Misc: Everything Else Comet Speedo Won't Work Puzzle

[Chris.R]

Hi I have a puzzle the speedo head fitted to my C Comet is a standard Smith unit the needle is not working won't move in spite of being serviced more recently. What happens is the unit stopped working a while back on a ride, I had it proffesionally serviced by Philip Woods so should function correctly. I am getting the same problem the odometer registers correctly but needle does not register speed and sits stubbonly on zero.

To look at the other end can the speedo head be removed without taking the front wheel out to inspect the 3/32 split pin is not broken?

The cable has been renewed.

Any ideas folks.

Chris

 

[vibrac]

I lost the odometer in Spain I had it repaired and now it works however now the speedometer has stopped working one thing is certain if either works the cable is working and the problem is in the speedometer mechanism. Its gone back to the menders

 

[bmetcalf]

Yes, the pinion is just smaller than the hole in the brake plate and the assembly can be removed without taking the wheel off.

 

[Chris.R]

Thanks for the comments as they say every little helps looks like I will have to take both ends off to check further the split pin and to send the head back again.

 

[Chris Launders]

I would point out if the needle doesn't move at all but the odometer works it's a failure in the mechanism.

You have to realise that the speedo and odometer are only connected just as the shaft enters the head, after that they are entirely separate.

 

[The VOC Spares Company Limited]

Check to direction of rotation of your gearbox on the front wheel. The odometer works in both directions, but not the speedometer. Try an electric drill with reverse in both directions.

 

[ericg]

A Smiths magnetic speedo cable fitted to chrono would induce the exact symptoms.

 

[bmetcalf]

How are they different?

 

[clevtrev]

First thing is to find out where the problem is, so remove cable completely, rotate wheel and look to see if there`s movement in the gearbox. If no, you know where to start, if yes, then proceed. Replace cable at the wheel gearbox, rotate wheel again and see if cable is turning at the top end, that`s OK, now you know the problem is in the speedo itself. If not the cable is not driving properly, tang broken / cable broken.

 

[Chris Launders]

A Smiths magnetic speedo cable fitted to chrono would induce the exact symptoms.

How, it is either driving the speedo or it's not.