The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: sprint on 19.03. 2012 16:39

Title: Correct Smith Chronometric rev counter for Super Rocket
Post by: sprint on 19.03. 2012 16:39

Looking a 1960 SR with twin clocks. The rev counter is driven from the oil pump.

Normally fitted is a RC 1303/03 but the one I'm looking at has a RC 95 fitted.

Can anybody advise if a RC 95 and 1303/03 are interchangeable as I cant find any spec or details on a RC 95?

Title: Re: Correct Smith Chronometric rev counter for Super Rocket
Post by: wilko on 19.03. 2012 18:54

http://www.flickr.com/photos/9383961@N05/3025208238/in/set-72157608955201989/

Title: Re: Correct Smith Chronometric rev counter for Super Rocket
Post by: sprint on 19.03. 2012 19:49

Quote from: wilko on 19.03. 2012 18:54

http://www.flickr.com/photos/9383961@N05/3025208238/in/set-72157608955201989/

Thanks for the very useful link Wilko.

However, it does not help with the question as to whether the RC 95 is a correct rev counter for an oil pump driven Super Rocket as it does not list it?

Title: Re: Correct Smith Chronometric rev counter for Super Rocket
Post by: wilko on 20.03. 2012 03:14

Is it reverse drive or normal? Stick an old piece of cable in it and spin it. Looks like it's for a Matchy or AJS twin. http://www.flickr.com/photos/9383961@N05/2981803167/in/set-72157608455625820

Title: Re: Correct Smith Chronometric rev counter for Super Rocket
Post by: Brian on 20.03. 2012 03:41

This might not be much more help but....

BSA's use a RC83 when its driven by the magneto pinion, unfortunately I cant find a listing for the oil pump driven ones. The RC1303/03 is a 3:1 ratio anti clockwise.

The RC95 will fit most Velocettes, Nortons and AMC twins (AJS/Matchless)

Title: Re: Correct Smith Chronometric rev counter for Super Rocket
Post by: wilko on 20.03. 2012 22:01

If you go down this list to Smiths there are different years for the instruments. I was too lazy to go through them all!  http://www.flickr.com/photos/9383961@N05/collections/72157606126399856/

Title: Re: Correct Smith Chronometric rev counter for Super Rocket
Post by: BVSR on 28.03. 2012 20:39

Sprint,
The RC95 is 4-1 clockwise, so they are not interchangeable. The 1303/03 is the only 3-1 anticlockwise that Smiths made so You have to find one or a specialist can convert some other clock to 3-1 acw to You.
Markku