tyre ratings
The letter denotes the speed rating of the tyre, so as long the tyre is suitable for the speeds the bike is capable of their will no real noticable difference between 'H' or 'V' rated tyres or any other for that matter.
Here they are for the hard of sleeping!
Speed Symbol "N" For vehicles with a speed capability not exceeding 140 Km/h (88 Mph)
Speed Symbol "P" For vehicles with a speed capability not exceeding 150 Km/h (94 Mph)
Speed Symbol "Q" For vehicles with a speed capability not exceeding 160 Km/h (100 Mph)
Speed Symbol "R" For vehicles with a speed capability not exceeding 170 Km/h (106 Mph)
Speed Symbol "S" For vehicles with a speed capability not exceeding 180 Km/h (113 Mph)
Speed Symbol "T" For vehicles with a speed capability not exceeding 190 Km/h (119 Mph)
Speed Symbol "U" For vehicles with a speed capability not exceeding 200 Km/h (125 Mph)
Speed Symbol "H" For vehicles with a speed capability not exceeding 210 Km/h (130 Mph)
Speed Category "VR" For vehicles having speed capability over 210 Km/h (e.g. 195.50 VR 15)
Speed Category "ZR" For vehicles with a speed capability over 240 Km/h (e.g. 205.40 ZR 17)
Speed Symbol "V" For vehicles with a speed capability not exceeding 240 Km/h (e.g. 225.55 R 15 91V)
Speed Symbol "W" For vehicles having speed capability not exceeding 270 Km/h (e.g. 225.60 R 15 96W)
Speed Symbol "Y" For vehicles having speed capability not exceeding 300 Km/h (e.g. 275.40 R 18 94Y)
ZR+ Speed Symbol "W" Tyres marked with both designations for vehicles with speed capability over 240 Km/h but not exceeding 270 Km/h
ZR+ Speed Symbol "Y" Tyres marked with both designations for vehicles with speed capability over 240 Km/h but not exceeding 300 Km/h