Advertisement

Sign up for our newsletter

Advertisement

What is a gravel bike? Everything you need to know

Joseph Delves
6 Dec 2021

An introduction to the hottest and fastest growing riding discipline

Gravel bikes are dreadfully trendy. Riding on surfaces other than paved roads is hardly new, of course, but what has changed is the variety of bikes, events, and articles dedicated to helping you do it.

But what is gravel riding? At its most basic, a gravel bike is a drop handlebar bicycle capable of riding on unpaved surfaces. Gravel riding is any use you choose to put that bicycle to besides that typically considered road riding.

At one end, this could be pottering about on forest fire roads, green lanes and semi-paved byways in search of nothing more audacious than a good lunch.

At the other, it could be shooting across the plains of Kansas at the head of the 200-mile Unbound Gravel race.

In between fall many sub-genres, including bikepacking, adventure touring, or what might be termed 'mucking about on bikes'.

Despite gravel becoming a catch-all term, the terrain involved can be anything from sedate waymarked cycle routes suitable for families to remote trails clinging to the sides of little-traversed mountains.

Already comfortable with the definitions? Head straight to our comprehensive guide to the best gravel bikes. Otherwise, read on.

What is a gravel bike?

So what makes a gravel bike? Generally, any drop handlebar bike with tyres wide and grippy enough to ride off-road comfortably could work as a gravel bike.

Of course, machines specifically marketed as gravel bikes tend to have a few unifying features, key among them being the clearance for these wider off-road-capable tyres.

On top of this, their geometry will often be more relaxed for stability on loose surfaces. With the expectation of slightly lower speeds and slightly harder going terrain, gearing is often easier.

Focussed more on providing a wider overall range than smaller jumps between gears, single chainring or 1× drivetrains are popular because of their simplicity.

Handlebars tend to be wide for added control, while the drops of the bars are often flared outward for greater confidence on technical terrain. For reliability, power, and added clearance, disc brakes are almost universal.

Across what is a truly diverse segment, many higher-end frames will be carbon fibre, with some more adventure orientated gravel bikes using high-grade steel.

More affordable bikes will have aluminium frames, on the other hand, which can also be a good choice when paired with high-volume gravel tyres.

Plenty of gravel riders will also be interested in bikepacking, a form of lightweight off-road touring that usually uses soft bikepacking bags rather than traditional rack-mounted panniers.

This means many gravel bikes will have extra mounts for luggage, additional bottles and other accessories. At the other end of the spectrum, some bikes go as light and aggressive as possible, even eschewing practical features like mudguard (fender) mounts.

A genre that crosses over with many others, most gravel bikes will also work well on the road with a swap to road bike tyres, transforming them into excellent commuters or tarmac-based tourers.

Gravel bikes also have much in common with the bikes used for cyclocross racing, a kind of short-course off-road racing, and a cyclocross bike can work well as a fun gravel bike even if it's not specifically aimed at the discipline. 

At the more extreme end of the spectrum, some gravel bikes now include suspension, dropper seatposts, massively wide tyres, and 650b wheels, all formerly the preserve of mountain bikes.

Either way, one thing that unities almost all gravel riders is a preference for mountain bike-style shoes and SPD-style pedals rather than more flimsy and difficult to walk in road-going variants.

Gravel bike components

With gravel having gone from fringe to mainstream in short order, almost every bike maker now offers at least one gravel model. Some firms like Bombtrack or Salsa have even come to specialise almost exclusively in gravel bikes. None of this has escaped the notice of the big component makers.

Shimano got on board the trend early with its dedicated GRX gravel groupset. Campagnolo followed suit with its 13-speed Ekar system. As a multifaceted company, SRAM has not only launched wide-ratio XPLR gravel groupsets across several price points, but its sibling company Rockshox now produces gravel-specific suspension, while its wheelmaker Zipp has done the same with its carbon 101 wheels.

Open U.P. tyre clearance

Previously hard to come by, dedicated gravel tyres now take varied forms and can be had in many different widths and diameters. Components made specifically for gravel have also become more numerous.

