Speedo recalibrating

**Laava** · 30th April 2011, 17:47

Just finished road testing a speedo re-calibration device that I fitted. It is a SpeedoDRD from 12o'clock labs in the US. http://www.12oclocklabs.com/ $112 to my door
Basically it plugs in directly to the existing speedo sensing gubbins from the front sprocket. Apart from the tight fit of the wiring, fairly normal on most vehicles, it is plug and play. Once fitted it needs to be calibrated to suit the bike. This is dead easy. I changed the sprockets recently on my bike and went up 2 teeth on the rear and down one on the front. What this meant was that my already optimistic speedo was now screaming "yee-haa" at every oportunity! However the reality was that on the Northern motorway at a reading of 140kph, cars were going past me.

So I borrowed a sat nav and found out that at 100kph, my speedo said 120. There is a very usefull differential calculator on the 12o'clock website and using the -16.9% correction factor that it gave me I did the very easy programming to bring the whole plot up to speed. Or down to speed as the case may be! After a quick test ride today I can confirm that when my speedo was on 100kph, the sat nav was no more than 1kph in any direction. I should note that there will be small real-world factors to take into account, mostly tire wear which will affect it's accuracy but more likely when you change tires esp sizes. But probably small peanuts.
I have incl the DRD programming vid from Y/T as it was interesting to see how tiny the thing is and what is involved in setting up.

**slofox** · 30th April 2011, 18:17

Re tyre wear and speedo reading:

I have a speedohealer fitted to my bike - also calibrated from a GPS. I fitted it just as I bought new tyres. The GPS and the speedo were exactly the same after calibration.

Cut to a couple of weeks ago when the tyres were down to the belts on the back wheel. The speedo was reading 101km/hr when the GPS said 100km/hr. So it's a 1% variation only. That's on 17 inch BT016's fitted to the gixxer.