smith chronometric vs magneto tacho speedo

At a guess I would say mid 60's, our 67 has magnetics.

Ibelieve 1964 was the last with chronometrics and 1965 the first with magnetic (at least for the 650SS).

Chronometric up to and including 1963; magnetic from 1964-on. Magnetic in 1960? No.....

Just to add to the confusion my 1966 650SS has a chronometric speedo and magnetic rev counter, though the latter could have been a later addition!

My 650SS/1966 had magnetics. I've replaced them with chronometrics.

Fritz

I think the change to magnetic clocks came with the fitting of the paired clocks on the mounting plate with the light switch in the middle (1965?). The chronometricspeedos were recessed into the headlight and the tacho (an optional extra)attached to the fork leg.

I have chronometrics on my '64 650ss but mounted on a pair of the tacho type brackets on the fork legs as that(in my opinion)looks far better than the original fitment.

Cheers

Graham

In 1963 Smiths listed the Chronometric Speedo SC3303/17 for the 88 & 99, SC3303/46 for the SS, Manxman & Atlas, and Rev-Counter RC1309/00 for all the big Norton twins.

In 1964 they listed Magnetic Speedo SSM3002/00 and Rev-Counter RSM3003/00 for the same application.

There may have been a bit of using up existing stocks during that changeover, one might imagine?

My 1964 650SS has Magnetics.

Even after 1964 some fits had chronometric instruments - notably for Police and Military use. When AMC adopted the "Bonneville" type headlamp for the 650SS to match the Atlas the instruments generally became magnetic. Cheers, Howard

Just to add to the mix / confusion I have copies of some ofthe original UK brochures:

1963 - pictures chronometric clocks, speedo recessed into headlight, tacho listed as optional extra mounted on fork leg. Atlas not listed but 'standard' 650 is - who has one of those?

1964 - no clear picture of clock face but recessed into headlight and tacho listed as optional extra for 88ss / 850ss. Atlas not listed

1965 - brochure / sheet shows picture of 88ss / 650ss with recessed clocks but no mention as optional extra. Atlas pictured with twin magnetic shaped clocks.

All above are UK spec and with the addendum that the brochures were not always accurate. US specs were different probably getting twinned clocks earlierand more chrome than the UK market.

I think you can go with whatever you can get or like the look of as the only people who will question it are the Nortonistas â?â?â?â?â?.. and even we disagree

Smiths also made a speedo that was a cross between a Chronometric and a magnetic clock. The 1963 Norton Atlas Scramblers, and the 1962,1963 Matchless G15/45 750 twins used this type of speedo. It is now a very rare type of speedo.

Previously Tomas Tesar wrote:

I have 1964 and have magnetic and i don't know is it right.i want to buy Tachometer too and i need know what is right for my bike.

Thanks

Tomas. What number is on the face of your Magnetic speedo? If it is SSM 3002/00 (miles) or SSM 3002/01 (kilometres) then it is most certainly correct. That is what is listed for 1964. If so, the magnetic Tachometer you need is RSM 3003/00.

To be clear, in 1963 all major UK motorcycle manufacturers using 3" instruments were fitting Chronometrics. In 1964 none of them were; they were all listing Magnetics. There is the odd exception. For example Velocette swapped part way through the year, listing both; they probably had a stock of Chronometrics to use up.

It would appear that, in the face of the manufacturers demand for cheaper instruments, by 1964 Smiths had fazed out the manufacture of the Chronometric in favour of the cheaper to produce Magnetic.

Previously ian_cordes wrote:

Previously Tomas Tesar wrote:

I have 1964 and have magnetic and i don't know is it right.i want to buy Tachometer too and i need know what is right for my bike.

Thanks

Tomas. What number is on the face of your Magnetic speedo? If it is SSM 3002/00 (miles) or SSM 3002/01 (kilometres) then it is most certainly correct. That is what is listed for 1964. If so, the magnetic Tachometer you need is RSM 3003/00.

To be clear, in 1963 all major UK motorcycle manufacturers using 3" instruments were fitting Chronometrics. In 1964 none of them were; they were all listing Magnetics. There is the odd exception. For example Velocette swapped part way through the year, listing both; they probably had a stock of Chronometrics to use up.

It would appear that, in the face of the manufacturers demand for cheaper instruments, by 1964 Smiths had fazed out the manufacture of the Chronometric in favour of the cheaper to produce Magnetic.

Hello for the 650 range the 3303/00 speedo and Rc1302/00 rev-counter were reliable increments, the 650 Manxman came before the 650ss in fact nearly a good 9 months before, and then April 20th 1962 the Norton Atlas 750s And some of youneed to realize we had a 650 Manxman before the 88/99 ss models which were introduced in April1961 which was five months after the 650 Manxmanwas exported, is because of the very valuable export market these fine motorcycles have been overlooked by the Uk motorcycle circles, and the motorcyclingmedia and today we turned full circle with the new 650 as an export machine , but to me the name of Atlas is the wrong name for this bike and better name would be Norton 650 predator but what do the member think yours anna j

Tomas. The SSM 5001/03 was fitted to 1964 BSA 500 & 650 twins. The 'B' suffix apparently denotes the trip version. However, it may be a US version. So, it is not likely to be original!

I don't know, Tomas, but others might. I was just saying the speedo appears to be off a 1964 BSA, possibly an export one.

Ian

It certainly looks to be the correct one, Tomas. A good find at the right time!