Author Topic: Speedo Cable Length and Route  (Read 3241 times)

Online RichardL

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Speedo Cable Length and Route
« on: 29.10. 2008 15:15 »
Gents,

I've purchased an original chronometric speedometer on Ebay. It will no doubt need cleaning up and, perhaps, work. Fortunately, my father-in-law is a clock enthusiast and has the discipline and experience, if not chronometric-specific knowledge, to help with the internals of the device. Pictures and stories of the speedometer cleanup will, no doubt, be forthcoming.

The questions I need to ask here are: 1) For a speedo-only installation, what is the preferred mounting position for the device when the headlight is of the ear-mounted non-nacelle type with the centered ammeter and light switch? I believe I will will want it off-center to one side in order to view/ reach both of the aforesaid. 2) On a '55 swingarm, what is the recommended cable length? 3) What is the correct path for the cable? 4) What would be a good (or the best) place to buy a mounting bracket.

I suppose I could spend a great deal of time perusing photos and searching the internet for information on this, but if anyone here has specific easy-to-access information, that would be much appreciated.

Richard
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline LJ.

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Re: Speedo Cable Length and Route
« Reply #1 on: 29.10. 2008 22:09 »
Well... On my recently required Star Twin the speedo is smack in the middle and I have been quite comfy with its position I can still see the amp meter and light switch is still easy to get to. I'll have to have another look at the way it is fixed if you require further advice. Length of cable? I dont think it would be much different from the early A7 to mid 50s A10 but as far as fixing and routing goes... I would only have one nylon cable tie about mid way.

Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Online groily

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Re: Speedo Cable Length and Route
« Reply #2 on: 30.10. 2008 10:42 »
Yup, mine's in the same place as LJ's, smack in the middle. I don't have the correct headlamp for any A10 of any year I'm sure, but it contains just a 2inch Miller-style ammeter which is readable easily. The switches are on the handlebars - the less said the better as far as 'how it ought to be'. But they work. The (standard s/arm BSA part?) speedo cable would be long enough to have the speedo off-centre either way if necessary, and I have one tie on the rh downtube down towards the front engine plate. The cable runs as directly as possible from the gearbox along the rh side of the bike under the engine and then sweeps upwards in the gentlest line achievable to avoid tension on either lock. That of course in no way answers the Q 'How Should It Be?' but I can't imagine it should be much different!
Bill

Online RichardL

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Re: Speedo Cable Length and Route
« Reply #3 on: 30.10. 2008 12:06 »
Thanks guys. The idea of being on center is reinforced, though, I like seeing the light switch. It is part of the "really old motorcycle" feel of the thing, as I believe it is the original switch. OK, it's just there to turn on the lights. There is a bigger problem described below.

 The contr-ah-versy (British English?), goes to something I've failed to mention. Harkening back to '73 (when I bought it), '79 (when I wrecked it), then '03 when I started to rebuild it, I had no idea what constituted original for all parts. After having the headlight ears rechromed and buying an A10 top tree, I went to put the forks together to discover that the ears were an inch too short. What I didn't know was that the bike, as bought in '73, had an A50 top tree and ears. Not wanting to throw out the expensive chrome job and pay for new ears, I bought an A50 tree, as shown in the photo. Ipso facto, no instrument mounting holes and the lock is on center. So, I think I might need a mount that goes under one of the top fork nuts. 

I have included photos of the tree and the custom lock plate I made to compenstate for the on center lock. Every speck of dust looks like a major flaw in these photos. By the way, is there any way the dropped-end tree was used on A10s. I think it must have been a later developement.

Finally, if anyone has a single off-center speedo, it would be great to see a photo.

Richard
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Offline fido

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Re: Speedo Cable Length and Route
« Reply #4 on: 30.10. 2008 19:18 »
The  BSA bracket will be the same as for a Goldie so you could try the Goldie specialists. The holes for it are drilled and tapped in the top yoke so you could choose where to mount it. If you want to mount the speedo to a fork top nut it is easy to make a bracket from sheet aluminium. I did this on my B31 when using Honda forks.

Offline trevinoz

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Re: Speedo Cable Length and Route
« Reply #5 on: 30.10. 2008 20:59 »
Richard, why not use a Rocket Gold Star set-up? It consists of a triangular bracket mounted under one of the fork top nuts   [make sure you have the long ones] with a finger bracket bolted onto it. The RGS used a longer finger bracket than the standard one. Accessory Mart used to sell the finger brackets.
Hopefully your speedo case has the two studs on the bottom.
                                                                                      Trev.

Online RichardL

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Re: Speedo Cable Length and Route
« Reply #6 on: 30.10. 2008 21:10 »
Trev,

That sounds like the answer. I know about the finger but haven't seen the triangle. I'll check Accessory Mart for both. Thanks.

Richard
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.