Interesting questions. In 1937, Smiths 80 mph and 120 mph speedos were listed as optional extras, for all Nortons. Not shown fitted to bikes in the brochure either.
(A brakelight, and whichever model of horn you wanted were also listed as optional extras)(As was a big long list of other extras) (A magdyno was an extra on an Inter). In 1938, what appears to be speedos are shown (fitted) in the brochure pics - but are still listed as extras. Speedos shown look like artists impressions though, and look to be about 2'. No idea of Smiths speedo model - anyone? When did speedos become a required fitment?
Smiths Chronometric Speedometer Replica
WD Nortons all? Had 80 mph Smiths chronometrics, usually with brass bezel. 1930s Nortons don't appear to have had rev counters.
The drive on the maggie drive chaincase or off the cambox is a dead giveaway, and racebikes don't seem to have them. Although one or 2 later 1930s race bikes maybe have a tacho in the pics? Nortons seem to have maintained a policy of considering the speedo to be an extra-cost option, even on UK market bikes after fitment became compulsory. This may well have been a way of reducing the 'Purchase Tax' liability which was payable on new machines but not on spare parts. It's worth asking the Norton Owners Club or the VMCC to check the records for your bike as the extras should be listed. This will include such things as 'Full PFR' (pillion footrest) / Magdyno / Panel tank etc and also whether a KPH or MPH speedo was installed.
It may indicate if this was a 120 mph instrument as I'd expect and if it had a trip meter. The clock should certainly be of the 'Jaeger' drive type (with the pin attachment and the 'thick' cable). I would think that no self-respecting Inter purchaser would choose an 80 MPH unit so probably 120 MPH, illuminated, with trip. The 30MPH bar on speedos of this era was yellow-coloured. A substantial proportion of the instruments that turn up are ex-WD (they were fitted from 1936-on) and these are 80 MPH, non illuminated, non trip so not really suitable. Hello, I have recent sold my1936 model CS1 which had instrument Panel in tank.
The wiring and speedo; judging by their very UNDISTURBED state were original, as confirmed by Norton's specification records as the previous response mentioned. This was indeed a 120MPH Cronometric (no illumination) driven from the front wheel. It did not have a yellow marker but a white one at the 30MPH level but this may have bleached over the years. It was a two owner job that I bought back from Australia.
Every other component was the original serial number as listed and shipped by Norton in Sep 1935 to Tozers in Brisbane (with the exception of the MagDyno which was from 1931). Teh speed did not work and when reguilt by Gaggs in Nottingham they confirmed its production period as 1935.
I would summise it was the original Speedo. Hope this helps.
Understanding Smith's Speedo Reference Nos Classic cars forum & vehicle restoration. Author Message TonyBrooks Joined: 02 Jan 2008 Posts: 110 Location: Maidenhead Posted: Fri Mar 09, 2012 1:03 pm Post subject: Understanding Smith's Speedo Reference Nos My present speedo reads some 20% fast - I have got round this by sticking a piece of paper over the printed figures showing the 'true' speeds. However it would be nice to get something more accurate. I know I can get the instrument recailbrated by the likes of Speedy Cables etc but I thought I would first see if there is a generic speedo which would be suitable. My present model has the following on it SN 6144 2685 1280 and I assume the final 4 figures are the revs per mile. One web site I have found suggests that the 1280 should be increased by 20% equating to 1536 - do the experts here agree? If so has anyone got a database of 100cm wide (4 inches) speedos that have a relevent ref no nearer to my ideal?
Thanks Dinalpin Berlinette (Alpine Renault A110) peter scott Joined: 18 Dec 2007 Posts: 5713 Location: Edinburgh Posted: Fri Mar 09, 2012 3:56 pm Post subject: Hi Tony, This might help: You can do minor re-calibrations by driving through these 'Your Speed' signs and noting your current speedo reading. Then turn your speedo pointer to the same speed that it was showing, restrain the aluminium disc and twist the pointer to the 'Your Speed' position.
If you have a rev counter and know your gear ratios and rolling radius you can do the same thing at a known speed. Or a third possibility is to read your speed from a sat nav. Peter 1939 SS Jaguar 2½ litre saloon Jim.Walker Joined: 27 Dec 2008 Posts: 1233 Location: Chesterfield Posted: Fri Mar 09, 2012 7:02 pm Post subject: I had such a problem when I changed the wheel size on my Gentry. Windows 10 32 bit download.
The final numbers are the turns per mile. I measured out the longest straight and level distance I could as a known fraction of a mile and marked out the start and finish. With a piece of card on the detached cable as a flag and on the new wheels and tyres carefully inflated I rolled the car over the known distance and counted the cable turns. It was easy then to calculate my requirement.
176 yards (1/10th of a mile) means the required figure is the resulting turns x 10. I was able to find a suitably marked speedometer of the same dimensions as my original in a local scrap yard. Though the original was a Smiths and the 'find' was a Jaegar the internals were easily interchangeable (identical in fact) to retain a matching dial though curiously the speedo cable threads on the back are different and I had to modify the cable end. Don't be tempted to compare your speed with the 'your speed' devices.
They can be, and often are, way off. And can be influenced by other traffic. Quote from my late Dad:- You only need a woman and a car and you have all the problems you are ever likely to want'.
Computers had not been invented then! MVPeters Joined: 28 Aug 2008 Posts: 593 Location: Northern MA, USA Posted: Fri Mar 09, 2012 9:37 pm Post subject: There have been several threads on this topic recently. Here's just one, but if you Search the forum for 'Calibration' or 'Speedo' you'll find the others. I'll just comment that I thought the turns-per-mile number was under the odometer - I don't know if it is also part of what looks more like a serial or part number. You might check with the other(!) Talisman owner & see if he also has a 1280 speedo or not. I imagine there were variations in axles etc, so this may not be much help. Send me your e-mail address & I'll send some files that have more detailed information.
Mike MVPeters at comcast.net 2002 Mini Cooper 'S' MVPeters Joined: 28 Aug 2008 Posts: 593 Location: Northern MA, USA Posted: Sat Mar 10, 2012 8:14 pm Post subject: I just came across this book about repairing & calibrating speedos on eBay: If it's any good it might be a worthwhile purchase. Mike MVPeters at comcast.net 2002 Mini Cooper 'S' Display posts from previous: - All times are GMT + 1 Hour Page 1 of 1 Jump to: You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum.
$323.58 15 Bids Sold, $30.03 Shipping, 14-Day Returns Seller: (557) 100%, Location: Pentraeth, Ships to: Europe & many other countries, Item: 23 Here we have Rare, Genuine Smiths 1930s vintage, Chronometric 80 MPH Speedometer. It has the Jaeger type drive and no facility for illumination so I suspect it could be a military type. The little alloy plate underneath this instrument is stamped with S11 5- 7- 38- which I think is 5th July 1938. Also a serial number 6834431. In good condition for its age 78 years.
The needle moves when the drive shaft is spun and the digits that indicate the mileage clock round as they should, the bezel has a few marks and scrapes, and the paint on the body has worn off in places. The knob to operate the mileage trip is missing, but the shaft it fit onto is there The body of the speedo is also stamped with Patent Numbers 222 and 275217 I would recommend it be serviced before use as it is bound to need some lubrication after all these years. All in all a very rare and difficult to find item, so get bidding! I will accept PayPal, Postal orders or cash on collection for this item, and postage for this item will be £4.75 1st class signed for. Thank you for looking Condition: Used, Brand: SMITHS, Manufacturer Part Number: S11, Country/Region of Manufacture: United Kingdom See More.
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