Speedo Healer

I have lowered my gearing on my Speed Triple, down 1 tooth on the front sprocket and up one on the rear. This has the effect of showing 90mph on the speedo when I know I am doing 70mph according to the sat nav.
To correct this, I found a device called Speedo Healer (~£90) from Bikers Discount Store (UK) that you plug in between the speedo sensor and the bikes CPU, you can then adjust the readout to show the correct calibrated speed, it also reduces the miles being recorded.
My issue is the legality of such a device, as it is clearly open to abuse to reduce the mileage being recorded! Hell, plug this in and it could be set to record 1/10th the actual mileage being done!

Anyone else use such a device?
http://www.bikersdiscountstore.co.uk/speedo-healer-pl-19.php

 

When the bike was in for service at the Triumph dealership on Friday I specifically asked about having the speedometer etc corrected for the gearing, and they said it was not possible to do this "it is a completely untrue that the speedometer can be adjusted"
So I did some research and found the Speedo Healer and placed my order.

Bugger!

 

Order cancelled for the Speedo healer and order placed for a cable, many thanks for the info Thebiglad, you just saved me almost a £ton!

 

I now have the Lonelec cable thanks to next day delivery
I have installed the drivers to the Laptop
I have even opened up the same ECU file that is currently on my bike (details on the service record)
I have read the full instructions, several times

So tomorrow afternoon, I will try connecting to the bike and changing the speedo by -15%

Looking at the values of the map, they do seem to be a bit haywire, but I guess as they are direct from Triumph they know what they are doing, it just looks, well, messy. Particularly on the graph mode!
I certainly can't do better so not touching them.

 

Result!
Connected the laptop to the ECU and reduced the speedo by 15%, it is now slightly over corrected but very happy.
Thank you TheBigLad for pointing me in the TuneECU direction.
Plus, thanks to jon for your feedback too.

Took all of 20 min to plug in, download the current Map, change the speedo by -15% and then upload back to the ECU.

Now to get further understanding of what TuneECU can do...

 

The best currency of all - Beer tokens!