M31 CSR Frame Number

LancsHoppy · Post by **LancsHoppy** » Wed Jun 15, 2005 11:50 pm

Can anyone help me find the frame number on my '60 M31CSR. I've just inherited it from my father-in-law who bought it new so its known history, but I can't find the frame number anywhere. I've taken the head stock & top of the down tubes to bare metal on both sides but can only find the number "M12 02 3000". On the seat bracket is "M12 026 002". From earlier postings I believe these are the casting numbers - but in both cases they're stamped, not raised. Also clear is a makers (?) mark "THM".
Please help as I need to reclaim the reg. and need to find the frame number to do so
PS - the engine isn't stamped either - did AMC specialise in anonymous bikes?

Michael · Post by **Michael** » Thu Jun 16, 2005 7:42 am

Normally the frame number is on the right hand side of the tube which goes from the saddle to bottom (Behind the engine).

Michael

Biscuit · Post by **Biscuit** » Thu Jun 16, 2005 10:18 am

According to a sheet received from Pat Hughes, the frame no., for 1960 is on the right hand side below the head stock and just above the sidecar lug. 58-59 same but on left, Norton type frames also on left. Regarding the engine number, could it have had new cases somewhere along the line. What is on the registration document?

RogerNorman · Post by **RogerNorman** » Sat Jun 18, 2005 11:58 pm

Michael. Your advice is correct for the earlier frames - generally upto 1960 but not for the twin downtube frames.
They do vary however, having had the dubious honour of being a machine inspector for The Club for some 18 years I have seen them in various locations but on twin cradle frames normally around the headstock. Sides do vary however as does the size of the stamped letters/numbers it seems. Likelyhood is that the frame got a very generous helping of paint in its earleir life and the numbers have effectively been filled flush with paint. I know its going to be hard to do Steve but its probably going to need you to attack the paint with a wire brush or similar to bring the numbers to the surface. That said you may have an unnumbered frame. I have one in the garage that I picked up at a Jumble some years ago that has an AMC Repair Shop ticket still atached to it - surprise surprise. No number. I'm told it was done so that if you had a frame beyond repair, in the good old days you could be somewhat dishonest and restamp your number onto the replacement frame. Definately not encouraged nowadays however.

LancsHoppy · Post by **LancsHoppy** » Wed Jun 22, 2005 11:41 pm

Thanks for the advice Roger. I've wire brushed back to bare metal down both sides of the headstock and tubes to the change in tube diameters just below the sidecar & tank mounting lugs - but still no luck [:(]
I was hoping to reclaim the number before starting the restoration, but I guess I'll have to strip it completely and get it blasted to have a good look all over.
If I can't find any number, is there a procedure for obtaining an age related number if nothing else?

One bit of good news - I've found the engine number. I'd assumed it should be on the flat bit that looked right - not underneath [:I]. At least something matches.

On another subject - does anybody recommend a particular book / manual to help with restoration? I've got the handbook that came with the bike originally - but it's a bit ratty by now.