1950 Model 18 - New Owner

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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ajscomboman
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Re: 1950 Model 18 - New Owner

Post by ajscomboman »

Rob Harknett wrote:The road model frame and engine numbers were shared with other models also AJS & Matchless. So 350 / 500 / AJS / Matchless all using the same series. You cannot even guess how many 500 Matchless were made. 4778C is a 1955 model completion frame number, first year of the full width conical full width hub front and back. In fact that full width hub rear wheel was only used that year. You cannot see any difference. Inside it had metal pins in metal holes, no rubbers.
Just another note of advise. You have a time limit of free access to the club forum etc. I may consider it worth joining the club, you will then have a full year of the club benefits and the members, to help you get to know about your bike, what you have etc. Probably save you money if you need parts. Also hints and tips working on your bike.
Only road models used the steel pin hub in 55 all comp models used the bolted drum/hub.
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Rob Harknett
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Re: 1950 Model 18 - New Owner

Post by Rob Harknett »

ajscomboman wrote:
Rob Harknett wrote:The road model frame and engine numbers were shared with other models also AJS & Matchless. So 350 / 500 / AJS / Matchless all using the same series. You cannot even guess how many 500 Matchless were made. 4778C is a 1955 model completion frame number, first year of the full width conical full width hub front and back. In fact that full width hub rear wheel was only used that year. You cannot see any difference. Inside it had metal pins in metal holes, no rubbers.
Just another note of advise. You have a time limit of free access to the club forum etc. I may consider it worth joining the club, you will then have a full year of the club benefits and the members, to help you get to know about your bike, what you have etc. Probably save you money if you need parts. Also hints and tips working on your bike.
Only road models used the steel pin hub in 55 all comp models used the bolted drum/hub.


Yes Rob. I overlooked we are dealing with wheels in a 55 compt. frame in which the wheel was not QD. Which I only found out when my 64 650 CSR got a puncture which was non QD. At the Alternative rally at North Weald not so long ago. Very grateful indeed I was, for your help when you saw me struggling, to get the wheel out and tyre off
iya0yas
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Re: 1950 Model 18 - New Owner

Post by iya0yas »

Clive/Rob, many thanks to you and everyone for the info. I've learned a quite a lot about my AJS within the last 24 hours and am eager to learn more. I'm thinking I have a 1955 Competition Trials Bike (Model 18CS?) with a 1950 Engine or (the bottom end of a '50 mill) that's been converted to a touring machine....

Rob, thanks for the formal invite to join the club - consider it done...!

Summary:

- Frame: No. 4778\c = 1955 Model 18CS - Competition Trials {what does the no. +016117 M&B on the down tube refer to?}
- Engine: No. 14856 or the 2,356th 500cc engine built in 1950 out of 3,190 engines (?)
- Transmission: No. GB4 J52 = 1952 {what do the no's. 929 & 496 stamped on the housing refer to?}
- Front Wheel: 1954, 1-year only square finned full width front hub
- Rear Wheel: Cotton reel rear hub, last used in 1954 - Note the double bead lock
- Magneto: Model SR1, Type L2 1955 s/n: 42294A
- Jampots: 1955/56
- Front End: Competition bottom yoke with through lock stops - I assume this is original fitment for the competition frame?
- Final Drive Sprocket(s): Not std. equipment - Outer = 54T, Inner = 42T (Primary = 20T)
- Carburetor: Amal Monobloc no. 389 (Correct for a 1955)
- Alloy Cylinder Head: Letter "D" or "O" embossed on the head?
- Iron Cylinder: No. 013843


Additional questions:

- What battery is recommended (to be sourced from within the USA...)
- Is the Headlight Dip Switch original or aftermarket? Either way, it needs to be replaced...
- Perhaps the fenders are correct for a trials bike?
- Maybe this was a factory bike??
- I'd expect a trials specific exhaust (high/scrambler pipe) for a trials v. street model...am I correct in this assumption?
- Note the extensions on both sides of the lower frame members with a clevis joint; are these interface points for a sidecar hack?
- Final Drive Sprocket(s): Perhaps a factory accessory for off-road use?
- Does anyone have a photo of a 1955 500cc AJS Trials bike?
Last edited by iya0yas on Fri Feb 10, 2017 3:34 am, edited 3 times in total.
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dave16mct
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Re: 1950 Model 18 - New Owner

Post by dave16mct »

The 016117 M&B is a part or casting number. It's often mistaken for the frame number.
Dave.
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saltbox alf
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Re: 1950 Model 18 - New Owner

Post by saltbox alf »

The lower frame ext is for pillion foot rests, the exhaust should curve over riders foot peg. The fenders , or as we say 'mud guards' look like CSR alu types and Here is a 1950 picture I hope!! Well similar! What you have is pretty neat so enjoy :beer:
matchless_g80cs.jpg
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Allons-y, amis de Matchless et AJS
iya0yas
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Re: 1950 Model 18 - New Owner

Post by iya0yas »

That's one sharp looking machine! I like the Black paint scheme in contrast with the alloy fenders, chrome wheels & exhaust. Speaking of exhaust, I've decided to replace mine with a Competition style exhaust and install trials type tires to achieve the 'original look' of the bike.

Ideally, I hope to use my current silencer but would like some advice on which head pipe to select. Are the exhaust port angles, location, etc. the same on both '50 & '55 engines? Also, can anyone confirm which of the following head pipe options I should specify?

Option A:
http://www.feked.com/ajs-matchless-exha ... 51-on.html

Option B:
http://www.feked.com/ajs-matchless-exha ... 56-on.html

As indicated by "saltbox", the exhaust should curve over the rider's foot peg however I'm not sure if having the 1950 engine will dictate the use of Option A - I prefer option B. Thoughts, feedback...?

As for the tires, I found Dunlop D803 (90/90-21) for the front but no luck with a D803 (4.00-19 or equivalent) for the rear. I'd prefer not to use age-hardened vintage/period tires so perhaps there's a modern option I can source from England. Any suggestions here...? Thanks-
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GOLDSTAR
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Re: 1950 Model 18 - New Owner

Post by GOLDSTAR »

was that engine still extant in 1950, jampots and the lack of a front stay?, not being picky just intrigued, certainly does look good though. kind regards
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dave16mct
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Re: 1950 Model 18 - New Owner

Post by dave16mct »

Try Mitas tyres, you can get the trials type in 3.00x21 and 4.00x19.
Dave
iya0yas
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Re: 1950 Model 18 - New Owner

Post by iya0yas »

dave16mct wrote:Try Mitas tyres, you can get the trials type in 3.00x21 and 4.00x19.
Dave
Thanks Dave... I like the E-05 design.
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1957M30
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Re: 1950 Model 18 - New Owner

Post by 1957M30 »

Hi Stephen

looks like we may have twins...... :lol:

I recently became the new keeper of this Red Rocket and have just found out that if was built by non other than John Trant........
the founder of this Club.
He has been kind enough to send me a pile of photos etc. of the bike from when he first built it about 20years ago as a 350cc single,
then he replaced the lump with a 600cc Twin but I still want to fathom out if its identity, the frame is 1957 AJS as is the engine.
I am not concerned with the rivet counters that seem to belittle many of the mongrel/hybrid bikes as far as I'm concerned
thay are to be riden and enjoyed and thus they are keeping british motorycyling going strong.

good luck with your project......it looks damed good to me
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