13/47 sprocket change? What % was your speedo off?

Hi guys
Topic says it all
I got around 20% from the speedo app on my iPhone but don't know how accurate it is and I found it a little dangerous comparing 2 speedo's while trying to ride safely

I would like to know what percentage your speedo was out if you have 13/47 sprockets

I have D606's with around 85% tread left,

...so a % and back tyre info would both help

Go here: click me

Under "Products" Then under "SpeedoDRD" you'll find "Setup Calculator"

That'll get you real darn close.


If you're on stock tires, it looks like your error would be roughly 18.3%

motokid wrote:

Go here: click me

Under "Products" Then under "SpeedoDRD" you'll find "Setup Calculator"

That'll get you real darn close.


If you're on stock tires, it looks like your error would be roughly 18.3%

Thanks for that, I was on that site earlier and only the home worked, every other page timed out but all good now

the defalt seems to be set up for the WR250X, I had the change the stock rear sprocket to 43 and both tyres to 18"

stock R tyres are 120/80,
my D606's are 120/90, i put down /87,

I got 13.6%