These span everything from bars and saddles to jerseys and shoes. As with all trends, the advantages of products with the now mod-ish 'gravel' suffix added can vary drastically.

Want to get up to speed with your bicycle terminology? You can find our guide to identifying every part of a bike here

What is gravel riding?

The term gravel was arrived at to evoke the wide unmetalled roads that cross the American mid-west. These unadopted byways don't really have a direct equivalent in the UK.

However, the UK does have a plentiful supply of greenways, bridleways, fire roads, and singletrack and other ridable paths.

Unified by their lack of a solid surface and absence of motor traffic, they make a fabulous and low-stress alternative to riding on the road. Often available right on your doorstep, a little bit of hunting on Google Maps or Strava will probably reveal plenty nearby.

If you're prepared to travel a bit further, the UK also offers many exceptional off-road rides, from the competitive Dirty Reiver in the remote Keilder Forest to the King Alfred's Way route just a short train journey from London.

Head to mainland Europe and you'll often find many of the most famous mountains have little-used access paths that match those used by roadies to make the summit.

You can find some of our favourite gravel rides here:

Should I buy a gravel bike?

Yes! First, you can never have too many bikes. Secondly, if you can only have one bike, there's an excellent argument for making it a gravel bike.

For one thing, a gravel bike won't limit where you can ride. If you can point to it on the map, you can probably take it on.

At the same time, a gravel bike won't be excessively slow on the road either. Letting you flit between tarmac and dirt, you'll be able to explore wherever you choose. In fact, with a change of tyres, lighter gravel bikes will easily keep up with all but the raciest of road bikes.

Beyond being capable on multiple surfaces, gravel bikes also go big on versatility. Many will have mounts for mudguards, racks and other accessories, making them great for commuting and touring.

Gearing tends to be low maintenance and easy to spin so you're unlikely ever to have to get off and push on steep hills, while components are designed for durability and tend to hold up well over time.

Getting away from traffic also makes them a great initiation to riding, either for yourself or if you're introducing kids or inexperienced adults to life on two wheels.

Above all, gravel bikes are fun.

What gravel bike should I buy?

As with any bike, the first questions to ask yourself are what do you want to do with your new bike and how much are you prepared to pay for it?

Think of any bicycle like the centre of a Venn diagram. It will overlay many different qualities in different proportions. If you want a racy gravel bike that will also be legitimately quick on the road, you're probably going to be looking at the opposite end of the spectrum to gravel bikes that can also mix it up on aggressive forest trails.

Alternatively, suppose you want to go on backcountry touring missions while carrying every conceivable piece of bikepacking luggage. In that case, you're likely to be looking at something that will be more ponderous should you later apply it to the tarmac.

Inherently user-friendly, most gravel bikes will be stable, relatively upright, and have easy gearing. However, as with road bikes, gravel bikes still come in various guises.

This means some will be more upright than others. This can be great if you have limited flexibility or prioritise confident handling. At the same time, if you want to win yourself some gravel races, something lower and more aggressive will be quicker.

Much of this also comes down to the question of 'gnar factor’, a term we just made up. Gnar factor describes how aggressive the terrain can get before things get scary.

On a gravel bike with suspension, a dropper post, plus-size tyres, and oversized disc rotors, you're edging into mountain bike territory and will be able to ride challenging trails if you've got the skill.

However, such a bike will be heavier and and it'll be much slower on smoother surfaces than something with thinner tyres and a more stripped-back kit list.

Do you want to go fast on the smooth stuff or add confidence on the irregular sections? The trick when choosing a bike is to hit the spot closest to the riding you'll be doing most often.

Happily, though, gravel bikes will do most things relatively competently, meaning you can't go too far wrong. They’ll generally manage everything from gravel racing and exploring, to road-going duties, by way of backpacking or even cyclocross racing without complaint.

Read our comprehensive guide to buying your first gravel bike here, along with some of what we consider to be the best models on the market here.