Author Topic: Goldie tach drive on Road Rocket?  (Read 1785 times)

Offline roadrocket

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Goldie tach drive on Road Rocket?
« on: 13.12. 2015 21:32 »
Hello

I have learned that the right tacho for a Road Rocket is RC 83 (RC 1302/00) 2:1 Clockwise. Will a Goldie 1:1 drive be right for that? I take that the mag turns at half engine speed.

Otto in DK
Otto in Denmark

Offline chaterlea25

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Re: Goldie tach drive on Road Rocket?
« Reply #1 on: 13.12. 2015 22:17 »
HI Otto,
Both bikes run anticlock magnetos so the drive unit should be correct,
A fact about goldies is that they wear out the revcounter mechanism rapidly  *sad2*
This is because of the high cable speed,  = 1/2 engine speed

My plan is to use a 2:1 drive box and a suitable rev counter with a "correctly" marked dial (Shhhh!!!)

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline Klaus

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Re: Goldie tach drive on Road Rocket?
« Reply #2 on: 14.12. 2015 00:01 »
If you looking for 2:1 tach drive, l can offer you one. Only used one year in a racer.

cheers Klaus


If you think, everything is under control, you are not fast enought.

BSA DB34 Goldstar, BSA A10 Road Rocked, BSA A7 Shooting Star, BSA M33, BSA M24, Kawa W650

Offline roadrocket

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Re: Goldie tach drive on Road Rocket?
« Reply #3 on: 14.12. 2015 16:16 »
Thanks folks, can my information about the instrument be correct RC 83 (RC 1302/00) 2:1 clockwise be correct if the mag runs anticlockwise? The things is that I have an excellent place to buy both the instrument and the drive, but the drive is black, and I would so much prefer to get one of Phil Pearsons beautiful brass drives for Goldies. If the mag runs the same way on A 10s and Goldies, I would at least suspect they could use the same tachometer, given the gearing is the same. Klaus how odes your drive look?

Cheers, Otto
Otto in Denmark

Offline chaterlea25

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Re: Goldie tach drive on Road Rocket?
« Reply #4 on: 14.12. 2015 18:05 »
Hi Otto,
A link to the application chart, http://www.chronometrics.co.uk/Tachometers/tachometers.html

As the drive unit has gears the output is reverse to input  *conf2*

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline roadrocket

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Re: Goldie tach drive on Road Rocket?
« Reply #5 on: 14.12. 2015 19:07 »
I know you can get drives that either keep the direction of the mag (or other prime mover), or reverse it. My question is: for a clockwise instrument, do I need a drive that keep or reverse the rotation? I would think that if an instrument is designated clockwise, it should get a clockwise rotating cable. But now I must say I am totally confused.

Cheers, Otto
Otto in Denmark

Offline chaterlea25

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Re: Goldie tach drive on Road Rocket?
« Reply #6 on: 14.12. 2015 22:49 »
HI Otto,
The magneto "direction" is defined looking at it from the drive end
So looking at the inner end of the drive box it will rotate clockwise
(maybe I stand corrected on the direction change as it will depend on which way the worm gear is cut *????*
this is an extract of the fitment list I have on the pc

John.

Smiths Chronometeric 
Model Information


Model   Speedometer   Tachometer   Speedometer Gear Box   Tachometer Gear Box
           
BSA           
D1              -1958   S.630/L         
D1 Bantam 123cc   SC 1102/07      BG5331/247   
D3 150cc   S.630/L         
D5 175cc   SC 1102/L         
C10 250cc   S.630/L         
C11   S.433/1/L         
C12   S.433/1         
C15 Starfire Roadster 250cc   SC 5301/03      BG5331/247   
C15 Sunbeam 250cc   ↑      BG5330/847   
C15 Trials   SC 1102/14      ↑   
C15 Scrambler   SC 5301/03      ↑   
B31 -1957   S.608/9/L         
B31 1958-   SC 3305/04         
B32 Triail & Scrambler  -1957   S.525/3/L         
B32 Comp   S.608/11/L         
B33            -1957   ↑         
B33            1958-   SC 3305/04         
B32/34 Goldstar    1954-1956   S.546/3/L   RC.83     
B32/34 Goldstar    1957   S.608/11/L   ↑     
B32/34 Goldstar    1958-   SC 5301/23   RC 1302/00      BG 5331/247
B32/34 Goldstar Scrambler    SC 5301/07   ↑     
B32/34 Clubmans   SC 5301/23   ↑      BG 1508/04
M20           -1954   S.608/9/L         
M20            1955-   S.608/11/L         
M21           -1957   S.608/3/L         
M21            1958-   S.433/3/N         
M33    S.608/3/L         
A50   SC 5313/00         
A50 Star   SC 3313/00         
A65   SC 3313/02         
A7             -1957   S.608/19/L         
A7             1958-   SC 3305/04         
A10            -1957   S.608/11/L         
A10 Super Rocket   1958-1962   SC 5301/22   RC 1303/03     
A10 Super Rocket   1963-   SC 5301/06   RC 1303/00     
A10 Golden Flash   SC 3305/04         
A10 Spitfire Scrambler   SC 5301/24         
A10 Rocket Goldstar U.S.A.   SC 5301/23   RC 1303/03     
A10 Rocket Goldstar   SC 5031/03   RC 1303/00     
           

1961 Super Rocket
1963 RGS (ongoing)

Offline roadrocket

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Re: Goldie tach drive on Road Rocket?
« Reply #7 on: 15.12. 2015 17:47 »
I have done some more research, and found that the Goldie tach drive will be correct for a RC83 instrument as specified for a Road Rocket. This is because: the BSA p/n 65-9164 (Smiths 1508/05) is a 1:1 reversing drive, and since the mag rotates at half engine speed in anticlockwise direction, it will be correct for the RC83 which is a 2:1 clockwise instrument. A nice chap dealing with Velocettes had a lot of Smiths information on his blog. Google the Velobanjoagent. At least this is what I could squeeze out of the combined web resorces of an evenings worth of surfing.

Cheers, Otto
Otto in Denmark