Gravel bikes v N+1 — is a fat tyre bike the best alternative to a fleet?

Do gravel bikes scupper the old gag that if you have N bikes now, the right number of bikes to own is N+1? Unless you're racing, a gravel bike could be the single bike you need: quick, rugged and also capable of carrying loads. Here's why.

First of all, don't be put off by the 'gravel bike' label. There might not be many gravel roads around your way but the vast majority of mountain bikes don't get ridden on mountains, most race bikes are never raced... Gravel bikes are great for a whole lot more than riding on gravel.

Check out our gravel and adventure bike reviews

You'll hear the term 'adventure bike' bandied about a lot too. Pedigree gravel bikes are designed for racing on gravel roads, which is largely a US phenomenon, while adventure bikes are more about exploring and maybe carrying enough stuff with you to stay away overnight or longer. In truth, the two categories merge, particularly here in the UK where we don't have a huge gravel racing scene. Bike brands have taken elements from each and combined them to offer you the best of both worlds. And in a battle of terminology that reminds us of 'mountain bike' v 'all terrain bike' back in the 1980s, 'gravel bike' is mostly winning, so that's what we'll mostly call them.

A gravel bike is in many ways a combination of an endurance road bike and a cyclocross bike. It's designed to be fast and efficient and also burly, making it the perfect option for those who want the option of exploring dirt roads, forest roads and the occasional bridleway as well as riding on Tarmac. 

Key features include a dropped handlebar, tyres that are fatter and knobblier than you'll find on a standard road bike, and disc brakes. These bikes usually have mounts for mudguards and racks so you can use them for commuting and touring too. 

Take a look at 22 of the best gravel & adventure bikes

If you want one bike that's capable of handling a whole bunch of different types of riding, you should definitely consider a gravel/adventure bike.

Ride position

It's difficult to make generalisations about gravel/adventure bike geometry because they're so varied but many people prefer the ride position of this kind of bike because it tends to be a little more relaxed than that of a standard road bike. The head tube is generally a little longer, the stack height (the vertical distance from the centre of the bottom bracket to the top of the head tube) taller and the reach (the horizontal distance between those points) shorter.

Take the Specialized Diverge Expert Carbon, for example. The 54cm model has a 116mm head tube (though the Future Shock widgetry in the steerer raises the bars quite a bit), a stack of 592mm and a reach of 383mm, putting you into a fairly upright ride position without much strain on your back or neck.

Gravel/adventure bikes often have a head angle that's slacker than that of a normal road bike – the Specialized Diverge Expert Carbon's is 71.25°, for instance – and the steering is a little less twitchy. Bottom brackets tend to be low and wheelbases long in order to add stability, and sloping top tubes are common, reducing the standover height.

These features help to make a gravel/adventure bike comfortable whether you're riding on rough gravel roads or asphalt.

Mudguards and ability to carry loads

Many manufacturers spec mudguard/rack mounts on their gravel/adventure bikes.

The Orro Terra C GRX800 that we reviewed, for example, has neatly positioned mudguard eyelets front and rear that will come in useful if you want to use the bike for all-weather commuting.

You also get rack mounts at the back that will help if you're lugging kit to and from work or doing the adventure thing and having a night away in the back of beyond.

Brakes

Gravel/adventure bikes are equipped with disc brakes. These have been dominant in mountain biking for years and have become more popular on the road recently because of the easily controlled power on offer. 

Many people find that disc brakes, especially hydraulic disc brakes, instil extra confidence when riding over rough surfaces, particularly with a heavy-laden bike. Plus, with the braking surface further from the road, disc brakes are less affected than rim brakes by wet conditions.

The Vitus Substance CRS-2 that we reviewed recently, for example, is equipped with Shimano GRX hydraulic disc brakes. 

Reviewer Stu Kerton said, "the braking – Vitus has specced RT56 160mm rotors front and rear – is impressively powerful so you can just use one finger on the flat section of the lever to control your speed."

Tyres

With no rim brake callipers and plenty of frame and fork clearance, gravel bikes can take far larger tyres than most road bikes and this can make a massive difference to your comfort.

The Kona Rove LTD we reviewed came with 47mm-wide tyres fitted to 650b wheels, the Mason ISO will take 60mm-wide tyres on 700c wheels, and there are bikes out there that will take even wider.

