What does this Speedo marking mean

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 14 May 2013, 12:04 am

#955583

So got an old mph speedo to play with and wondering what the W0.8 stamped on the back means?

There is nothing to state how many revolutions per mile the speedo goes like an old Smiths gauge would so I'm wondering if this is the worm drive ratio?

Fancy playing with making it a KPH speedo as it's easy enough to screen print the dial from MPH to KPH but the odometer is the trickier part.

Ta 🙂

madness is in the eye of the beholder 👍

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 14 May 2013, 8:00 am

#955598

Your onto it, it;s the internal preset ratio

All VDO are like that so I'm sure google will tell more details

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 14 May 2013, 9:49 am

#955616

Its the code for what size tyres the speedo is meant to be fitted with.

There was a list on Thesamba about what tyres for what code, but I'm sure from memory the late Beetle 25.3" tyres was W0.51

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 16 May 2013, 12:55 am

#955834

Yea, I've been playing around with it and doing some calcs and for std Beetle tyre diameter your looking at 800 revolutions and as speedos are given in respect to every 1000 revs then the 0.8 is this ratio. Basically the last worm and cog of the odometer sets the ratio so for kilometers I need the drive ratio to be 0.5.

As for the speedo itself I could mess around with strengthening or weakenin the permenant magnet in the drag cup but trying to reprint to kph seems the easier option 🙂

madness is in the eye of the beholder 👍

bajachris88 The international telephone dialing code for Antarctica is 6

6,661 posts · joined Apr 2005 · 16 May 2013, 8:29 am

#955842

psimitar wrote:Yea, I've been playing around with it and doing some calcs and for std Beetle tyre diameter your looking at 800 revolutions and as speedos are given in respect to every 1000 revs then the 0.8 is this ratio. Basically the last worm and cog of the odometer sets the ratio so for kilometers I need the drive ratio to be 0.5.

As for the speedo itself I could mess around with strengthening or weakenin the permenant magnet in the drag cup but trying to reprint to kph seems the easier option 🙂

G'day mate, if you find a mob that does the reprinting please let me know. I'm going to be changing tyre diameters soon and it will put the whole scale out of whack 🙁

(ô_!_/ô) (ô_!_/ô)
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DylanTheDubber Custom Title Time!

1,252 posts · joined Jun 2009 · 16 May 2013, 9:36 am

#955847

I Can Re-Calibrate VW Speedos.

Im on the Gold Coast Now.

Let me know what wheels and tyres your running i can do the rest.

From Dylan

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 16 May 2013, 10:37 pm

#955933

DylanTheDubber wrote:I Can Re-Calibrate VW Speedos.

Im on the Gold Coast Now.

Let me know what wheels and tyres your running i can do the rest.

From Dylan

So does this mean you reduce the magnetism to allow the drag drum to turn slower so that the MPH scale now works as a KPH scale?
And then you change the gears for the Odometer to work in kilometers too?
If so then how much does a re-cal cost roughly?

Ta,
Mike

madness is in the eye of the beholder 👍

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 16 May 2013, 10:42 pm

#955934

bajachris88 wrote:G'day mate, if you find a mob that does the reprinting please let me know. I'm going to be changing tyre diameters soon and it will put the whole scale out of whack 🙁

Will do 🙂 Looking into how hard it is to either screen print it meself or get a stencil sticker made to re-spray the face.

For yours tho the Odometer will be out by the percentage increase in the tyres rolling radius but having the magnet within the drag drum strengthened by a gauge recalibrators would mean the dial wouldn't need repainting 🙂

So gives you the option if you wish to recalibrate instead of re-painting the dial.

madness is in the eye of the beholder 👍

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 16 May 2013, 11:24 pm

#955944

To change calibration, it's more usual to fit a gearbox into the cable, that way speedo and odometer stay in sync. Flex-drive Agencies used to do it, I think they are still around.

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 17 May 2013, 7:34 am

#955955

bajachris88 wrote:G'day mate, if you find a mob that does the reprinting please let me know. I'm going to be changing tyre diameters soon and it will put the whole scale out of whack 🙁

I'm not sure if Brent at Castlehill Gauges still does it but he made my new faces up.

They are plastic with opaque number like modern cars have so light up much better at night and he can alter the design,
I wanted that ring around the center gone on my new one and the odometer cut out as one not individual.
I'm sure changing the scale wouldn't be too hard.

cb john Wolfsburg Wizard

470 posts · joined Jun 2007 · 17 May 2013, 10:14 am

#955968

I have plenty of those in different colours and for different gauges...all the other stickers as well...

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 17 May 2013, 2:06 pm

#955987

matberry wrote:To change calibration, it's more usual to fit a gearbox into the cable, that way speedo and odometer stay in sync. Flex-drive Agencies used to do it, I think they are still around.

Now that's an intriguing idea 🙂

if not then the stickers may work but at the same time I like the early style of speedo as it has 5 lines between each number whereas the later speedos are just a plain black background with the numbers on it.

madness is in the eye of the beholder 👍

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 18 May 2013, 1:50 pm

#956078

psimitar wrote:So got an old mph speedo to play with and wondering what the W0.8 stamped on the back means?

There is nothing to state how many revolutions per mile the speedo goes like an old Smiths gauge would so I'm wondering if this is the worm drive ratio?

Fancy playing with making it a KPH speedo as it's easy enough to screen print the dial from MPH to KPH but the odometer is the trickier part.

Ta 🙂

always wondered what that was... lol

easier to have a new sticker/face made...

Lee

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---