish, rear fixing spigots and hollow tube front fixings.

Bet you wished you hadn't asked!

At least my centre stand is more straightforward!

[rolana]

Much appreciated! I was intrigued at the mention of a smaller tank in other items I have read.
Thanks for your input!