rear frame loop 1954 G80CS

charlski · Post by **charlski** » Mon Sep 24, 2012 12:38 am

Hi there can anyone tell me the difference between the rear frame loop on a 1954 G80CS and a 1954 G80S, they both have different part numbers, whereas the front frame has the same part number. How do i visually distinguish between the two. thanks. KC

Marty · Post by **Marty** » Mon Sep 24, 2012 11:36 am

The most noticeable difference is the comp frame has lugs where it mounts to the top of the front loop. The road frame has the frame tube squashed and drilled. Not sure on '54, but I think the comp loop has no left toolbox mounts.
Marty

charlski · Post by **charlski** » Mon Sep 24, 2012 12:14 pm

hi marty thanks for the answer, so the rear frame loop on the comp model is lugged where it joins the front frame at the top. the rear loop im looking at has 2 small brackets either side of the tube that is running down from the shock mount to bottom of front frame about 2 inches after the bend in the tube ... does this sound right for this model ?? many thanks KC

Marty · Post by **Marty** » Mon Sep 24, 2012 10:57 pm

Those are the toolbox mounts. Only on the right side ? They should both be facing inwards towards the wheel brazed to the 'inside' of the loop- not either side
MartyEdited by - Marty on 24 Sep 2012 10:01:13 PM

Rob Harknett · Post by **Rob Harknett** » Tue Sep 25, 2012 1:00 am

One sure way to tell a comp frame if complete and original is by the frame number.

Marty · Post by **Marty** » Tue Sep 25, 2012 5:57 am

The question was about the rear loop Rob, hence my answer. The road and comp front frame is identical apart from the little c after the number.
Also, after all this time(60 years), someone may have fitted a road rear loop to the front and this would not be a comp frame. Or would it, as the number would be correct ? ?
MartyEdited by - Marty on 25 Sep 2012 04:59:15 AM

charlski · Post by **charlski** » Tue Sep 25, 2012 10:43 am

Hi Marty thanks ... yes that was what i was looking for, its a correct cs front frame, but looks like a road rear loop has been fitted, it has no lugging at the top as you suggest, and the brackets are where you say, but one on either side not just on one side ... many thanks for making this clear KC

Rob Harknett · Post by **Rob Harknett** » Tue Sep 25, 2012 12:11 pm

Yes I understood the question about the rear frame loop only, which is why I said if the frame was complete and original, the frame number will tell what the bike year and model is. It is not just the little c on the number, comp models do not use the same seris of numbers as road models. so the complete number tells year and model,
Unlike road models, which will only tell the year. You would need the dating officer to confirm the model and the marque, you would probably know if its single or twin, but still need factory records to confirm actual model and if its AJS or MatchlessEdited by - Rob Harknett on 25 Sep 2012 11:13:09 AM

Marty · Post by **Marty** » Tue Sep 25, 2012 10:48 pm

True Rob, but my point is that after all this time if you don't know the physical differences, how can you tell if the frame is original if only going by the number ? Interchangeability is one of the good things about AMC machinery, as well as one of the pitfalls for someone who has limited knowledge of the marque. As in this case, a road rear loop has been fitted to a (possible)comp front loop. Only the number can determine that as they are otherwise identical
Cheers
Marty

Rob Harknett · Post by **Rob Harknett** » Wed Sep 26, 2012 1:00 am

True over the years many changes get made to bikes, clues can be found in parts lists, but much easier if someone can point out something very easy to spot, that will ID a part.