I'd ask around to see what HP requires wheel locks for safety reasons. The fastest I've run was in the tens w/o locks but with reduced tire pressure. Some guys run really low tire pressure and with very good grip, the chances for rim spin increases. In the mid 70s I ran an 852cc SOHC Honda four in the low 12s with a bald Dunlop K81 (with a tube) and about 18 psi in the rear. Never had the rim spin but once I did line up in a dragster's burnout patch and by the time I staged I had become glued to the pavement! I not only wheelied straight up, I red lighted. The bike actually rotated up w/o going farther than needed to trip the lights.