G2 Speedo

[cherrymetal]

Hi all,
I've just taken delivery of a couple of pretty battered smiths magnetic speedos for my G2 (the 60mm ones).

Can anyone tell me exactly the right one for the G2? One of them says 1680 on the face just below the needle and X.80421/25/2 at the top of the face above the '40'.

The other one says 1590 on the face and X.80421/19/2. They were both listed as AJS Matchless ones but I realise they could be from anything of the era, since I can't find an actual Smiths model number on either.

If someone could post a really good closeup pic of the speedo on their G2 that would help, mines a 1962 (actually I think its late 1961).

Cheers all

[Rob Harknett]

It will be a black face 100mph speedo with trip milage, well they are on my bikes. I'm sure have seen 80 mph and also without trip milage.
Look for the number just above the trip milage for 1961 G2 SM 3153/83, 1962 SM3170/22 info from Smiths cat.
I would not bother too much about the correct number, they all look the same apart from the little number other models and years also AJS all look the same on my lightweights, all have different numbers. The bezels are crimped on & very difficult to remove. Even more reason not to attempt opening them up and just changing the numbers. If you really must, scan the old bezel, change the number using photo shop to the correct number, print out the altered scan, apply a few spray coats each side with clear acrylic spray. Stick over the old face. do this also with any speedo. I have a few scans of correct faces for various speedo's, smiths 8 day clock etc, but never bothered to alter any of mine. Few will look to see if your speedo has the correct little number,

[paul knapp]

The 1680 and 1590 that you see on the dial refers to the number of drive cable turns there are suposed to be in one mile for that particular speedometers calibration. You could work it out to find which meter is more suitable to your bikes gearing by measuring the number of turns your wheel will rotate in one mile against the number of turns in the cable. (do this over a known shorter distance)
But, who's rivet counting?, they appear to be pretty close and would give a close indication to the speed/odo you are doing.

[cherrymetal]

Both mine go up to 80mph, I've seen up to 100mph on a G5, but none of them have trips on them. Is it right that the 1680 and 1590 will be matched to the speedo drive?

[cbranni]

Hi Geoff.............gut feeling says the 1590 is for 18" wheel and 1680 for 17" (G2 wheel), the number relates to wheel turns per mile, these sized speedos were used on quite a few makes of bike including James, Fanny B's. and Norton 250s I think. As long as it works it don't really matter how accurate it is.
Colin

[Ozmadman]

The bezels are crimped on & very difficult to remove.,

On the above point, my speedo is good but the bezel is crap and it steams up sometimes. Does anyone know who can replace the bezel and seal ans is it really too difficult to do yourself?

Paul

[Ozmadman]

To "Stuoyb"

Could you post your reply on here or send me an email as I am not allowed to read or send pm's due to the fact I am not a full member.

[Rob Harknett]

Paul, Its very unlikely you would remove the bezel without distorting it. When removed how would you get it back on again? Unless you have the specialist tools to do the job, get the bezel replaced by a specialist, if you can find one for that type of speedo.
Also you could still expect it too mist up.