250 cc G14 Lightweight frame

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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David Paterson
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Joined: Sat Sep 11, 2010 5:23 pm
Location: ESSEX UK

250 cc G14 Lightweight frame

Post by David Paterson »

I have two 250cc G14 CSR motorcycles which I am refurbishing. One was registered in 1962 and appears to have a slightly larger frame than the other which was registered in 1967.
On the earlier bike, there is a larger gap between the engine and the top frame tube and the carb inlet is lower than the cut-out in the batterybox cover. Also on the earlier bike one wheel sits off the ground when the bike is on the stand unlike my later bike.

Is it possible that earlier bikes were built with a larger frame or could the frame be from a 350cc Lightweight?

The frame number of the earlier bike is 12769 (although it says 2769 on the registration document.

Any suggestions/advice would be appreciated.
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ajscomboman
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Joined: Mon Jan 01, 1990 12:00 am
Location: HAMPSHIRE UK

250 cc G14 Lightweight frame

Post by ajscomboman »

The 350 has a longer front tube approx 1" and as they stopped making them in 62, my guess would be that it's a 350 frame.
David Paterson
Posts: 11
Joined: Sat Sep 11, 2010 5:23 pm
Location: ESSEX UK

250 cc G14 Lightweight frame

Post by David Paterson »

Thanks for the amazingly fast response.

The later bike measures 7 inches from the bottom bracket flange to the top flange whereas the older bike is 8 inches. 1 inch difference as you suggested.

Do you think that they originally built the bike like this using spare 350cc frames?

I have checked the frame number and it appears, to me at least, that this is a 250cc frame number.

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ajscomboman
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Posts: 3963
Joined: Mon Jan 01, 1990 12:00 am
Location: HAMPSHIRE UK

250 cc G14 Lightweight frame

Post by ajscomboman »

Impossible to tell but doubtful. A 250 in a 350 frame looks odd as there's way too much room above the rockerbox. Likewise a 350 in a 250 frame will fit but it's almost impossible to remove the rockerbox with the engine in the frame.
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