Author Topic: Goldie tach drive on Road Rocket?  (Read 1067 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

Online 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.

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

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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

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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