What Is A Cyclocross Bike? CX Bikes Explained

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Cyclocross is one of the most hardcore cycling disciplines, requiring excellent handling, power, and even running.

The riders need to traverse some extremely tough terrain, including steep banks, sand, mud, and sometimes snow. Not only that but there are often many obstacles on the courses, meaning the riders have to dismount and run with their bikes.

But what is a cyclocross bike? And how does it differ from a gravel or road bike?

Fundamentally, cyclocross bikes look very similar to road bikes, and would be difficult to tell apart to the untrained eye. However, the CX bike will likely have slightly wider tires, greater tire clearance on a more robust frame, and often a slightly more relaxed geometry.

Older cyclocross bikes are also likely to be fitted with cantilever brakes which deal with mud better than the caliper rim brakes traditionally used on road bikes, although modern bikes in both disciplines now tend to favor disc brakes.

To get you up to speed, we’ll be covering:

  • What Is Cyclocross?
  • What Is A Cyclocross Bike?
  • Is A Cyclocross Bike The Same As A Gravel Bike?
  • Do You Need A CX Bike To Take Part?

Ready for the lowdown on cyclocross bikes?

Let’s get started!

What Is A Cyclocross Bike: Title Image

What Is Cyclocross?

Cyclocross – also called CX or ‘cross – is one of the oldest disciplines in cycling.

With origins as far back as the late 19th century, cyclists used to race each other between towns in Belgium and France. The routes they took would include roads, fields, steps, styles, and everything in between.

The discipline has come a long way since these informal races, and the events are far more organized in modern cycling, with World Championships, a World Cup, plenty of National Championships, and endless amateur events.

Cyclocross is a discipline that tests a rider’s abilities to the max. The courses are short, closed, and tight. They are mostly off-road, including sections of extremely loose surfaces and obstacles that riders need to dismount to pass.

Don’t be fooled by the off-road nature of the discipline; it is an extremely fast-paced race. Riders don’t by any means prioritize comfort, and aerodynamics remains a major consideration.

The ‘cross season is September-February in the Northern hemisphere, and so adverse weather conditions often make an appearance during the events. This is very much a part of the sport, however.

Cyclists battling heavy rain, strong winds, and even snow are a common sight in the sport.

A cyclocross race hurtling around a bend.

What Is A Cyclocross Bike?

Given the seemingly contradictory concepts of high-speed, aerodynamics-focused racing with loose, bumpy, off-road terrain littered with obstacles, you might be wondering what on Earth a cyclocross bike looks like.

Well, a CX bike wouldn’t look out of place on the road.

To reach the blistering speeds necessary, ‘cross bikes have relatively thin tires, drop handlebars, and a similar geometry to a road bike.

The handlebars are often fairly narrow, and the tires can be anywhere between 30-38 mm, but most pros use something between 32-35 mm. These factors make cyclocross bikes pretty aerodynamic, especially when compared with mountain bikes.

To tackle the brutal terrain, cyclocross bikes use 700c wheels for increased rollover. This means that the wheel will more easily gobble up small obstacles in its path, and have the ability to take on bigger ones than a 650b wheel without lifting off the ground.

They also use tires with a very knobbly tread pattern. This is to provide extra traction on the loose terrain to stop their back wheel from slipping when riding down sand banks or slippery muddy slopes (although, it definitely still happens!)

The tread patterns of the tires usually have big central knobbles, relatively close together, with comparably sized ones at the sides, but further apart from each other to reduce mud build-up.

A collection of bike tires in a workshop.

At the highest level, you’ll never see anyone running clinchers with inner tubes. The risk of a pinch puncture is just far too great with such a setup, since the terrain often has sharp rocks and drops, and necessitates small jumps.

A pinch puncture is when the tire takes an impact and the inner tube is pushed against the rim, often piercing it in a characteristic “snake bite” pattern, with two small holes on either side. For this reason, clinchers with inner tubes require very high pressures.

Running a lower tire pressure has a number of advantages, and in the context of cyclocross, the most significant of these is the decreased rolling resistance off-road. A tire with some give will be able to absorb small obstacles in the course, rather than bounce over them.

These factors mean that you’ll pretty much exclusively see tubular or clincher tubeless setups in cyclocross.

The geometry of a CX bike is more similar to a road bike than a mountain bike, encouraging an aggressive riding position to decrease aerodynamic drag.

There are some differences, however, that contribute towards the compliance of the bike. They often have a more relaxed geometry than a racing bike, and although the riding position isn’t so dissimilar, it’s usually a little more relaxed.

