tubular tyres: Tubular tyres are cycle tyres that have the inner tube permanently stitched inside the casing. They are held in place using glue or glue-tape, and are affixed to rims which lack the sidewalls characteristic of a hook-bead rim. Tubulars take very high pressure (up to 10 bar or 145 psi, or higher for racing and track-specific tires) which reduces their rolling resistance. They typically result in wheelsets that are lower in overall weight than comparable clincher wheels, because of the shape of the rim, the tire construction, and the lack of rim strips. Tubulars can be ridden at lower pressures than clinchers without the risk of pinch flats, because of the shape of the rim. This makes them well-suited to cyclo-cross, especially in muddy conditions where low tire pressures are used. However, they are difficult to replace and repair and are generally more expensive than clinchers. Also called sew-ups, tubies, or tub.