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? 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.
I started by spinning a spare speedometer drive in the lathe with the original mechanical cable and speedometer attached. I set the indicated speed at 30 mph. The lathe is electronically controlled so the speed can be set precisely. When I connected up the electronic speedometer I followed the instructions contained in the set up.
This got the needle moving. I ended up with a value of 1655 which gave precisely 30 mph and 40 mph which corresponded on double checking with the mechanical speedometer to be spot on. Wiring of the electronic instrument is straight forward and is covered in detail in the instruction leaflet. Basically two wires go to positive and two wires to negative, either of which can be switched. Two wires go to the transducer and a brown wire goes to a small momentary push switch connected to negative.
This push switch does all the functions and calibration. So holding in the push switch as the ignition comes on the display will say SETPPU. Keep holding the push switch in and the display will change to six zeros. This is shown in picture one below and picture two below. QUICK SETUP GUIDE. Hold in push button and switch on ignition. Keep push button depressed.
Needle will sweep dial and display shows SETPPU then show six zeros. Release push button. Zeros will blink in turn starting at left. To set the number you require press the button repeatedly on the zero that is blinking.
When all numbers are set the display will blink. Press push button once. Display will say DONE for a moment then say SETPPU. Switch off ignition. Finished, all calibrated and set.
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. 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.
Many people consider changing the tyres on their cars to a lower profile than the standard 185's. Reasons vary from 'it looks better' to 'they cost less' the later being particularly true. The cost of a Michelin 185VR15 is about?200 and Vredestein?95, whereas a modern Pirelli P6000 205/65 VR15 is about?55 fitted (avoid the P4000!).
Given the tyres need to be changed every 5 years, regardless of mileage and wear, there is plenty of incentive to move to the newer and more available product. If you go down this route you really should have the speedometer re-calibrated and you will need to do the following.
Disconnect the flexible drive from the speedometer 2. Make a cardboard 'arrow' and press on the end of the inner cable 3. Jack up one side of the car, put blocks on the other wheels, gears in neutral 4.
Mark jacked rear tyre with chalk line or masking tape 5. Mark body with masking tape corresponding to the mark on the tyre 6. Turn driving wheel exactly 20 times while an assistant counts the number of complete turns the cardboard arrow makes, to the nearest 1/8 of a turn 7. Note make and size of tyre. Speedograph Richfield will do the re-calibration for you (they operate a mail order service) and they will need: a) The number of turns of inner cable for 20 turns of the drive wheel e.g. 13.75 b) Make and size of drive wheel tyre e.g. Yokohama TWI 205/65/15; dia.
647mm c) Make and part number of speedometer e.g. Jaguar E-Type, SN.6322/09A; C25190 d) Is car fitted with a limited slip differential e.g.
Yes A tyre size calculator is available here: The chronological age of any tyre can be found on the tyre sidewall by examining the characters following the symbol 'DOT'. For tyres manufactured after the year 1999, the last four numbers identify the date of manufacture of the tyre to the nearest week. The first two of these four numbers identify the week of manufacture (which range from '01' to '52'). The last two numbers identify the year of manufacture (e.g., a tyre with the information 'DOT XXXXXX2703? Was manufactured in the 27th week of 2003). For tyres manufactured prior to the year 2000, three numbers instead of four indicate the date of manufacture. Also, during the early 1990?s, Continental added a triangle (◄) to the end of the character string to distinguish a tyre built in the 1990?s from previous decades.
Smiths Chronometric Speedometer Application
(e.g., a tyre with the information 'DOT XXXXXX274◄? Was manufactured in the 27th week of 1994). Any tyres (including the spare) with a DOT number earlier than XXXXXX1603 should now be changed regardless of mileage - 5 years is the maximum age. You should also be aware in the event of an accident any tyres beyond their recommended expiration date, or of the incorrect speed rating, could be grounds for voiding your insurance claim - regardless of the speed you were traveling at the time. All E-Types must be fitted with V rated tyres (149mph). I have seen many cars fitted with H rated tyres (130 mph) but as Jaguar made great claim as to the E-Types maximum 150mph speed these are deemed 'incorrect'.
