Author Topic: Speedo  (Read 1366 times)

Offline terryk

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Speedo
« on: 22.01. 2009 12:01 »
Hi does anyone have a list of numbers etc to tell what smiths speedos go on different british bikes. What are the numbers for A10 and A7. thanks
1950-53 A10 rigid/plungers, 1958-61 A10 super rockets, 1947-50 A7 longstrokes, 1949 Star twin,
1951-54 A7 plungers, 1940s M21, WDM20s,
1948-50s B33s rigid/plunger/swingarm, 1948-50s b31s rigid/plunger/swingarm

Offline NickSR

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Re: Speedo
« Reply #1 on: 22.01. 2009 21:41 »
Hi
Speedo No: for my 1962 Super Rocket (Cowel Headlamp) SC 3305/04 this has a  bottom trip.

Regards Nick

Nottingham
England
1962 Super Rocket
1955 BSA C11G
1998 BMW R850R

Offline olev

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Re: Speedo
« Reply #2 on: 23.01. 2009 08:41 »
Terry,
Can't vouch for its accuracy. I have a better list somewhere which I'll post if/when it surfaces.

http://www.geocities.com/motorcity/downs/9472/smithsgauges.html

cheers

Offline terryk

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Re: Speedo
« Reply #3 on: 25.01. 2009 10:08 »
Thanks Nick and Olev thats great. cheers
1950-53 A10 rigid/plungers, 1958-61 A10 super rockets, 1947-50 A7 longstrokes, 1949 Star twin,
1951-54 A7 plungers, 1940s M21, WDM20s,
1948-50s B33s rigid/plunger/swingarm, 1948-50s b31s rigid/plunger/swingarm

Online trevinoz

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Re: Speedo
« Reply #4 on: 28.01. 2009 22:24 »
Terry, it's probably more important to get the correct ratio speedo than by number. After all these years anything could be inside the works.
Some reco units have no numbers on them.
The standard Flash and Rocket ones I have are 1450 revs per mile. If you change gearbox or rear sprocket size, you have to recalculate the ratio.
  Trev.

Online RichardL

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Re: Speedo
« Reply #5 on: 29.01. 2009 04:20 »
Terry,

Back awhile, one of our members, a chap called "manosound" posted some explanation and calculations regarding the revs per mile value. Those revs are the actual turns of the speedometer cable per minute for 60 mph or the total turns for one mile on the odometer, or so he says. If this is a going question for you, you might find the post interesting reading. Keep in mind that the ratio of wheel turns to cable turns relates to manosound's bike and may be different on yours. Here is the link:

http://www.a7a10.net/forum/index.php?topic=701.msg4399#msg4399

Richard L.
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