My BSA's Smiths Chronometric is more guessometer than speedometer.

Having read the article on overhauling the Smiths Chronometric speedo I found in the technical section of the website I have a couple of questions:

Instead of using petrol to clean all the parts could I safely clean the speedo in an ultrasonic cleaning tank with a mild detergent?
Is it really as straight forward as it seems. Are there any major pitfalls I'm likely to come across and then wish I hadn't started?

Thought it might keep me quiet over Christmas while I can't move due to Turkey overload!

Any advise appreciated.

Stuart

email (option): stu.gibbins@btinternet.com

Stuart. I rebuilt mine and so far it has lasted 1,500 miles. I would suggest doing it on a white rag that wont be disturbed, have a powerful magnifying glass on a stand, and illuminate the job well. Have tweezers and very fine screwdrivers (jewellers tools).
Read all the information before you take it apart and understand how it works. Make notes as you go. I cleaned my parts with a small soft paint brush dipped in white spirit. Lubrication for reassembly was sowing machine oil applied with a modellers brush.
It took me much longer than I expected it to, but it was a therapeutic and rewarding job.

email (option): Gasboy@btinternet.com

I think a common cause of speedo trouble is over oiling of the cable, which the revolving cable screws into the speedo head. Iv had this problem on magnetic speedos as well. So keep the top 6 inches of the cable dry

email (option): Gasboy@btinternet.com

Thanks for the advise Peter.

Stuart

email (option): stu.gibbins

I'd love to do mine myself, but I know I'd cock it up or lose something tiny out of it, so I've just had it overhauled by Russell at www.chronometrics.co.uk The trip wasn't working and it was basically very tired and grubby. He's cleaned it, replaced some broken/worn out internal bits, got the trip working and put me a replacement bezel on for £30 all in.

Bill
Its worth getting it done proffesionaly for that price. I suppose I was lucky in that it obvious what was wrong with mine(the spring fixing screw had dropped off), so no spares were needed.

email (option): Gasboy@btinternet.com

Here is a tip. Don't drop anything!!!. If you can find it it will be broken.I need a balance wheel. Droped it,broke it!!!. So if any one has some parts or a spare balance wheel ,send down my way ( New Zealand ).Good luck with your speedo .

email (option): wpgarage@xtra.co.nz

I have a few. What thickness?

I've decided to send my speedo to Russell at www.chronometrics.co.uk, as per Lincoln Bill's recommendation. Price for my refurb/service including any parts required will be £65, so Bill's £30 was a bargain!

Stuart

email (option): stu.gibbins@btinternet.com

I did drop mine off and pick it up in person, so I saved myself the cost of the postage. I would imagine yours is more involved that mine was? At least by getting Russell to do it, you get a 12 month warranty too.

Just a quick tip for your Smiths Chronometric overhaul. It may sound daft, but don't forget to repaint the inside of the case white if it needs it. I've just done mine and it's gone from a dull orange glow to a lovely bright white light. I can actually read the numbers in the dark!!!

I'm dropping it off with Russell tomorrow Bill. I don't have any speedo illumination on mine .

Stuart

email (option): stu.gibbins@btinternet.com

Ahh, good point Stuart. I'd forgotten that my Matchless is a bit of an oddity. It's one of a batch fitted with standard 'civilian' type speedometers with the trip counter and light. It always seemed odd to me and I've never been able to get a satisfactory answer as to why this batch were given these speedometers. The light was wired up when I got the bike, but during the war it would perhaps have been blanked off and not wired in? Forget my previous advice then, carry on!