Speedo Question...

[pdw709]

I've finally got my CBR powered Striker on the road and through its MOT (still trying to remove the grin from my face). Next thing is I want to know how fast i'm going! - seems strange that a working speedo is not an MOT requirement!

Anyway, my speedo is an aftermarket one which has been grafted in to the bike cluster. Given that the age of my CBR engine did not have an electonic speedo when built, would the only way for the new speedo to work properly involve some kind of sensor attached to the wheels to monitor the rpm and therefore speed? Or else would the speedo somehow connect to the engine?

The reason I ask, is that I've given the wheels a quick visual once over and I can find no sensors.

Cheers

Phil

[Fer]

Have you considered a GPS unit? I am thinking of this as the solution to my speedo worries.

[docevi1]

Westfields use a small electronic sensor on the rear drive shafts - it sits just above the diff and counts the rotational speed of the shaft (using magnets & the nuts). Could yours be similar?

[pdw709]

said:

Have you considered a GPS unit? I am thinking of this as the solution to my speedo worries.

Not yet, I was hoping to get my existing one working. But if that proves impossible then a GPS unit would be a potential option.

Phil

[pdw709]

docevi1 said:

Westfields use a small electronic sensor on the rear drive shafts - it sits just above the diff and counts the rotational speed of the shaft (using magnets & the nuts). Could yours be similar?

Thanks, I'll check it out this evening.

Phil

[watsop]

Mines a ETB speedo (www.etbinstruments.com/)which uses a disc (with holes) on the propshaft plus a sensor. It seems to work pretty well but can be a bit inaccurate and bouncy at low speeds (whos going slow anyway) and can be calibrated on the speedo buttons. I was told that you can have problems with the other type as the magnets can tend to fall off, I don't know if anyone else can confirm/deny this. The one I have still needs the sensor range set up, as I found out at my SVA, otherwise it may misread.

[flossythepig]

Fer said:

Have you considered a GPS unit? I am thinking of this as the solution to my speedo worries.

How accurate are GPS units?

What happens if Bush decides to re-instate Selective Availabilty for security reasons (accuracy to 100m)?

Hugh

[pdw709]

docevi1 said:

Westfields use a small electronic sensor on the rear drive shafts - it sits just above the diff and counts the rotational speed of the shaft (using magnets & the nuts). Could yours be similar?

I had the car up on ramps over the weekend and had a good look at the underside. I could'nt find any wires/sensors anywhere near the transmission/axels/wheels, so I can't figure out how the speedo is mean't to work - assuming that it ever did!

Could the speedo be getting its information from engine some how?

I might have to try and contact the original builder for some clues. I'd rather try that option first rather then ripping out the speedo and retrofitting a new one

Phil