Strange frame number Cappra VB

[Kryckan]

Hallo  I bought a Montesa Cappra VB 360 1976 for tre weeks ago here in Sweden it it fitted with a 360cc ,engine number 66M0503A ,but the frame has two frame number one on the leftside of stering head(73M0001) and one on the right side (66M0502) is there anyone who knows why there is two nubers?both numbers looks like original,the engine case is made off electron/magnesium,is this used for each
VB?. Glad for response ,Kryckan.

[cappra]

In all my years of dealing with Montesa's, I have never seen a frame with two serial numbers stamped, much less 73M0001! Also, never seen a 360 motor with the letter A on the end of the serial numbers.
And, never seen a Montesa with magnesium engine cases! Is there some alternate Montesa universe that I don't know about?.........

[Hoony]

hmmm... wonder if its a factory prototype.

[jerry]

Your on it Hoony. Some sort of a "works" machine? J

[GMC]

Can you post some photo's?

[Kryckan]

I will trye to load a picture (first time for me)

[cappra]

If the engine cases are truly magnesium, that would seal it for me! I have never seen an "A" at the end of the serial numbers, but there it is. I have seen 1980 VF 414's with the letter F at the end of
the numbers. I will have to ask a friend of mine that worked at the factory in the 70's and see what he has to say. Keep the pictures coming!

[Kryckan]

some more pictures. I discovered that it was magnesium when I would weld an injury, I have welded aluminum for 20 years so I can see the man differs from aluminum and magnesium

[Hoony]

the frame # 73M0001 is very interesting. i will leave Cappra to guess on why there is 2 frame #'s

my GUESS ONLY "perhaps it was a between models prototype."

[Slakewell]

Looks Mag to me, Do you have mag Filler rods.

[Montynut]

The 73m number looks very suspect to me as all the frame numbers I have seen have been inline and spaced accurately as if the row of numbers/letter have been stamped all at once or by machine. The 73M series started back with the VR250 way back in '73 so how that number would get on to even a prototype of the VB series seems illogical


The casings on Montesa are normally aluminium although when new they have a bronze sort of colour a lot like Mag alloy in unpainted areas. If the filler rod used on the case in the photo was aluminium then the case is not Mag alloy as I would not have thought it would have taken at all.

The 66M numbers seems to indicate that it is a very early '77 model which is also supported by the rear loop over the guard. But then the frame engine mounts seem strange as the tube between the bottom frame rails at the foot peg mount seems to be curved and include an engine mount. Also there does not seem to be the three engine mounts at the front and a VB should have two engine mounts on the swingarm spacer centre section instead of what appears to be one. Those engine mounts look very much like the mounts for a VA360 set of cases which was much more like a VR/VA/enduro set of cases. Over to Jared

The front brake arm faces forward when it should face back for a VB360 although this could just be a swap with some other front wheel.

All in all it is even more confusing as you look at it

[Slakewell]

My Montesa isnt that good but are those forks right?

[Montynut]

35mm Marzocchi standard for VB montesa 38mm from VE series. Montesa even had them standard before KTM

[Kryckan]

my first attempt to weld I used filler rods MG3 but after a few seconds it snapped  to the weld and I could take the the weld with a  pliers, then I cut chants fron an engine cover from a Sachs is of magnesium, then sits weld properly
front wheel hub is probably not original

[albrid-3]

that is a 1974 vr tank