CUSHCORE TIRE INSERTS SET 27. 5"Hold Up, Wait A Minute, Let Me Put Some Cush Up In It Cush Core is an engineered foam insert that mounts inside a mountain bike tire. It divides the inner volume of the tire in half, with air underneath the tread and the Cush Core insert next to the rim. The purpose of Cushcore is to improve the ride quality of your bike. It is not just for flat protection. Cush Core absorbs shock, stops deflection off obstacles, reduces vibration, and stabilizes the tire against roll and squirm. Think of it as suspension for your tires designed to give you a faster, smoother ride. This system is designed to be used with tubeless-ready or tubeless converted mountain bike rims and tires. Cush Core is compatible with tubeless tire sealants. Cush Core is sold as a set and is designed for use in both front and rear wheels. Specially designed tubeless air valves are included with each set. The air valve allows air to move through the valve without becoming obstructed by the insert. Features Compatible with 27. 5" wheels and tires Provides protection to both the tire and rim Improves ride quality by acting as tire suspension | Cushcore | Tire Inserts Kit 27. 5" Xc, 1. 8-2. 4" Insert & Valves