An ever-so-slightly more upright position provides a shock-absorption effect on the bike in order to decrease the brain-shaking vertical vibrations you’d get with a road bike.

But these bikes really aren’t built for long days in the saddle. They are often not the most comfortable but allow the rider to reach and sustain high speeds over short races.

Close-up of a disc brake on a silver bike.

Since the terrain is so varied, CX bikes need a lot of braking power, and so tend to use disc brakes. Although they only really became popular on roadies over the past decade, disc brakes have been a fixture on CX machines for a while now.

The other advantage of disc brakes is that they’re far more resistant to wet conditions. If you’ve ever used rim brakes in a rain storm, you’ll know that their effectiveness decreases massively. Disc brakes don’t generally suffer from this condition-dependent effectivity.

The last, and arguably one of the most important features of a cyclocross bike is the weight. At the highest level, you’ll basically exclusively see carbon bikes on the course. This is to reduce the weight of the machine.

A light bike is essential in cyclocross. Firstly, the riders often need to dismount, pick up their bike, and run over an obstacle. That’s definitely not easy with a 15 kg steel bike.

Secondly, a lighter bike allows the rider to accelerate and decelerate more efficiently, which is necessary given the varied terrain and tight nature of the courses. It allows the rider to decelerate when approaching an obstacle or corner and accelerate quickly out of it.

A group of cyclocross riders carry their bikes up some steps.

Is A cyclocross bike the same as a gravel bike?

You may have just read this description of a cyclocross bike and asked “isn’t that just a gravel bike?”

Well, sort of. A cyclocross bike has many similarities to a gravel bike and you could definitely use a gravel bike in an amateur-level CX race without too many issues.

However, although they are pretty similar, there are in fact a few key differences.

A gravel bike usually has a more relaxed geometry than a CX bike. This allows for a more upright, comfortable riding position, and makes gravel bikes better suited for long days in the saddle and touring.

But of course, this does increase the drag on the rider, and 80% of drag in cycling comes from the rider – so your position on the bike is vital. If you’re traveling at relatively high speeds, this will be a noticeable difference.

A burgundy gravel bike skids along a path in autumn.

The handlebars of a gravel bike are often flared, allowing for a much wider arm position and more purchase on the steerer. This is because gravel bikes can be ridden in arguably more extreme scenarios such as MTB trails and you need to have exceptional handling to do so.

This, like everything else, comes with an aerodynamic penalty for gravel bikes.

The tires of a CX bike are also (usually) thinner than that of a gravel bike. This is again because a gravel bike is built to be as versatile as possible and needs to be able to tackle all sorts of terrain without dismounting.

However, wider tires do mean increased rolling resistance on less rough terrain. And cyclocross riders, being the speed demons that they are, are unwilling to accept such a penalty.

Two cyclocross riders come around a muddy bend.

Do you need a CX bike to take part?

The short answer: not necessarily.

Depending on the kit you have available to you, you might already have everything you need to zoom around a cyclocross course.

Although there are definitely differences, a gravel bike is probably your best bet as a substitute.

Overall, gravel bikes are pretty similar and with perhaps a few small adjustments to the setup of your gravel grinder, you should be able to ride ‘cross courses at pretty high speeds.

The most important and accessible of these is to put some slightly thinner tires on your bike. Most gravel bikes will have 38-45 mm tires which are a bit too thick for ‘cross. Dropping this down to around 32 or 34 mm will save you quite a few watts.

Even if you only have a road bike available to you, you still might not need to go and drop crazy amounts of cash on a dedicated cyclocross bike.

It’s worth seeing if it’s possible to convert your old roadie into a cyclocross machine. Check out this article for step-by-step instructions on how to make your very own ‘cross-conversion!

A mountain bike, on the other hand, is unlikely to be able to compete with the other riders on the course. If you’re very keen to enter some cyclocross races, then you might just need to bite the bullet and make the investment.

But whatever bike you choose for your first ‘cross race, you’re almost guaranteed a good time trying out this exhilarating, challenging sport!

Found this guide helpful? Check out more from the BikeTips experts below!

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Jack is an experienced cycling writer based in San Diego, California. Though he loves group rides on a road bike, his true passion is backcountry bikepacking trips. His greatest adventure so far has been cycling the length of the Carretera Austral in Chilean Patagonia, and the next bucket-list trip is already in the works. Jack has a collection of vintage steel racing bikes that he rides and painstakingly restores. The jewel in the crown is his Colnago Master X-Light.

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