Forum

[PeteF]

I fitted a Chinese knock-off of a Smith's Chronometric (not that it's chronometric)
It's only been on a few hundred miles but so far it's steady and accurate to within 1-2 mph.
£12 off Fleabay.

[ric]

Don't forget printed labels should be placed under the glass, or removed prior to an MOT.

[PeteF]

As I understand it, a speedo is not an MOTable item. Legally necessary however.

[wilf]

Does anyone know if the later EFI type speedo is any more accurate than the older type as fitted to the iron barrels?

[Thack]

I checked the one on my 2014 UCE using several runs and GPS. It was 5mph fast at 30mph, and 3mph fast at 70mph, with the error decreasing in a straight line between those speeds.



I calibrated mine by the simple measure of moving the needle back by 3mph. Thus it is now 2mph fast at 30mph, and spot on at 70mph.

[wilf]

Hi Thack, do you mean you removed the glass, moved the needle to 30, held the spindle somehow and took off the needle, replacing it at the 25 mark?

[Thack]

Hi Wilf,



That's right, although I did it by taking the glass off and taking the mechanism out of the case entirely - much easier to work on.



I wasn't able to jam the mechanism with the needle at 30, but it didn't matter because I found I could jam it at about 45 with a piece of metal rod pushed through the mechanism. At 45mph the error was still about +5mph, so that was OK. I took a mental note of the exact speed the needle was showing.

The needle was on extremely tight, so I bent a couple of old screwdrivers so they looked like tiny crowbars and levered the hand off the spindle. It is essential to lever AGAINST THE TWO SCREWS near the middle of the dial, not onto the dial itself or you will ruin it.



I then replaced the hand exactly 3mph further back and gently tapped it down. Remember, I chose to leave the speedo 2mph fast at 30mph, so it would be spot on at 70mph.



There is one last job. Originally the needle pointed at 0 when the bike was at rest. It now points at -3mph, obviously. If you look in the mechanism there is a long metal strip which acts as a back stop for the shaft connected to the needle. Just bend this with a pair of pliers until the needle is pointing at 0 again.



Clearly I've no idea how accurate the speedo is below 30mph, but I don't care about that. I rechecked it with GPS and can confirm that it is now just what I expected: 2mph fast at 30, spot-on at 70, and a declining error between 30 and 70. Most satisfactory.

[Thack]

Chris writes: "I've seen quite a few tilting the speedo towards the rider. It needs to be AWAY from."



If it tilts TOWARDS the rider, the speedo case fouls the back of the headlight bulb. Is that what you were referring to?