I am rebuilding a 1961 ES2 and the two speedos which came with the parcel of parts are:
1. Smiths Green Circle 150 mph(!) SSM 3001/02 1000
2. Smiths Grey Circular center 150 mph(!) SSM (5001/06 1000)?
The numbers on 2. are indistinct, maybe wrong.
I think that neither are correct for the bike.
I assume the speedo drive is 2/1 but haven't checked it yet.
Can anyone tell me what I should have, and how far out these will be.
Hello, The Smiths motor cycle equipment info for 1961 I have gives the speedo number as
SC.3303/17. The same speedo was also fitted to the model 50, 88 and 99 for this year. The gearbox number is BG.5330/257 again applicable to all models as was the length of the speedo cable at 5ft 7 1/2 inches. Hope this helps, Phil
Thank you for this Philip, so the two I have are not correct for the bike, as I thought.
Does your catalog give any information on the ratio of the speedos, i.e. number of cable turns per 0.1 of a mile?
If so, are either of my two also given? In other words, can one of the two I have be used with reasonable accuracy?
Thanks again for your help.
My parts list shows that the speedo for all models in '61 except for 650 models should be:
p/n 19364 and it is shown to be for 120 mph
On my '61 Model 50 the speedo shows as SC3303/17 and 1548
I believe that the 1548 refers to the turns per mile.
Thank you for this Mike,
It looks like I am going to have to investigate further.
Diameter of rear wheel, number of turns of wheel for 1 mile, gearbox ratio (2/1), number of turns of the cable for 1 mile.
This will tell me how far out they are, if they can be used.
The green blob speedo is from an early Commando and the other looks like those fitted to Triumphs T120/T150 from the mid 60s - both magnetic and use 15/12 speedo boxes - if the Smiths speedo part number has 1000, it uses 15/12 - if the number is 1600 it uses a 2/1 box
My Smith's catalogues from 1960-1963 list the speedo for all models except Jubilee, Manx and Nomad models as SC.3303/17 (in mph) with complete flexible drive DG. 1110/22 of length 5ft 7 1/2 inches. Drive gearbox part no. BG. 5330/257
In 1959 the speedo fitted was S.467/203/N
Hope this helps
Thank you all for the valuable - but disappointing - information.
Both the instruments I have then require a 15/12 gearbox, but the bike has a 2/1 box.
So they will be seriously overeading.
As the bike is not been prepared for strict originality, I was hoping I could use one or the other of them.
I need to search further but not much chance of finding the correct instrument here in South Africa.
Fine that you might like to use either speedo if possible, but of course if you can't get the right one, then changing the speedo box might be a cheaper option. The 15/12 being the commando box and relatively easy to find.