AJS Model 18CS - unusual parts identification

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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dave16mct
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Re: AJS Model 18CS - unusual parts identification

Post by dave16mct »

The brackets on the l/h side on yours have been cut down for some reason. Should be easy enough to restore to the original shape. Yes the rearset rests were ordinary pillion rests used up till 1954. I don't think I took any pics of the one I saw at the Mersea Island Jampot Rally. I wonder if anyone else remembers it? Yes it will make a great project. Funny, I know someone who has returned one to standard trim!
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Re: AJS Model 18CS - unusual parts identification

Post by G15 Roy »

I have a 1949 Junior TT Clubmans 350 with the same folding foot rests.
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dave16mct
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Re: AJS Model 18CS - unusual parts identification

Post by dave16mct »

Any pics Roy?
Feral
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Re: AJS Model 18CS - unusual parts identification

Post by Feral »

Thanks again fellas for the information.

Now that the frame question is answered and I can now see what needs to be done to repair the cut bracket.

I also now have some leads on the forks to investigate and thank you all for your comments.

There is still the nagging question about the engine. It is stamped as 51, but to be fair, from the standard of the stamping, this is likely to be unreliable.

Are there any tell tale signs from the outside of the engine that will confidently identify it with or am I going to need to delve into it and measure the bore size and check the crank number?

The barrel states WELLWORTHY.AL-FIN.AFD155
PAT.NOS C.1 599684
599725 606330

All letters and numbers are raised in the cast apart from the C.1 which is stamped.

There are 21 fins.

I apologise for all the questions, but as I said earlier, I am a novice to the marque and despite hours of trawling manuals and the internet, I am getting no where with the engine. The expertise of the forum has got me along way already. :D

This bike needs work just get it road worthy and I need your help, so that I can buy the correct parts in the coming months.

All knowledge and pictures (Roy and Dave) gratefully received.
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Cjay59_LAPSED
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Re: AJS Model 18CS - unusual parts identification

Post by Cjay59_LAPSED »

Wellworthy is an alloy barrel upgrade, mine is a 500cc (18s) as stamped on the bottom end, could you post a photo of the numbers on your engine,
AJS AL FIN 500cc 1952 001.jpg
AJS AL FIN 500cc 002.jpg
AJS AL FIN 500cc 1952 003.jpg
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Re: AJS Model 18CS - unusual parts identification

Post by Cjay59_LAPSED »

Spriddler shared this when I asked the question, my machine is in the barn at the moment, if you need better photo's let me know, Cliff
Wellworthy Cylinders.jpg
AJS 18s 1956.jpg
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Re: AJS Model 18CS - unusual parts identification

Post by Cjay59_LAPSED »

Also take a look at forum thread, G80/Model 18, 'Ebay Motor'.
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Re: AJS Model 18CS - unusual parts identification

Post by Dixter »

Hi Clifford, would kindly tell me what brand and size tires are on your lovely 56 Ajay? Thank you.

Ciao, DC
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Re: AJS Model 18CS - unusual parts identification

Post by Feral »

Thanks Cjay59,

great looking bike. The engine looks like mine.

Below is a picture of the numbers. I think that it is fair to say that the crank case numbers are not legitimate, judging by the poor quality of the stamping and being in the wrong font. I am pretty sure that I have seen this number in one of the service books, but not sure which one. A ringer, I think.

The C.1 however on the barrel looks original, but what does it mean?

Am I write in thinking that this is a competition engine as the dodgy crank case numbers state?

Now I am piecing the puzzle together and thinking that the frame is a TT clubman's from between 1951 and 1953, the forks are from possibly a 1947/48 bike, the gear box is a Burman B52 C type from 1948 and engine is 500 C with an after market barrel from between 1951 and 1955.

If you know otherwise, please let me know and thanks for all your contributions.
AJS Model 18 Barrel resized.jpg
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Cjay59_LAPSED
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Re: AJS Model 18CS - unusual parts identification

Post by Cjay59_LAPSED »

Hi John,

I wouldn't trust your engine stamps, they don't look right I'm sorry to say, but others here will have more experience and I would hope others will comment. But mine is also not a competition engine, and I don't mind. The alloy Wellworthy barrel reduces weight and centre of gravity. I want mine as a road bike, an Enduro basically so having a lighter road geared bike, styled the way I like is better than a true Trials or Competition machine, so I think it all depends on what ultimately you want to do with your machine. As a true CS holds a premium value, there will always be people who will try and forge them.

I agree the C.1 does look original, but sorry, I don't know what it means.

If the engine was a true competition engine I would be surprised if someone re-stamped it, others may know of differences that could tell you if it was a comp engine.

I don't know where you found the date for the gearbox, as I understand it the 52 stands for it's introduction year, 1952, they came in road ratio, close ratio and trials ratio, and they were used by AMC from 1952 to 1956, the trials until 1955. Post a photo of the stamp and should be able to tell your more.

Can't help with the forks at the moment, trying to identify my own, and I think your frame has been already been sorted. Hope this all helps, try and have a look at Roy Bacons, AJS & MATCHLESS - Post War Models.
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