Originally Posted by teadoggg

Most tubular tires do have an innertube, it's sewn up in the tire, though.

Tubular Clinchers are the jam. Yeah, there are little beadlike things that expand when the tire is pumped up, thus gripping the rim. The cool part about them is that regardless of the pressure in the tire, they are held on with the same force. This means, regardless of PSI ratings on the rim (e.g. some rims have a 140psi limit) you can inflate the tubular clinchers to 170, 200, whatever they're rated for. It's really a genius idea.