Introduction to finding your bike’s frame number
In order to verify that the number on your vehicle registration paperwork match those your bike, you’ll need to locate the frame and engine number markings on your motorbike. This is easy enough, as long as you know where to look that is!
These are not always in the most obvious location and can often be hidden from view. You might also spot one of the various ‘red herring’ casting or part numbers which may be scattered around the bike and which are often mistaken to be the frame number.
Hopefully though with the help of this article you should be able to locate the correct, unique frame number on your AJS or Matchless motorbike in order to be able to verify it against what is recorded on your registration paperwork. The frame number is also known more officially as the “Vehicle Identification Number” or just “VIN” for short.
This article contains the following sections which you can jump to by clicking the appropriate title:
- Where NOT to look for the frame number
- Pre-1958 model frame numbers
- 1958-1959 model frame numbers
- 1960-1967 model frame numbers
- Engine and gearbox numbers
- Conclusions and your comments
Where NOT to look for the frame number
There are, apparently, many Matchless and AJS bikes out there that have been registered with the DVLA using the same “016117” frame number shown in the picture on the right. On my 1951 Matchless G3LS this is stamped into the top of the front down-tube. I initially, like many other people, mistook it to be the frame number. Actually it is just a casting or part number identifier from when the frame was made and hence is identical on many Matchless and AJS bikes, so beware!
The number shown in the picture is stamped onto the frame of my 1951 Matchless G3LS on the front down-tube, just in front of tank next to the top engine bracket. The circular loop cast into the frame on the left is the front side-car mounting.
The full code reads “+016117 M&B”. As far as I can tell this is a casting number (the ‘016117’ bit) and the manufacturers name or reference (the ‘M&B’ bit) as these components were not usually made in-house by AMC. It is definitely not the frame number!
The give away is the plus sign and the “M&B” additions, whereas the correct frame number should just be numbers with maybe a capital letter prefix (e.g. “A123456”) in some cases.
On some bikes, this part number is apparently raised (rather than stamped) which would mean it was cast into the frame and so must be the same on every frame from the batch (as they will all have come out of the same mould). On my bike though the numbers are definitely stamped (indented) into the metal, but either way they are not unique identifiers.
Pre-1958 model frame numbers
For the earlier Matchless and AJS motorcycle models made up until 1957, you need to do a little ‘digging’ under the saddle to find the frame number as it is not always in easy view. It depends a lot on what type of seat your bike has fitted; it’s much easier to see if you have a single saddle type, but more hidden by the longer two-person bench type.
The arrow in the figure on the right shows roughly where you should be looking. Standing on the right side of the bike (as viewed from the seated position), look up under the saddle to the back-end of the top horizontal tube just in front of where this joins the down-tube and the seat bolts into place. You’ll need a torch and the oil reservoir tank will also no doubt be right in the way!
If your frame is rusty, dirty or has been repainted it may actually be pretty impossible to read the numbers clearly from this angle. It’s actually much much simpler to just remove the seat (especially if it’s a long dual-seat type) to give yourself a clearer view. You’ll also be able to get in there to clean the relevant section of the frame, or look from different angles or under different lights in order to be able to make out all of the numbers.
The photo on the left shows the frame number stampings on my 1951 Matchless. Hopefully this should give you a pretty good idea of where you should be looking and the sort of thing you should be looking for. For reference, you can just make out the edge of the oil tank lid at the bottom of the picture and the back end of the petrol tank on the right.
1958-1959 model frame numbers
For the 1958 and 1959 Matchless and AJS models, the frame number location moved from under the seat to a more readily accessible location nearer the front of the frame. The arrow in the diagram on the right shows you roughly where you should be looking. The frame number should be stamped onto the right-hand side of the front down-tube, below where the forks attach but just above the top engine mount.
I can’t comment on the accuracy of this diagram as I’ve not needed to find the frame number on a bike from this period yet. However, the diagram is from the same source as the one above which I know to be correct so I have no doubt that this illustration is also accurate too.
1960-1967 model frame numbers
From 1960 onwards the engine number stayed in a similar position at the front of the frame, but moved slightly with the change over to a duplex frame with two front down-tubes.
Again the arrow in the diagram on the left shows you roughly where you should be looking, and also suggests that this is where the frame number should be on all of the so-called ‘Lightweight’ models.
Like before, stand on the right-hand side of the bike and look at the right-hand front down-tube, below where the forks attach but above the top engine mountings.
Engine and gearbox numbers
Now that you have hopefully found the frame number of your classic Matchless or AJS motorcycle, the other important piece of information which you’ll probably want to check against your log book is the engine number. This is much easier to find, but like the frame number there are a few casting number ‘red herrings’ to be aware of. I have therefore written a separate article on engine numbers which can be found here.
The engine and gearboxes are separate units on the earlier Matchless and AJS motorbikes and so the gearbox should also usually have it’s own unique identifying number. Whilst this isn’t normally recorded on the registration paperwork, it may be useful when applying for a dating certificate from the owners club or if you’re trying to confirm the completeness and originality of the bike. There is therefore also a separate article available on gearbox numbers which can be found here.
Well that’s about it really; there’s not much more to say about frame numbers that I can think of! If you have a later (post-1958) matchless or AJS I would welcome any feedback from you regarding the accuracy of the diagrams above for the 1958-59 and 1960-67 models as I have not yet been able to verify these myself. Please use the form below to leave me a reply.