I was having some issues with my rear Michelin Pilot Road 2, it is mated to a Pilot Power front. After running D207RR's which wore out I had these kicking around. I had took the Road 2 off soon after it was fitted as it was useless in the heat of Spain and their worn out roads.
I have been using these Michelins during the hottest months of summer (in England)and they have generally been fine although the rear was pretty poor in the wet.
Now the tarmac is starting to cool at night I have had even more issues with lack of grip on the rear. I dropped the pressure down to 31psi (from my normal 34) which helped a little. Then one night coming home from a friends the rear snapped out at around 65mph in fourth gear. As I wound the power on the bars crossed up and I thought I was off. I rode the last 3 miles of the 25mile journey home carefully and checked the tyres. The Pilot Power front was quite warm as usual bu the rear Road 2 was almost cold. Anyway I thought I would try siping the tyre as I was going to throw it away and get another Pilot Power. I read a lot on the internet, but nobody had really tried it on motorcycle tyres for the road. I checked out the Pilot road 3's and used the sipe design on those to point me in the right direction, as if done incorrectly it can ruin the tyre.
Using a stanley knife I cut 2-3mm slits in the tyre which is about half the trad depth. I tried to keep spacing between all the slits even and I made the go from tread to tread to aid cooling. The road 3's have holes at the ends and along the sipes for this but I don't have a tool to make them so used the tread. The slits I cut near the edges of the tyre don't go to any treads and are space in the middle of the existing tread. They are smaller cuts and the far edges of the tyre get the least use so overheating shouldn't be a problem.
Anyway I waited until late for the temperature to drop and just got back from a test ride. I didn't push the bike too hard but I will say that I had much more confidence in the rear and it didn't move at all where I opened it up. I stopped periodically to check the tyres temperature and found that it was running almost as hot as the front Pilot Power so it shouldn't hopefully try and highside again anytime soon.
The tyre will probably wear out faster now, but like I said I was going to throw it away anyhow. Rubber is cheaper than fixing metal and plastics, also less painful than fixing broken bones.
Moto GP swingarm, ZX10R led rear light, ZX10R wavey discs. Moto GP mass centralised exhaust, USD forks.