If you are currently running at a sprint track, in Parilla Leopard (2004 IKF National Class #10) or the Region 11 NorCal National Cup, the most likely road race crossover classes are...
 
 

IKF National Class #13 - TaG

 
Rule Differences...
 

Engine(s**):
 

Rotax 125 (Seal not required)
Parilla Leopard
Sonik VX125
Comer
Biland
BM Jaguar
Vortex Rok
Italsistem ML47H
 

Weight(s):
 

375 lbs
375 lbs
375 lbs
375 lbs
375 lbs
375 lbs
395 lbs
395 lbs
 

Tires:
 

No compound or manufacturer restrictions.  5" rim diameter maximum.
 

Race / Heats:
 

20 minute heats.
 

NCK Local Option Class #30 - West Coast TaG 125cc Sprint

 
Rule Differences...
 

Engine(s**):
 

Rotax 125 (Seal not required)
Parilla Leopard
Sonik VX125
Comer
Biland
BM Jaguar
Vortex Rok
Italsistem ML47H
 

Weight(s):
 

375 lbs
375 lbs
375 lbs
375 lbs
375 lbs
375 lbs
395 lbs
395 lbs
 

Tires:
 

No compound or manufacturer restrictions.  5" rim diameter maximum.
 

Race / Heats:
 

30 minute race.