The World-class Continental Competition tubular now uses Black Chili compound and Vectran flat-protection breaker. The Black Chili compound uses smaller carbon particles which have more contact points for less rolling resistance and form more easily around imperfections in the road surface. The smaller particles also fit closer together for longer tread life. The use of Vectran not only improves flat resistance, it also reduces weight by approximately 15 grams, reduces rolling resistance, and improves ride comfort. 650c (571 ISO) Sizes.
A guide to common bike tire sizes and how to find the tires that will fit your bike.
Understanding older bicycle tire sizes.
A useful chart for determining the tire size you need for your bicycle.
Tips for proper bicycle tire mounting and tire safety.
A guide to understanding tire width.
A guide to understanding bicycle tire tread patterns and what you should look for.