Geometry
Geometry
Cyclo-cross bikes typically have more relaxed angles than road machines to improve comfort and handling characteristics over tricky terrain, though how relaxed depends on the type of bike and its target rider.
A higher bottom bracket height improves clearance over rough ground and allows the rider to pedal through more corners, and a slacker headtube angle also improves control.
Increased clearance ensures the frame does not get clogged up with mud and allows the use of wider tyres. Stem length tends to be slightly shorter and handlebars wider than on comparably sized road bikes to improve handling off road.
A clean and wide triangle is required to allow the bike to be carried over a shoulder with ease, so some high-end, race-specific machines will forgo bottle cage mounts, though this is increasingly rare.
Cables are also typically routed along the top of the toptube, to keep them free of mud but also to avoid discomfort and damage when shouldering the bike.