Author Topic: black face speedo?  (Read 503 times)

Offline David Tinsley

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black face speedo?
« on: 02.06. 2023 21:52 »
55 GF SA

Started to look at the speedo which is not working. It is a black face chrono and I think it should be white? Bit of an academic question I know as it needs replacing, but there is someone in Canada who advertises repairs and I want to make sure I get the correct one.

Is there any advantage to chrono over magnetic apart from it being period correct? If the price difference is big then I would lean towards the cheaper option unless there is an advantage of the chrono over magnetic?

One last question, curiosity really. What is the large fixed line at 30mph for, with similar smaller lines on inner face with speeds that do not match the main outer dial. Guessing it is to do with max speeds per gear, but cannot figure why the inner, smaller scales do not match the larger outer one?

cheers
Dave

1955 A10 Golden Flash

Online Bsareg

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Re: black face speedo?
« Reply #1 on: 02.06. 2023 22:11 »
That looks like a speedo off a Triumph twin. Strangely, I had the same type fitted to my C11 when I bought it in 1960. I think they are quite sort after now.
Helston, Cornwall C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Online JulianS

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Re: black face speedo?
« Reply #2 on: 02.06. 2023 22:57 »
It is a combined speedo/tacho.

The inner rings marked 2nd, 3rd and 4th represent the gears and the figures in those rings indicate RPM. So for example if in 4th and the speedo needle reads 70 read off the engine RPM on the ring marked 4th.

Only as accurate as the calibration.

Offline David Tinsley

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Re: black face speedo?
« Reply #3 on: 02.06. 2023 23:04 »
It is a combined speedo/tacho.

The inner rings marked 2nd, 3rd and 4th represent the gears and the figures in those rings indicate RPM. So for example if in 4th and the speedo needle reads 70 read off the engine RPM on the ring marked 4th.

Only as accurate as the calibration.

Ah, thank you for that, it was confusing me. A bit clearer now!

1955 A10 Golden Flash

Offline trevinoz

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Re: black face speedo?
« Reply #4 on: 02.06. 2023 23:06 »
Being a Triumph speedo the ratio will not be correct for a BSA.
I went down this path over 50 years ago with the end result of a speeding fine.

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Re: black face speedo?
« Reply #5 on: 03.06. 2023 05:39 »
The thick line at 30 mph is a nod to the then-prevailing universal urban UK speed limit Dave, the rest are rpm related and for Triumph I also think. Definitely sought after by Tri-harders.

As for face colour and magnetic vs chronometric  . . . black face is pretty universal for chronos AFAIK.  Magnetics come in shades including black - and use a slightly different cable coupling at the head. Not interchangeable.

It's heresy to say it, but I have preferred the magnetic instruments on the bikes I have / have had with them (particularly for tachometers, as they react far more quickly). There is a general love affair with chronos because they are an example of the clockmaker's skill, and of course they look great and are 'right' on bikes of the day.
But the later Smiths magnetic jobs are perfectly OK if you're not bothered about originality, probably cheaper to source and certainly to rebuild. Like chronos, they can I think be recalibrated to suit gearing - but not sure by whom out your way!

The deeper-bodied dirt-cheap Indian-made lookalike chronos are inaccurate though, if it matters, and won't fit comfortably in many nacelles or headlight shells. Most people can tell within a very few mph how fast they're going, and some of us regard speedometers as the optional extra they once were so it may not matter to you. Quite a lot of people seem to put up with them on grounds of price and a reasonably close 'look'.
Bill

Offline KiwiGF

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Re: black face speedo?
« Reply #6 on: 03.06. 2023 07:28 »
55 GF SA

Started to look at the speedo which is not working. It is a black face chrono and I think it should be white? Bit of an academic question I know as it needs replacing, but there is someone in Canada who advertises repairs and I want to make sure I get the correct one.

Is there any advantage to chrono over magnetic apart from it being period correct? If the price difference is big then I would lean towards the cheaper option unless there is an advantage of the chrono over magnetic?

One last question, curiosity really. What is the large fixed line at 30mph for, with similar smaller lines on inner face with speeds that do not match the main outer dial. Guessing it is to do with max speeds per gear, but cannot figure why the inner, smaller scales do not match the larger outer one?

cheers
Dave

I’m not sure on prices in other countries but used chronometrics cost more than double magnetic type in NZ, so hang onto your chronometric as that is the right fitment for an A10 *woo* prices asked for restored chrono speedos can be eye watering.

A (specialist) repairer may decide to modify your speedo to suit an A10 (changing “ratios” to suit different drives and wheel sizes is straightforward), or if it’s easier “swap” with a (chrono) speedo closer to what you need.

