I've recently completed a track day on these tires and comparing them to the metzeler racetecs I was on these are pretty much on par! I was very impressed with these for a road tire they're possibly the best I've ever had! I've hated all bridgestones in the past but they have definitely got these spot on, would recommend to anyone. Have pics from track with my peg down if you need further convincing :)

The first set of Bridgestone that i am really happy with them . Very sticky in twisting roads and good enough in racetrack as well. Wear is very good and warm up is quick also. The only bad experience i had , .was with the pedestrian crossing lines , very slippery on them..

Great tires for high demanding bikes and bikers, the quality the rubber is excellent if you are one of those extreme bikers that wanna lean yourself daily at angles over 50 degrees, the tire feel with the road is funtastic. It doesnt last much 7.000km was the most i could take out of this tire but it was 1500km to many of what they really can assure, the center of the tire its extremely soft so if you do alot of straights and lean max around the 35 to 40 degrees and daily use less then 35 be prepared to have a square tire after 2500 3000 km, the tire is magnificent on dry and thats about it, wont be getting it again there are better options at a lower price for average sport usage that will last alot longer then this one without performance decrease on a middleweight naked. BMW F900R

Have YOU got experience with the Bridgestone Battlax Hypersport S21? Help millions of other tire buyers

Review your Bridgestone Battlax Hypersport S21 >

Excellent tire

I recently purchased a pair of these for my 05 R1. Despite the stock rear being a 190/50, I went for the 190/55.

160 miles in (60 of that were rapid laps around a brand new set of national speed limit roundabouts on a dry day averaging 22 degrees centigrade before writing this) and I am already extremely happy with them. They have more grip now than my previous Rosso II’s ever did and feel phenomenal round the bends when they have even been scrubbed fully in yet.

Part will be down to the different aspect ratio sure. (if you have the same bike you must pick up this size.)
But a lot of it is down to just how good the tires are.

This is of course subject to change. And I will update the unknown But so far I would definitely recommend them for the sheer pleasure they provide alone.