The Government is slow in upgrading their specs/qualifications about tires and the compatibility of the wheels.... When the regs were written .... there were NO Mtc's made with wheels that accepted Auto tires ..... So the regs just say NO MTC's can use " auto tires " period ..... However, if you dig into the regs it states that AUTO tires MUST be used on " J " style rims & wheel BEADS .... that's Exactly what our Spyders have (the same for HD Tri-glides) .... Eventually they will catch up - but I'm not holding my breath as to WHEN that will occur ...... Good Luck ... Mike