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Help identifying an old AJS

Discussion in 'Bike Reviews, Questions and Suggestions' started by Siwagod, Dec 11, 2014.

  1. Ey guys,

    Inherited an old AJS from my father in law, who got it from his father in law, who is now slightly out of his mind. He bought it new, rode it a bit, fell off it, then put it in his garage for the next few decades.
    I'm just trying to determine what model/year it might be. Have found similar looking ones on Google, but nothing that looks exact.
    Any ideas or suggestions would be appreciated. Sorry for darkness of photos, missus took em without flash.

    [​IMG] [​IMG] [​IMG] [​IMG]

  2. I'm not really qualified on AMC (Matchless and AJS, both mechanically near identical) twins, but it was a common habit of the British industry to use the first few characters of the engine number to denote the model designation.

    Based on the nature of the motorcycle market of the 50s and 60s, I'd say that it's most likely to be a 500 (Model 20), slightly less likely to be a 600 (Model 30) and highly unlikely to be a 650 Model 31). Swingarm rear suspension with fat "jampot" shocks indicates mid-50s onwards but the inherent conservatism of the British industry means there's a ~10 year window for the styling. It looks to be the "cooking" model, so it won't be the upmarket CSR or CS. Overall, my (slightly educated) guess would be a Model 20 from c1958. A decent, solid bike with OK handling, reasonable performance for its day and a general air of quality. No sporting cachet though, and no exciting model names like Tiger, Rocket, Meteor etc. AMCs road offerings of the time were generally "sensible" bikes.

    It looks in nice, original nick. Beware, though, if you ever ride it, don't overrev it. The AMC twins had a crank that, although theoretically superior to other manufacturers' offerings, had a reputation for letting go in a big way if used even moderately hard. The 500s were less prone to this than the bigger models and the factory eventually (sorta) fixed it with better materials but it's something to be a little cautious of. Scrupulous lube system maintenance should help. Unfortunately, on most original Brit twins that means a regular (would have been ~annual for a bike in everyday use) engine strip to clean out the sludge traps in the crank. A major PITA, so it often didn't/doesn't get done until the engine dies.
    • Informative Informative x 1
    • Informative Informative x 1
  3. Wow, talk about a solid reply.

    We were looking at cleaning her up, get her running, and then possibly selling. Any guesses as to what these were worth. I've heard everything from as low as a bag of potatoes, up to what can only be described as overly optimistic.
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  4. Difficult to say on value. The AMC twins are a bit niche, without the wide appeal of Triumph, BSA or Norton equivalents, and don't appear in the same numbers so sample sizes for the purpose of price estimation are a bit small. A thorough internet search is likely to be the best bet. Just beware of some dealers who equate rarity with high values.

    As a more general guide, look at what things like Triumph Speed Twins and Thunderbirds, and BSA A10 Gold Flashes are going for. An AMC twin of roughly equivalent spec should be worth a roughly similar amount (unless the market has recently gone ga-ga over them and I missed it).
    • Like Like x 1
  5. Yeah that's pretty much what I told the guy who told me it's worth a small fortune. Just because it's rare, doesn't mean someone wants it.

    I'd be thoroughly impressed if I could get anything close to what gunissan linked. My most optimistic guesses at the moment are between 5 and 10.

  6. I must admit that the big, chrome tank badge is now giving me some pause in my intial thoughts of a basic model but it's on a painted tank rather than a fully or partially plated one, so maybe not the povpack model, but probably not top of the line either. The testicle smasher rack also indicates something more than the most basic model or, at least, a buyer able to pay for a few accessories.

    But, like I said, I'm not really qualified on AMC twins as they were too rare to be a realistic ownership proposition and too staid or too fragile to be of interest to my younger, performance oriented self in the days when I gained most of what I've learned of British bikes. Dog, it was nigh on 30 years ago now :eek:.
  7. Certainly worth more than 5 or 6 these days. may even get to double figure, as people are getting a bit stupid with classic stuff.

    If you offered it to me at 6.5 i'd be tempted and i'm not overly nostalgic. You can't get many running brit twins for that anymore. And I like the fact it's not a triumph.
  8. Yeah, but not every set of Triumph crankcases in the universe has a hole in it you can put your fist through. They just leak like they do ;).

    Seriously though, on values, it's a nice barn-find which would probably have more bearing on its value than make or model. There just ain't that many unrestored, unmesed with bikes around any more and therein lies any rarity value it may have.

    However, as noted above, unlike their singles, which had a fine reputation in all areas of competition, AMC's twins were never outstanding in anything. They never had the image of any of the other manufacturers' products, Triumph's style, BSA's naming talent or Norton's legendary frame. They were decent, workmanlike bikes, but not the stuff of teenage dreams, which tends to be the main initial driver of classic vehicle price inflation. I suspect their lack of excitement (even the sporting CSR varieties were mechanically rather conservative, relied on acres of chrome and, in the eyes of many, looked a bit clumsy and odd) probably balances out their lack of abundance, hence my suggestion of similar values to similarly equipped touring spec Triumphs and BSAs (Norton values having gone a bit daft a long time ago).

    Like I said, though, its originality is a rare thing, which might give it a boost.

    Me, I'd keep it.
  9. SiwagodSiwagod head on over to pistonheads and hit up SROB, he's a total expert with old bikes.
  10. Model 31 650 as confirmed above, and probably 1961-63 as it has AMC Teledraulic forks and rear hubs. My 1964 (which didn't blow up despite some spirited use back in the 1970s) had Norton Roadholder forks. My bike was ex-NZ Police and had a painted tank. This one might be ex-cop as well, but I'm not sure if Australian police fleets used AMC bikes. What's it's engine number?
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  11. I stand corrected. Maybe there were so few 650s in the UK where I gained my impression of production numbers 'cos they all went to the Colonies :D.
  12. I had a 600 twin Matchless, Very similar to the one you have, It dropped the big end and the rods came out through the barrels,
    One very dead motor,
  13. Nothing to worry about. They all do that sir.
  14. Seriously, though, if I remember my long ago readings correctly, the 500s weren't too bad in the crank department as they weren't highly stressed. The 600s were worse, putting bigger loads on the bottom end, and were the main culprits for the weak reputation. By the time the 650 came along the factory had acknowledged the problem and were working to fix it. I suspect that the introduction of the desirable nodular iron ("noddy") crank would have been at about the same time as the motor grew the extra 50 cc. So of all possible examples, a late 650 (and given that Matchless/AJS were an early casualty of the British industry c1967, a 1961-63 bike is "late") is the most likely to have a good bottom end.