BSA Parabike with odd serial number

[Le Prof]

Dear All, 

I'm just starting on my third Parabike restoration. Photos below show that it is missing all the usual parts, but it is an early second pattern with its original SCC2 Brown paint, and all of the transfers in good condition, so it's worth taking some effort on it.

The BSA transfer seems to vary, I have originals in both Silver and Gold? 

The oddity is the serial number. I've always read and been told that they start with an R. This one does not, it starts with a T. It's plain from the photo and comparison with my other bikes that this is not a light or mis-stamping of an R.

For comparison, here is Martyn Hillyard's in post one of his Parabike restoration:

Has anyone seen another with a T serial? Being an early Brown colour, there are R serials before and after it. 

I have a couple of ideas, but would be interested in any theories as to why it is stamped T.

And, whilst I'm here, leads to spare parts welcome, especially a replacement top butterfly nut and screw. (-:

Thanks,

Adrian

Edited September 4, 2018 by Le Prof
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[Le Prof]

Hi All,

Nearly a month and no responses? I'm surprised, due to the wealth of arcane knowledge on the site (-:

So, I'll float a theory for you to shoot at.

Bicycle manufacturers commonly used the frame code to date their bicycle to year or even month of production (I worked out the dating system used for US Columbia G519 Military bicycles which you can see on other websites, which dates to month of manufacture).

The serial number system for BSA bicycles is not currently known, and I cannot find enough known date examples to start to decode it. However, it is known that 'Parabikes' started manufacture in 1942, probably at R1, and just counted upwards into the R70000's by end of production in 1943.

Using letters for date codes, it is common to omit I, O and S, since they resemble the numbers 1, 0 and 5 (Seiko cleverly date their watches by month 1,2,3,4,5,6,7,8,9,0,N,D, so the 0 is for October!). Perhaps in January 1943, the person stamping the frames realised that, since it was a new year, it was normal to start a new letter block for frames, not S, the natural follow on from R, for the reason of possible confusion given, but T. They then continued stamping frames for a short until someone confirmed that there should be no letter change foe bikes on this contract, so reverted to R.

Sounds far fetched? I agree I will probably never know, but here are two supporting pieces of information. The US Columbia G519 bicycles were were produced from late 1941 to early 1944. In 41 the year code was F and in 42, G. 43 and 44 should have been H and I or J. In fact all army military contract bikes remained as G for 42-43 (with an M for military stamped in front). When normal production resumed in 45, bikes were coded J. Hating to quote myself, details are here:

https://thecabe.com/forum/threads/westfield-frame-numbers-1939-1945.100742/

The Germans had a similar problem with a maker of rifle magazines who had produced MP43 mags in 43, and MP44 mags in 44, stamping their mags MP45 for a short period in 45, before reverting to MP44 again.

http://claus.espeholt.dk/mp44.htm

If you've got this far, thanks for persevering. I would be interested in other ideas, or other BSA parabikes stamped T. If the idea was correct, it would show us where production was at the end of 42, not currently known.

Or perhaps it's just a mistake (-:

Best Regards,

Adrian