RapidAir construction uses a two-ply casing that overlaps at the sidewalls instead of the traditional three-ply design that stacks material under the tread. That difference matters because material under the tread increases rolling resistance as the tire flexes with every rotation. The two-ply design puts less material where the tire contacts the road, which reduces energy loss while maintaining sidewall support where the plies overlap. The construction also creates a more supple contact patch that conforms to pavement texture, which improves mechanical grip without adding rubber compound or weight.

Specialized uses dual compounds in the tread—Gripton T2 in the center and Gripton T5 on the shoulders. The T2 compound in the center strip delivers lower rolling resistance on the straights where most of your contact happens, while the T5 compound on the shoulders provides grip when you're leaned over in corners. That split lets you run a fast compound where speed matters and a tackier compound where traction matters, rather than compromising with a single compound that does both jobs adequately. The 120 TPI casing contributes to the supple feel without sacrificing durability compared to higher thread count race casings that sacrifice puncture resistance for suppleness.

BlackBelt puncture protection uses a hybrid Kevlar breaker under the tread that Specialized claims delivers twelve percent more puncture protection than their previous aramid layer while reducing weight. The protection sits between the casing and the tread compound, stopping sharp objects before they penetrate through to the tube or sealant. For tubeless setups, the tire works with sealant to handle small punctures that make it through the BlackBelt layer. The tire mounts on both hooked and hookless rims, and Specialized reinforced the beads with Zylon material that exceeds hookless burst pressure standards by two hundred percent, which addresses safety concerns about tubeless tires on hookless rims.... Read More