Vittoria Terreno Graphene 2.0 Mix Terrain Gravel Tyre - 700x38 Black Size:700x38c they have 6 channels cut

they have 6 channels cut into the base of the stem which allows free flow of sealant and air

– The Curve Control System® guarantees durability and an exceptional ride quality

Seals porous tyres and bead/rim gaps

As an endurance athlete (your events typically last more than two hours) you need to take in between 80-120g of carbohydrate per hour

Vittoria Terreno Graphene 2.0 Mix Terrain Gravel Tyre - 700x38 Black Size:700x38c they have 6 channels cutFor mixed terrain conditions Open shoulder lugs for secure off camber traction Traditional tread profile for smooth transitions across a broad range of terrain Size: 700x38 Anthracite Black