The correct speedo cable makes a difference

When I bought my 1974 Commando from the original owner about a year ago, the clock showed about 32,200 miles. The speedo had been rebuild once, maybe 15,000 miles ago. It was running on a Smiths cable and the housing was cracked and broken in places, probably the original cable. The needle danced wildly and the "your speed" signs around town proved it to be about 15 mph fast, 50ish was actually 35.
It's getting harder to find a business that rebuilds Smiths gauges here in the USA and while I have done business with Vintage British Cables in Canada, I figured that after his fee and shipping, buying a rebuilt from a vendor in the USA was not much more expensive and satisfied my instant gratification. So I bought a new (rebuilt) speedo, and speedo drive, and I had put on a new cable already that only had a couple thousand miles on it. New drive and speedo but no joy! The needle still danced around (up to about 50mph), then got smooth beyond that. Remembering a conversation with VBC, I recalled that he said the length of inner cable going into the instrument can cause problems. So, I patched up the outer cable of the old Smiths cable, lubed up the inner cable and now my rebuilt speedo is rock steady at all speeds!
The "your speed" signs around town show it to be reading about 5mph fast, but I can live with that! I was running a Shibako (Japan) replacement cable that was sold as correct for a 74 Norton.
It is a real shame that VBC in Canada is no longer able to sell reproduction cables that were exact spec and used Smiths ferrules and crimping machines. I still might send off my original speed to VBC, it would be fun to have the original mileage on the bike showing on the odometer. Anyway, I thought I would share this to help the next guy battling speedometer woes.

A bit of black rubber sealant on the cracks and breaks of the outer cable...


Original paint and complete engine and chassis rebuild last winter, it just keeps running better and better....

Nice job!

I normally use silicone self amalgamating tape, but that seems to work well.

I wonder if you could utilize one of these to hold the cable away from the bottom yoke? (Triple tree)




Roadsters look fantastic in blue don't they!

And red, and yellow, and black, and silver, and purple, and, and, and..............

I also wonder if the Shibago inner cable could be ground down to match the length of the original Smiths?

Jonez69 said:

I also wonder if the Shibago inner cable could be ground down to match the length of the original Smiths?

Click to expand...

Yes, I'm sure it could. You can pull the inner cable out from the top, and compare the lengths. The Shibago is probably too long.

Jonez69 said:

When I bought my 1974 Commando from the original owner about a year ago, the clock showed about 32,200 miles. The speedo had been rebuild once, maybe 15,000 miles ago. It was running on a Smiths cable and the housing was cracked and broken in places, probably the original cable. The needle danced wildly and the "your speed" signs around town proved it to be about 15 mph fast, 50ish was actually 35.
It's getting harder to find a business that rebuilds Smiths gauges here in the USA and while I have done business with Vintage British Cables in Canada, I figured that after his fee and shipping, buying a rebuilt from a vendor in the USA was not much more expensive and satisfied my instant gratification. So I bought a new (rebuilt) speedo, and speedo drive, and I had put on a new cable already that only had a couple thousand miles on it. New drive and speedo but no joy! The needle still danced around (up to about 50mph), then got smooth beyond that. Remembering a conversation with VBC, I recalled that he said the length of inner cable going into the instrument can cause problems. So, I patched up the outer cable of the old Smiths cable, lubed up the inner cable and now my rebuilt speedo is rock steady at all speeds!
The "your speed" signs around town show it to be reading about 5mph fast, but I can live with that! I was running a Shibako (Japan) replacement cable that was sold as correct for a 74 Norton.
It is a real shame that VBC in Canada is no longer able to sell reproduction cables that were exact spec and used Smiths ferrules and crimping machines. I still might send off my original speed to VBC, it would be fun to have the original mileage on the bike showing on the odometer. Anyway, I thought I would share this to help the next guy battling speedometer woes.
View attachment 131267
A bit of black rubber sealant on the cracks and breaks of the outer cable...
View attachment 131268
View attachment 131269
Original paint and complete engine and chassis rebuild last winter, it just keeps running better and better....

Click to expand...

You have phone booths in Iowa?