ROAR outlaw ribbed front tires for SC competition
ROAR has amended the tire rules in the Short Course category to specifically exclude the use of ribbed front tires. Use of ribbed front tires is inconsistent with a category that has achieved most of its popularity on the basis of scale appearance. Therefore, ROAR has decided not to allow use of this type of tire on this basis.
Source: ROAR [roarracing.com]