model 22 just pre war,- shock absorber primary sprocket

Information relating to Matchless and AJS Models built prior to 1939
Mikedearing
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model 22 just pre war,- shock absorber primary sprocket

Post by Mikedearing »

time to get this bike up and running again - what does the primary drive cog look like? will a 3gl fit?- I guess it has 2 ramps on it? and a spring what is the optimum amount of teeth?

especially as Im going to Banbury so it will be the usual indecision as to is it quite the right component? if I can find one...


cheers Mike
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Rob Harknett
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Rob Harknett »

What year.
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Rob Harknett »

Ashampoo_Snap_2018.06.12_09h49m09s_001_.png
These are what parts on the drive shaft look like. Ignore the part numbers as they will depend on year and model, note the first part spacer, this must be of correct dimensions, the 250 sprocket will have 17 teeth for both dynamo and drive. All will have 17T for dynamo. Only the 250's will have 17 for drive. Those 2 bits will be like looking for a needle in 3 haystacks at least. Some other parts were continued into the post war period BUT with a new part number. Which I cannot go into as you do not give year of bike. You will need to be 100% sure of what you have got. Many people are miss informed. So if they get what they think is correct, for what they think they have, find it does not fit.
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Mikedearing »

ah cheers... 17 teeth useful to know.. Ill look out - think its a 38 with the covered rockers and the large Cam plate with the logo on it bit its the magneto model with the dual sprocket... would a 3ls fit on the splines?
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Rob Harknett
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Rob Harknett »

G3L is 350 as you know. Far as I know, the G3L will have a different number of teeth. So wrong even if it will fit. Year should be on the engine. AJS valve springs were exposed up to 1936, covered 1937 & 1938, covered via valve springs fitting in a steel cup top and rockers alloy with removable half egg shell type cap, held by 2 Cheese head screws. Fully enclosed valve springs 1939 onwards. If a 37 or 38 engine is totally original. Only easy to spot difference is, 37 will have square'ish edged profile outer timing cover. 38 more rounded profile, ( part no cast inside will start 38 -22 E?? ) This cover was used up until 1953 on 500's, 1954 under 500's. It did evolve, 38 cover had grease nipple a little later this was blanked off, later still the blanking was smoothed over to match profile all round.
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Mikedearing »

its a 38 engine
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by SPRIDDLER »

I know absolutely now't about pre-war bikes, however.......
Perhaps you can beg, borrow or steal a G3 sprocket assembly to examine / try for fit etc. It would be the most conclusive way to go.
I see you are in 'London' which I understand is quite a big place, but although it's a long shot and might be a wild goose chase maybe a visit to Russells Motors at Clapham would produce something although I don't think they have much/any pre-war stuff. Give Les Myers a call first so that he's expecting you. If he's having a good day there's an outside chance he might let you take one on sale or return. Better still if you could take the bike there........
Alternatively, Steven at AMC Classic Spares has a good range of s/h parts.
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Rob Harknett
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Rob Harknett »

Mikedearing wrote:its a 38 engine
Neville the bike is a 250, 350 sprocket not suitable.
Parts for 1938 250 are.
Sprocket distance collar old pt.no. STD 630 not continued into post war years.
Sprocket pt. no. old 20815- 16 ( note 16 teeth for 1938 ) new pt. no. 017079 use 014016 ( 3 numbers to look for on NOS )
Shock absorber cam. old pt. no. STD 830 new 000830 see Club Spares.
Spring. old pt. no. STD 702 new 000702 see club spares
Cup washer. old pt. no. STD 831 new 000831 see club spares
Nut. old pt.no. STD 610 new pt. no. 000610 see club spares
So if you hurry you may get 4 out of 6 bits from club spares. It is surprizing how many pre war parts were continued in use post war. As I have said so many times, if you have a circa post 1951 bike, always convert the old part numbers to new, then check club spares. Always search for, ask and order via the new part number.
If you managed to get a different sprocket, it will probably have wrong number of teeth, leaving you to change yet another sprocket to get gear ratio's correct. I could give dimensions to get the simple sprocket distance piece turned up.
Joining and asking members of the pre war e group may help find the pre war 250 only sprocket. I think comp. 1938 250 has 17 teeth. this will alter RPM in gears and of course top speed. Perhaps not too much. Earlier 250did have 17 teeth. Depends what you like. Perhaps better suited for country roads and hills.
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by SPRIDDLER »

Rob Harknett wrote:Neville the bike is a 250, 350 sprocket not suitable.
Ah, that's just me being a 'sprocket and see' fettler rather than going by the book.
When push comes to shove I'll try any part in a storm and leave no turd unstoned ;)
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Rob Harknett
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Re: model 22 just pre war,- shock absorber primary sprocket

Post by Rob Harknett »

SPRIDDLER wrote:
Rob Harknett wrote:Neville the bike is a 250, 350 sprocket not suitable.
Ah, that's just me being a 'sprocket and see' fettler rather than going by the book.
When push comes to shove I'll try any part in a storm and leave no turd unstoned ;)
I have no idea about at later sprocket fitting and working OK Neville, someone like yourself may have the answer. Teamwork Neville. I think I have solved how to come by 5 out of 6 bits. But the sprocket ????????? Maybe any with 16 or 17 teeth. Dynamo seems common at 17 T for that part of it.
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