Author Topic: BSA C15 Frame ID  (Read 2022 times)

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Caddy

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BSA C15 Frame ID
« on: 24 July, 2017, 11:39:14 »
Hello

Somehow through some late night eBay action I have managed to buy myself a BSA C15, or more correctly a pile of parts that were due to be made into a pre 65 Trials bike. I usually mess around with early Japanese bikes and some Harley's and have never built a British bike and this looked like an enjoyable project.

The frame is this pile of parts was supposed to be a BSA C15T but I'm not 100% sure if this is correct. The start of the frame number looks a bit dubious as it is stamped what looks like C15T which I don't think exists (although the model number does obviously), but the number falls in the correct range for a 1965 C15 Trials frame.

Some pictures of the frame are below and if anyone could tell me if this is a trials frame it would be much appreciated. Also was it common to re-stamp frames and frame numbers? I would like to get this bike registered for the road and I presume this frame number may cause an issue. I can show a picture of the frame number but wasn't sure if this was good idea on the internet? Please let me know if this is ok and I can post a picture.

Thanks for any help  :)


MOONSDRIFT

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Re: BSA C15 Frame ID
« Reply #1 on: 24 July, 2017, 12:47:37 »
Was it usual to restamp the frame number? Well the one I have looks like it was 'scratched' on by a child! Good luck with DVLA and getting it registered, I have been waiting 39 weeks now.

JulianS

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Re: BSA C15 Frame ID
« Reply #2 on: 24 July, 2017, 12:50:55 »
I would have expected a post 1963 C15T to have a welded frame not a bolt together one, with a number which started C15C.

Altering frame numbers on bikes is the same as altering the vin number on a car - commonly to hide or disguise its identity and/or to forge a new identity.

Photo below is from the 1965 US catalogue. You can see what the frame looks like.

Caddy

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Re: BSA C15 Frame ID
« Reply #3 on: 24 July, 2017, 14:55:37 »
The circular piece of steel in the down tube and the bend in the seat rails near the top bolt look non-standard as well. Could this be a B40 frame or part of one?

MOONSDRIFT

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Re: BSA C15 Frame ID
« Reply #4 on: 24 July, 2017, 16:19:20 »
It has been suggested that following an accident or damage a new frame supplied by a dealer may have been used and these frames were not numbered by the factory, the dealer stamped a new number.

This was suggested because I could not believe how 'amature' the frame number looked on my C15.

JulianS

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Re: BSA C15 Frame ID
« Reply #5 on: 25 July, 2017, 09:10:23 »
A new from factory replacement frame should have been stamped with the original number ofthe frame it replaced.

The problem with this particular frame is that the number used sounds like it is not from a BSA series which will make it hard to date for registration purposes.

jradcliff

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Re: BSA C15 Frame ID
« Reply #6 on: 04 October, 2018, 12:30:02 »
John R,

C15T frames were manufactured in both the early 'swan neck' type and the later Victor type. I have an ex-works bike bought many years ago from a friend in the Silsden clan. The engine and frame numbers are correct for year according to the original log book.
However the gearbox has GB40 internals that have been modified to fit by reducing pinion widths because the internal width of the box is narrower in the early crankcases.  The gear thicknesses have been modified by grinding the end contact faces. The distributor type points assembly has been replaced with the in-timing case type and an early capacitor discharge type ignition system was fitted. (Now Boyer)
The front fork looks standard but has the late double damped internals. The frame is 'Victor' pattern, not Swan Neck as it should be for the year of manufacture declared. Both wheels have Bantam hubs rather than the larger B and C series fitted as standard.
Both frame and engine numbers are correct in accordance with the registration number in the BSA factory sequence.

I am currently doing a rebuild because my son loves riding pre-65 on his C15s, and would like to ride next years Scottish Pre-65 on a real bike that has already done the Scottish at least four times when a factory mount. The bike was 'on-loan' to a number of the BSA 'Trials' dealers in it's early life and has probably been to Scotland more and was certainly used in many local and national trials. BSA eventually retired the bike in the mid-70's.

All the bits in the bike are genuine BSA, (including the seat pan which is from a C15S), but what I think this shows is that if the original declared owner of a bike was the factory, take it to  pieces and check everything in the build very carefully, because what you have is very unlikely to be standard and may have some one-off mods, viz my gearbox.

John R