What a cyclocross bike is, and what it is not
A cyclocross bike is a drop-bar bike with clearance for 33mm tyres, a higher bottom bracket than a road bike so you can pedal through ruts without striking them, and cantilever or disc brakes for mud clearance. The geometry is shorter, tighter and more responsive than a gravel bike. Cyclocross bikes are designed for an hour of flat-out racing, not for long days in the saddle.
A gravel bike will take far wider tyres, usually up to 45mm or 50mm, and has a longer wheelbase for stability. If you want one bike for long weekend rides on mixed surfaces, a gravel bike is almost always the right choice. Cyclocross bikes reward riders who actually race, or riders who value the snappy, quick handling for shorter fitness rides in bad weather.
The Union Cycliste Internationale rulebook limits cyclocross race tyres to 33mm, which is why almost every true cyclocross bike is built around that clearance. Plenty of older cyclocross bikes fit tyres up to 35mm with care, but any listing that advertises room for 40mm or wider is really a gravel bike with a cyclocross badge.
Typical prices on the used market
Under six hundred pounds, the cyclocross market is mostly older aluminium bikes with cantilever brakes and 10 speed drivetrains. These are genuinely fun winter bikes if the frame is sound. Cantilevers are a little fiddly to set up but they work fine once adjusted.
Six hundred to one thousand two hundred pounds buys clean late-model cyclocross bikes with disc brakes, usually hydraulic, and 11 speed drivetrains from Shimano or SRAM. Frames at this price are often carbon from smaller brands, or aluminium from the big ones. This is the sweet spot for most buyers.
