Replica Speedometers

[GraemeLangley]

Hi All, I have a 1934 framed, 1937 engined with a G49E49 Burman gearbox. This is clearly a 'parts' special and I am looking for a speedo to fit without having to pay a kings ransom!
Feked do an 80mm diameter smiths replica, I assume I need a burman spade drive to mate with the gearbox. Has anyone any experience of doing this and any tips for success? Thanks for any views!

[paul.jameson]

Go to your local bicycle shop and get one of theirs to mount on the handlebars. This is the cheapest and most accurate option.

The problem you face with a speedo driven from the gearbox is that the PA type used prewar (and in 1946/7) have the drive at right angles to the case ie parallel to the face. this means that the cable tunnel through the tank comes out at the back corner. The chronometric type used postwar have the drive at right angles to the base of the speedo so the tunnel through the tank goes down almost vertically. The flex speed for the PA is 2240 but for the chronometric it is 1610 so the gearing is different in the gearbox. Geoff Brown (Gearbox spares) can provide conversion kits if need be, but your gearbox should be correct for a chronometric whilst your tank should be correct for a PA. A PA speedo may cost a "Kings ransom" but should be accurate enough to avoid speeding fines. Few Kings are of help when they catch you speeding!

[GraemeLangley]

Thank you Paul

[Ian.Taylor]

I agree with Paul
I use a catseye speedo on my 31 Ariel as well as my 31 Norton both are very accurate and the Plus is I don't have to look down at my speed.On my 36 Norton I had it reading 65mph.

[Roger Gwynn]

Warning! Some cycle speedos only read up to 100 kph (62.5 mph) so are a bit slow for our high speed machines, also I have been told that wireless ones can have problems with HT interference. There are some nice ones made for motorcycles.

[dave.owen]

I've suffered with a wireless unit with a mag ,so it went in the bin, my 1927 model with an old cycle speedo regularly saw 100 kph

[jim.haydock]

Graeme,

I had the same issue when I was building my 1948VH with a panel tank. I found a waterproof GPS speedometer on ebay intended for motorcycles and boats costing about £35-. The diameter is 85mm which is slightly bigger than the hole in the panel but easily remedied. The unit stands proud of the tank by about 8mm but I sorted that out by fitting a black wrist band under the bezel to raise it up slightly above the surface of the panel.

It works well and is very accurate. On start up after being in the garage the gps takes up to a minute or so to get a fix but for the rest of the day is almost instantaneous. I wired the backlight into the tail light circuit so that it lights up red at night. It's obviously not original, but it is functional and fills the hole in the panel very nicely.

Jim Haydock,
Lancs Branch

[Roger Gwynn]

The speedos i use are made by Sigma, some are very flash and will give 0-100 mph times and many other things, a bit over the top on my 1932 side valve!