Worth checking if you are buying a car - good grounds for reducing the price! There is a pressure rating on the sidewall e.g. 44psi - this relates to the maximum pressure the tyre should be inflated to - not the running pressure (typically 32-34psi for an E-Type). In the UK you can be fined and your licence endorsed for each tyre that fails to comply with tread, pressure, speed rating and age recommendations. It is no excuse to say 'I only ever drive at a maximum of XX mph'.
Always pays to be nice to the Policeman if you are stopped for any reason! I found the table below in the Jag-Lovers archive detailing speedometer serial number, turns per mile, axle ratio and tyres. You will see Jaguar produced a wide range of speedos for various applications. The list is missing some TPM figures so if you have one of the listed speedometers and can provide the TPM figure (will be on the right hand side of the needle boss) I will include them. Apologies for the lazarus post here: SN 6322/08; 678; 2.93; kph (Germany/Italy) SN 6322/09;1120; 3.07; mph The speedo on my car says: SN 6322/08;1120 and it's a UK car with mph Are the records shown above in the post above incomplete? My speedo bounces around erratically, I intend changing the cable but am waiting until I swap the gearbox out.
Smiths Chronometric Speedometer Serial Numbers
I have noticed that it is fairly consistently 10mph low at the highest point of its inflection though so I'm not convinced something isn't amiss twixt speedo & diff.
Most of the WD Nortons were provided with speedometers made by Smith, with a maximum reading of 80 MPH. (numbers given on the number plate are: S.433M or S.433B/EX or S.434B/EX). These speedometers work on a chronometric principle were speed is measured in small increments instead of continuous movement. The intermittent movement of the needle therefore does not indicate a problem, its just how the instrument works.
Speedometers used by the military were not provided with trip counters or internal lighting provisions. Pokemon leaf green egglocke rom download. Those gadgets were reserved for the civvy market. Norton Assembly book entries specifically states '80 MPH Speedo, without trip'. Two types of speedometer to cable connections can be found, the early one with a round protruding shaft (referred to as Jeager drive) and a later one with an internal square connection.
It is not clear yet as of when the early Jeager types were changed to the later types. Pictures of bikes from contract V7353 still show the thick cables, which date them at least upto end of 1940, and possibly even later than that. The speedometers are actuated through a flexible drive.
These also come in two variations, each fitting to the specific connection on the speedometer. The Jeager drive cables consisted of an approximately 3 mm diameter inner flex which ran through a rubber covered steel outer flex with a.
Mm 11 inner diameter. The picture shows the Jeager type (large diameter) cable/connection.
The later cables are basically modern cables as still used today. The bottom part of both cable types consists of a spade like protrusion which is fitted in the gearbox and secured with a nut. The top part of the cable is either a tube, fitted over the Jeager drive or a square deformed end of the inner cable which slides up into the speedometer connection and screwed tight. The length of the earlier cable is not available at the moment, the later type is 25'.
The front wheel is provided with a gear ring (42 teeth) screwed onto the hub of the front brake drum. A gearbox is fitted to the front brake plate provided with a pinion (14 teeth) meshing with the gear ring. Speedo gearboxes can be found with different gear ratios and different rotation direction.
The output drive has to be clockwise when looking from above into the slot. (Rotate pinion anti-clock).
Three (3) turns on the pinion gives two (2) turns of the inner cable. Smith indicates this as 8: 12 gear ration in their folders. Early motorcycles had a centrally mounted Speedometer. The earliest contract (based on pictures) showing a left hand mounted speedometer was C6127 of which the first bikes were delivered in May 1940. The spare parts list for this contract however still refers to the centrally mounted part number 3884. The spare parts list of V7353 shows the left hand sided mounting (spare part no.
4114) superseding the centrally mounted version. This more or less indicates that at least all bikes with frame numbers above W26000 were provided with the left hand mounted speedometers. Early type of holders were all of constant width on the horizontal mounting.
This was later modified with a wider section at the left hand grease nipple/mounting bolt. Despite its apparent water tight appearance, these instruments do collect water inside.
Drying out can help prevent damage to the internals. As can be seen in the picture, my milage drum has suffered from corrosion, and I did once repair a malfunction by cleaning and drying out the inside. The shows how to execute a revision/clean up of this type of speedometer. 80 MPH smith chronometric Speedometer front wheel hub gear box Speedometer, early model 'Jeager' type connection inner cable sliding over protrusion and outer cable sliding over the housing and clamped tight with a strap Speedometer later model with internal square and screw on outer cable.