I have decided to lower my gearing going 2 teeth up on the rear sporket. Had a go on ChrisD’s ZX6 with similar gearing set up and its made the acceleration so much better and noticably stronger the whole way through the rev range! Oh and it means the fronts easier to get airbone off the throttle in first! The deed shall be done Saturday 
do you have to adjust the length of your chain when changing teeth on sprockets?
It depends if the chain has enough adjustment slack to fit the new bigger sprocket. In my case it does. The normal thing is to go down a tooth on the front but that changes the speedo reading and also stresses the front sprocket more. I have got a nail in my back tire at the mo so while the wheel is off I will get the sprocket changed at the same time.
I was tempted to go up 4 teeth on the back why do you need 160mph top end living in wembley hey lol
All depends on your current mileage/condition of your chain and sprocks. The proper way to do it is get a full kit as if your chain is quite worn it will kill a new sprocket!.. I am going down 1 on the front shortly, should be interesting…
Nice one Terry. You should try -1 on the front, it’s equivilent to +3 on the rear and means you can keep the same chain most of the time. Much stronger acceleration
I went -1 on the front and +2 on the back
I’ve not had to buy a new front tyre since 
Well at the mo the front will come with a heavy tug in first its just lacking a little power so with lowered gearing it should pop up nice and sweet!
Yep, -1 +2 is what i did - AFAM kit, loved it…
Terry, I got -1+2 - mental but bear in mind that your bike will show 100mph on the clock and you will be doing only around 80ish… Safer for your license, lol
Thats why I want to change just the rear sproket as I have been told that it doesnt mess with the speedo. I could do without it reading incorrect.
I do this mod religiously whatever bike, its also good for 2 up aswell. Have fun
Your speedo will still change, Terry, this will always happen if you change from the standard gearing. It doesn’t vary much though. Mine’s quite aggressive at -1+2, and I read 90mph at 70. Just -1 will throw it out about 10%.
But doesnt it measure how fast the front sproket turns to read the speed? So if I leave the front sprocket alone and change the back it shouldn’t change the reading should it?
It depends on he bike, i just dropped my bike with my mechanic and he said that the speedo wont be affected by me going down a tooth on my front sprocket as he speedo readin is done from the gear box on my bike …i thinks thats what he said…I should ahve mine back 2mrw…poss in time for the ace lol!
Oh and im getting my whole set changed front rear and chain, this seems to be the best thing to do from what ive read!
It does affect the reading mate believe me, ive got +2 on the road bike and it reads about 78MPH when at 70 MPH (tested with the missus riding her B1 next to me on the motorway)
you are right tho the reading is taken from the front sprocket but if you imagine changing gear on a mountain bike the bigger the rear cog the faster the chain will travel… personally i wouldnt go any more than +2 on a road bike as it can make it too buzzy on the road!
and the trackbike is well out as its got -1 +2 on it… Muaghahahahaha… 