Quick question guys, i heard that doing the sprocket mod on a 35 (bigger rear and smaller front for example ) puts the speedo off ... Is this true and is it worth doing? Bike goes good so probably wont do it but just a thought

Yes it will put the speedo off slightly as the speedo drive is taken from the front sprocket

does it say im going slower or faster than the actual speed im doing?

I have no idea, best to find a speed gun or something to test it.

Smaller front or bigger rear = over reading speedo

Bigger front or smaller rear = under reading speedo

Drunkn Munky wrote:Smaller front or bigger rear = over reading speedo

Bigger front or smaller rear = under reading speedo

what if i change both sprockets? will it be normal?

No, any change to the sprockets will put your speedo off unless you change them to give the same ratio as the standard setup(if thats possible) but thats pretty pointless isn't it.

Follow someone in a car doing 30mph,Make a note of the needle position on your clock,
Put an MPH graph on the lens with the 30 mph covering that spot.

Or even better - ride with a gps to work out where 30 mph is - car's speedo may be wrong too

don't worry about it - it reads faster than you are going, so as long as you hit your 30/40 limits you will be right...