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Motorcycle Discussions => British Bikes => Topic started by: Oggers on March 25, 2022, 04:54:06 PM

Title: Erratic chronometric
Post by: Oggers on March 25, 2022, 04:54:06 PM

Gents

Smith chronometric speedo on a 55 Velocette MSS has developed a fault. Basically it is reading very low - reads 10 mph when shoud be 40 or so. Mileometer works, cable looks OK, no sharp turns or kinks in the cable. Fine yesterday!

Clues appreciated.

Thanks as always

Mark

Title: Re: Erratic chronometric
Post by: R on March 25, 2022, 09:27:06 PM

Are you intending to diy, or take it to a specialist ?

Title: Re: Erratic chronometric
Post by: Oggers on March 28, 2022, 08:14:04 AM

A few drops of wd40 seems to have sorted it....I like simple solutions.

Title: Re: Erratic chronometric
Post by: Rex on March 28, 2022, 11:15:40 AM

From what I've experienced and read over the years, the grease used on assembly goes hard and stops the finely-tuned mechanism from incrementing and returning. Presumably the WD40 softens the hard grease enough to allow it to work as it should.
 Whatever solvent is used never ever get it on the drums or face as the numerals smudge and fade very easily.

Title: Re: Erratic chronometric
Post by: iansoady on March 28, 2022, 11:53:41 AM

Quote from: Rex on March 28, 2022, 11:15:40 AM

s the numerals smudge and fade very easily.

Yes, I can endorse this having ruined a trip drum many years ago.