I am not sure if you know what spec speedo you need, if not you can ask on here. Options include ratio, trips, lights, trip location (side or bottom) clockwise/anti, bezel type, dial face etc

The speedo model number (I cant quite read it on your pdf/pic) may give a clue to your speedo spec eg ratio, but it is not uncommon for a number on the dial not matching whats actually inside the case eg if the dial has been replaced. Nowadays “printing” of a dial is easy, but a repairer may not want to go as far as printing one with the correct smiths model number for your A10.

Does the speedo work?
New Zealand

1956 A10 Golden Flash  (1st finished project)
1949 B31 rigid “400cc”  (2nd finished project)
1968 B44 Victor Special (3rd finished project)
2001 GL1800 Goldwing, well, the wife likes it
2009 KTM 990 Adventure, cos it’s 100% nuts

Offline Jim S

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Re: black face speedo?
« Reply #7 on: 03.06. 2023 15:06 »
David
In fact there are 2 sources in Canada for repair of your speedometer.
Vintage British Cables in Medicine Hat and Spyder Technologies in Ottawa.
I have had good experience with both.
Jim

Offline David Tinsley

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Re: black face speedo?
« Reply #8 on: 03.06. 2023 15:17 »
David
In fact there are 2 sources in Canada for repair of your speedometer.
Vintage British Cables in Medicine Hat and Spyder Technologies in Ottawa.
I have had good experience with both.
Jim

Yes, I am looking at vintage british cables website. Gregg at Spyder reconditioned my mag and was very pleased with that.

1955 A10 Golden Flash

Offline David Tinsley

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Re: black face speedo?
« Reply #9 on: 03.06. 2023 15:20 »
55 GF SA

Started to look at the speedo which is not working. It is a black face chrono and I think it should be white? Bit of an academic question I know as it needs replacing, but there is someone in Canada who advertises repairs and I want to make sure I get the correct one.

Is there any advantage to chrono over magnetic apart from it being period correct? If the price difference is big then I would lean towards the cheaper option unless there is an advantage of the chrono over magnetic?

One last question, curiosity really. What is the large fixed line at 30mph for, with similar smaller lines on inner face with speeds that do not match the main outer dial. Guessing it is to do with max speeds per gear, but cannot figure why the inner, smaller scales do not match the larger outer one?

cheers
Dave

I’m not sure on prices in other countries but used chronometrics cost more than double magnetic type in NZ, so hang onto your chronometric as that is the right fitment for an A10 *woo* prices asked for restored chrono speedos can be eye watering.

A (specialist) repairer may decide to modify your speedo to suit an A10 (changing “ratios” to suit different drives and wheel sizes is straightforward), or if it’s easier “swap” with a (chrono) speedo closer to what you need.

I am not sure if you know what spec speedo you need, if not you can ask on here. Options include ratio, trips, lights, trip location (side or bottom) clockwise/anti, bezel type, dial face etc

The speedo model number (I cant quite read it on your pdf/pic) may give a clue to your speedo spec eg ratio, but it is not uncommon for a number on the dial not matching whats actually inside the case eg if the dial has been replaced. Nowadays “printing” of a dial is easy, but a repairer may not want to go as far as printing one with the correct smiths model number for your A10.

Does the speedo work?

No, the speedo does not work. I tried spinning it up with a drill and no joy. The cable is rotating so it is not that.
Looking at fitting a decent magnetic as not too concerned about absolute orginality. vintage british cable here in Canada looks as though they might take my chrono and be able to repair it but got to contact them yet. Hoping he will be able to tell me what is correct for my year and model

1955 A10 Golden Flash

Offline David Tinsley

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Re: black face speedo?
« Reply #10 on: 03.06. 2023 15:22 »
The thick line at 30 mph is a nod to the then-prevailing universal urban UK speed limit Dave, the rest are rpm related and for Triumph I also think. Definitely sought after by Tri-harders.

As for face colour and magnetic vs chronometric  . . . black face is pretty universal for chronos AFAIK.  Magnetics come in shades including black - and use a slightly different cable coupling at the head. Not interchangeable.

It's heresy to say it, but I have preferred the magnetic instruments on the bikes I have / have had with them (particularly for tachometers, as they react far more quickly). There is a general love affair with chronos because they are an example of the clockmaker's skill, and of course they look great and are 'right' on bikes of the day.
But the later Smiths magnetic jobs are perfectly OK if you're not bothered about originality, probably cheaper to source and certainly to rebuild. Like chronos, they can I think be recalibrated to suit gearing - but not sure by whom out your way!

The deeper-bodied dirt-cheap Indian-made lookalike chronos are inaccurate though, if it matters, and won't fit comfortably in many nacelles or headlight shells. Most people can tell within a very few mph how fast they're going, and some of us regard speedometers as the optional extra they once were so it may not matter to you. Quite a lot of people seem to put up with them on grounds of price and a reasonably close 'look'.

Hi Bill,
Yes, not to worried about originality and and as you say most of us know pretty closely how fast we are going and I wont be riding this bike anywhere near any speed limit! Leaning towards a magnetic
cheers,
Dave

1955 A10 Golden Flash