Speedometer Cable Routing (2010)

swooshdave · Aug 13, 2010

So I think I have the cable routing about correct. I welcome any comments.

Inside the fork ear.

Draped down the front.

Between the engine and frame.

Tied to the frame under the gearbox.

And back to the speed drive.

Yes? No?

Hobot · Aug 13, 2010

Same path factory and the rest of us settle on.
Where did you find an armored version?

swooshdave · Aug 13, 2010

hobot said:
Same path factory and the rest of us settle on.
Where did you find an armored version?

Andover Norton via Old Britts.

norbsa48503 · Aug 13, 2010

Dave, I find it to be better if you turn the speedo drive anti clockwise so that the cable is closer to the swing arm. Than tie it to the swing arm and untie it under the gear box. Each time the swing arm moves you don't want the cable bouncing at a different speed. The cable will than do it’s twisting bending - near the swing arm pivot.
Now on some bikes it is hard to get a zip tie to do this job on the swing arm without sliding back and forth so I use some Velcro as padding along with the zip tie to keep it stable. Just leave a little gap for the tie use a wide one too.

Hobot · Aug 13, 2010

Spilled the beans on what looks right vs works right. Its all about the bikes,
so mention the cable is under less strain with the drive angled downward.
There's a trick to getting the clock end of cable seated right, not too much nor too little. I never had trouble at clock end so don't remember the details, but a search here should if no one reviews it here.

stockie1 · Aug 14, 2010

Dave, looks like real quality, it's nice when they are all fresh and clean. The cable looks top quality, but always worth checking how much cable is protruding out the cable sheath. Should be no more than 7/16" I have had inners cables which are too long and after time they destroy the speedo head.

Cheers Richard

L.A.B. · Aug 14, 2010

hobot said:
Same path factory and the rest of us settle on.
Where did you find an armored version?

Although many brochure photos show the speedo and tacho cables neatly routed behind the lower yoke/tree, every period photo from road tests etc. I can find shows the cables passing down in front of the lower yoke-which would be how I would normally route them.

Example:
http://www.classicbike.biz/Norton/Mags/ ... -World.pdf

Myford · Aug 14, 2010

I fitted a new cable (Norvil) don't recall now whether it was AN or pattern, & the speedo got slower & slower. replaced the drive unit & the same thing was happening. After a lot of head scratching I pulled out the inner cable & offered up the square end into the drive unit & found that said square end was well under size (or the square hole in the drive unit was over size). I shimmed it with small strips of shim steel & it was fine. Dave, you might want to check yours.
Whilst I had the inner cable out I noticed it was bone dry, so I gave it a liberal dose of oil. I should have remembered that the rotation of the cable carries the excess oil up to the the speedo, so very soon I had a 150 mph plus Commando!
A good squirt of solvent up the light hole sorted it, but I did have a good chuckle to myself.
Terry

nickguzzi · Apr 7, 2014

At the time tachos became law here in UK, I was roped into fitting a few. This was official VDO instructions at the time.
Any sort of drive cable should be lightly lubricated but always leaving the last few inches clear, otherwise the lube will ruin the head. This may be of greater import on a truck tacho as legalities are involved. (I think they are all electronic now).
There is a proper grease for cables. Its like a very light moly grease, it doesn't seem to thicken and get claggy in use. There's no markings on the drum I have, except its black.

L.A.B. · Apr 7, 2014

nickguzzi said:
At the time tachos became law here in UK,

To avoid any possible confusion, "Tachos" in this instance refers to tachographs not tachometers as I'm not sure anyone outside the EU would necessarily know what a tachograph is.

http://en.wikipedia.org/wiki/Tachograph

drones76 · Apr 8, 2014

I know you are really enamored with yellow but can I send you a nice black tie wrap? :twisted:

pete.v · Apr 8, 2014

I do not know what the factory would do and I am sure there was more than one way depending who was on the line that day.

Simply choose the path of least resistance that offers the smoothest and most accurate functionality and secure placement.
I would bet the judges at the concourse will see this as proper........or not.

swooshdave · Apr 8, 2014

drones76 said:
I know you are really enamored with yellow but can I send you a nice black tie wrap? :twisted:

That's actually fluorescent yellow! My daughter gave me a pack of neon colored zip ties for Christmas and I use them for temporarily holding stuff and then use the black zip ties for final placement. :mrgreen:

drones76 · Apr 8, 2014

swooshdave said:
drones76 said:

I know you are really enamored with yellow but can I send you a nice black tie wrap? :twisted:

Click to expand...

That's actually fluorescent yellow! My daughter gave me a pack of neon colored zip ties for Christmas and I use them for temporarily holding stuff and then use the black zip ties for final placement. :mrgreen:

Oh from the daughter. All good then. I had a hello kitty sticker on my old CB for a couple years when my niece said it would look nice there.

contours · Aug 23, 2019

norbsa48503 said:
I find it to be better if you turn the speedo drive anti clockwise so that the cable is closer to the swing arm. Than tie it to the swing arm and untie it under the gear box. Each time the swing arm moves you don't want the cable bouncing at a different speed. The cable will than do it’s twisting bending - near the swing arm pivot.

Sorry for dredging up an old post, but I think this particular suggestion could help my situation. Currently the speedo cable on my Mk3 is dangling below the swing arm and appears too close to the chain, in my opinion. So it does seem reasonable to rotate it the way norbsa48503 suggests and secure it to the swing arm. Is this an uncommon arrangement?

L.A.B. · Aug 23, 2019

contours said:
So it does seem reasonable to rotate it the way norbsa48503 suggests and secure it to the swing arm. Is this an uncommon arrangement?

I would have said that was the normal thing to do to keep the cable run as straight as possible and avoid unnecessary bends.

contours · Aug 23, 2019

Thank you L.A.B. I'm going to do this because the way it is currently installed makes me uneasy.

L.A.B. · Aug 23, 2019

joe czech · Aug 24, 2019

i know it's a 9 year old thread, but let me add in my 2-cents. here's a pic of what's supposed to be an original 74-850 that was discovered in the original shipping crate. i'm sure most of you have seen this, but just re-posting for the details. if you click on the picture, you can enlarge and see all kinds of engine and frame details. not saying this is 100% accurate, but it is worth a look. https://www.bonhams.com/auctions/19679/lot/275/?category=list&length=10&page=26 - click on the pic, and enlarge. you will see the speedo/tach cables route in front of the lower fork yoke. also, note the tank/side covers paint. i'm thinking there's another open thread with questions on the stripping. note, the site says "1975" where it's clearly a 74 Mk2. just for general information, my 74 is also titled as a 75 -

contours · Aug 24, 2019

L.A.B. said:

This photo shows it pinned to the swing arm without rotating the drive. Easier to do. A photo of my speedo drive would show the cable hanging down by the chain.

Speedometer Cable Routing (2010)

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