You can take 100 or 20 miles to scrub a set of tyres the idea is to remove the releasing agent (shiny surface) from the tyre best, bet is to lean around corners a little at a time taking it steady with the throttle and not steering too hard till you are up to the edge, once you are up to 10mm wide chicken strips boths side you should easily be good to go.
Unless you are a complete lunatic on the road the front tyre will always have about 5mm both sides so don't worry about it.
ALWAYS MAKE SURE YOU WARM YOUR TYRES.
I replace my tyres when the profile goes as I hate riding my bike when the steering feels crap.
I hate the rain but Avon do a road legal wet tyre Azaro Pro-Xtreme Rain that is supposed to be good enough for knee down action if you are totally off your rocker.
http://www.avon-tyres.co.uk/motorcyc...showtyre&id=14