Author Topic: Chronometric Speedo Model ## needed for a 1962 BSA  (Read 2753 times)

farducci

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Hey Guys, brand new to the forum here.

Been searching old posts, but can't find the info I need.

Although I'm technically in the wrong forum with this, I thought maybe someone could help. I also have a '51 Golden Flash and a '63 RGS Scrambler I'll be getting to someday so more A10 questions to come!

Right now though, I'm working on an early 1962 BSA A65 Star which also ran a Chronometric Speedo. Is it the same as a A7's & A10's like the Super Rocket or RGS? I do have the following info (below), but was wanting to confirm this with someone for certain. Also, does anyone know if the A65 used the Same Headlight Nacelle as the A7/A10 models of the same year or if it is unique to the A65 machine?

------------------------------------------------
Grey Face Chronometric
A50 1963/1964 A65 1962/1963
Part number on face is SC 3313/00  1512
------------------------------------------------

Thanks in advance for any help!

Ryan
(Farducci)

Offline flashblack

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Re: Chronometric Speedo Model ## needed for a 1962 BSA
« Reply #1 on: 20.01. 2010 09:23 »
Hello Ryan, and welcome!  That`s quite a collection of bikes you have there!
 I can`t help you with the speedo question, but i think the A65 nacelle`s were different from the A10 one`s, as they had two switches on the left ( light switch and ignition switch) .
   I`m sure someone here can help with the speedo.    regards Rich 
build it, ride it, live it!

Offline Beezageezauk

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Re: Chronometric Speedo Model ## needed for a 1962 BSA
« Reply #2 on: 20.01. 2010 19:10 »
Hi Ryan and a warm welcome to the forum from me also.

As Rich suggested the A65 nacelles differ from the A10's due to the reason he gave.

The A10 or A65 speedo itself should fit into either nacelle but I reckon you would get an inaccurate reading if the wrong one was used.  This is because the A50 and A65 models used 18 inch rear wheels in 1962 compared to the 19 inch rear wheel on the A10's.  However, if BSA changed the A50/A65 gear ratios to compensate for this then yes, it might be ok.

Unfortunately I've never been any good at working out the mathmatics of gearing but apparently there are some numbers on the speedo faces that equate to the number of turns of the rear wheel to the mile.  No doubt there will be others on this forum who can clarify this and maybe advise further.

The correct speedo for the nacelle models should have a "Trip Adjuster Cable" about 5 inches long attached to the rear of the speedo body. If you did end up with the wrongly geared speedo head the worst case scenario would be an inaccurate speedo.  Could you live with that??

Beezageezauk.   

Offline Beezageezauk

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Re: Chronometric Speedo Model ## needed for a 1962 BSA
« Reply #3 on: 20.01. 2010 20:53 »
Ryan,

Here is some information that I've found.  The sheet states that the following Speedo Face Numbers are for USA Export Models.  I don't know if they are the same for the home market or indeed for other Export Models.

1958-60 Super Rocket     SC3305/04      120mph.
1959 Super Rocket          S.546/3/N       120mph.
1962 Super Rocket          SC3305/04    SC5301/22     140mph
1962-63 Rocket Goldstar  SC3305/04    SC5301/03     120mph
1963 Rocket Goldstar & Scrambler  SC3305/04   SC5301/23   140mph

This probably doesn't apply to your requirements unless any of the above models had nacelles fitted.

Beezageezauk.



farducci

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Re: Chronometric Speedo Model ## needed for a 1962 BSA
« Reply #4 on: 21.01. 2010 05:28 »
Thanks all.

Beezageezauk - Yeah... that's one of the same lists I have for Chrono's, which was exactly what led me to my question. Being that the A65's were driven by the Tach drive on the rear wheel, I thought they may be of different ratio's than the gearbox driven Pre-Unit Chrono's.

So it looks like the following info I have may be correct.
-----------------------------------------------
Grey Face Chronometric
A50 1963/1964 A65 1962/1963
Part number on face is SC 3313/00  1512
------------------------------------------------

Thanks for the info on the Nacelle as well. I've seen them advertised as fitting both A10/A7 & A65, but while they may fit, they are different as I suspected. Of course, the A65 version seems to be even rarer. Isn't that a surprise ;)

Thanks again all.

Offline Beezageezauk

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Re: Chronometric Speedo Model ## needed for a 1962 BSA
« Reply #5 on: 21.01. 2010 21:24 »
Hi again Ryan,

OK, I've made some enquiries with a mate of mine who has a 1962 A65 Star.  He reckons that the speedo on his bike is the original one and describes it as having a slate grey face with the number SC3313/02 and 1260 below that.

This tells me that the rear wheel does 1260 revolutions to the mile.

Beezageezauk.