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Title: Chronometric speedo and tach
Post by: MJM_58SR on 17 Dec, 2019, 05:10

Would anyone have the information for the correct speedo and tach for a 1958 Super Rocket please?
I have s525/3 speedo and 1309/00 which I don't think is right

Title: Re: Chronometric speedo and tach
Post by: Bess on 17 Dec, 2019, 10:30

Hi,
Hope this helps.

Best wishes...

Title: Re: Chronometric speedo and tach
Post by: JulianS on 17 Dec, 2019, 13:37

If your rev counter is driven from the mag pinion you need either RC83 or 1302/00 (later version) face numbers.

If driven from the oil pump then you need 1303/03 face number.

The ratios are different between the 2 different drives.

1309/00 is for a Norton, dont know if the right ratio for your bike.

Title: Re: Chronometric speedo and tach
Post by: MJM_58SR on 17 Dec, 2019, 14:36

Thanks for the replies
I'm new to this so posted a photo of the connection, is this connected to the mag pinion?
The 1309/00 looks to be 2:1 so i think its the same as the RC83.
I think i have also now found buried in literature that the s525/3 is a 1650 and i should have a 1440, does that make a huge difference in speed recorded?
I am intending to send them over to Nottingham to get them sorted in the new year, he did a great job on the C11G speedo and i didnt think too bad on price either
Thanks

Title: Re: Chronometric speedo and tach
Post by: JulianS on 17 Dec, 2019, 15:42

Yes that is driven from the mag.

Title: Re: Chronometric speedo and tach
Post by: MJM_58SR on 17 Dec, 2019, 15:57

Thanks Julian
i have been told by a restorer (not the one from Nottingham i hasten to add) that 546/3/L is the correct speedo at 1450 TPM (for 1958 super rocket)? That looks like its for a gold star referring to Bess's reply.

So with the replies I think i need to go for
RC83 Rev Counter
SC 5301/22 Speedo or should this be SC5301/06

BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: MJM_58SR on 17 Dec, 2019, 05:10