Bicycle wheels come in a wide range of sizes from 12" wheels found on smaller Kids Bikes to larger 29" Mountain Bike and 700c Road Bike wheels. Larger wheels are normally faster and more stable at speed and their larger contact patch improves grip too. Smaller wheels are normally lighter, more manoeuvrable and have quicker acceleration.
Wheel sizes are defined by the country that first popularised the style of bike that used them - so you'll see some imperial and some metric measurements listed. Wiggle includes the ISO standard in brackets after each for ease of comparison.
Ritchey is well known for ingenious mountain bikes and parts, but Tom Ritchey was building world class road frames and rethinking every part of the road bike as early as 1974---long before mountain biking came along. After decades of refinement, Ritchey road components are the lightest, strongest and highest quality parts available, and race proven by top professional teams in the world's toughest pro races. Look for Ritchey components on team bikes in the Tour de France, Giro d'Italia, World Championships and Spring Classics, as well as countless other races.