In contrast, most road bikes with rim brakes will take tyres up to 28mm (sometimes less) and endurance road bikes with disc brakes tend to accept tyres up to about 32mm. That might be enough for short sections of well-maintained gravel or towpath but you'll want more air between you and any really rough ground.

Tyre choice depends on the riding you're planning. You can fit lightweight and fast 25mm or 28mm tyres if you're going to be on asphalt all day, swap to something like a 35mm tyre if you're going to encounter some gravel and/or dirt, and go for something knobblier and wider if conditions are going to be more demanding.

Swapping tyres on and off your rims is a bit of a faff, especially if you're doing it frequently, so a couple of sets of wheels fitted with different tyres will make things easier if you can handle the expense. Changing wheels is quicker and easier than switching tyres. You could have wheels fitted with skinny road tyres for the daily commute and other wheels fitted with dedicated gravel tyres for weekend jaunts, for instance.

Check out 16 of the best gravel and adventure tyres

Gears

Gravel/adventure bikes come with many different gear setups so you're bound to find something that's to your liking. 

Many of us realised early on that your typical 50/34 compact chainset was silly on a gravel bike, and almost all manufacturers now seem to agree. Chainsets with 48/32 and 46/30 rings are common, dropping the overall ratios to give more gears for climbing on steep, loose surfaces. Cube's NuRoad Race FE is a good example, combining a 46/30 Shimano GRX chainset with an 11-34 cassette.

The most common alternative to a wide-range double chainring setup is a  single chainring with a very wide-range cassette. Known as a 1X (say 'one-by) setup, this is the way mountain bike gearing has worked for the last few years and you'll find it on Merida's heavily mountain bike-influenced Silex+ 6000. With typically a 38- or 40-tooth chainring and 11-42 sprockets, this doesn't give quite the wide range of a double set-up, but it's less complicated. You just go up or down the cassette and when you run out of gears you coast or get off and push.

The best option for you comes down to the terrain you'll be riding, the type of gear you like to push, and whether you're likely to be lugging heavy loads.

Find out how to get ultra-low gearing for gravel bike adventures

Riding off the beaten track

Gravel/adventure bikes are great for rough roads — that's what they're designed for. They can handle gravel tracks, forest roads, towpaths and even a bit of bridleway action, depending on the surface and the tyres fitted, where skinny-tyred road bikes would struggle. 

Some gravel/adventure bikes can cope with more extreme conditions than others. The Marin Gestalt X11, for example, has many features commonly associated with mountain bikes.

"A wide bar and short stem, sloping top tube, dropper post, wide tyres and relaxed geometry mean that when you swap the smooth for the rough, bumpy and technical the Gestalt X11 is right at home, unfazed by challenging terrain that can sometimes have other gravel bikes all in a twist," said Dave Arthur in our review.

Road riding

You're not going to win your local crit aboard a gravel/adventure bike but you might be surprised at how quickly you're able to ride on the road. In most cases, your ride position won't be a whole lot more upright than on an endurance road bike and you'll have a good spread of gears to keep you moving efficiently. A gravel/adventure bike is a great option for winter training but its use on the road needn't be confined to that.

Granted, big, knobbly tyres that are good for providing grip on tracks won't necessarily roll fast on asphalt, so it makes sense to have a couple of sets on the go at any time, swapping between them according to the surfaces that you're going to ride. Plus, there's the advantage that a gravel/adventure bike allows you to nip along non-asphalt sections – a short bit of towpath, for example, or a stony track – to save time or cut out a nasty section of road.

In his review of the Orbea Terra M21-D 19, Dave Arthur said, "The low weight and high stiffness [give it an] almost road race bike-like responses on the road, yet it's stable and controlled on rough and loose surfaces."

Commuting

Gravel/adventure bikes are burly enough to handle the daily commute and their disc brakes will perform well whatever the weather. The low gears are handy for riding in traffic and most have mounts for racks so carrying all the gubbins you need for the day isn't a problem.

Most bikes of this genre come with mudguard mounts too — a real bonus for making sure you arrive at work at least reasonably dry when the weather turns against you.

The Kona Rove DL comes fitted with mudguards and reviewer Stu Kerton said that as well as being a blast on and off the beaten track (with a change of tyres), it would make a solid workhorse for the daily commute. 

Touring

There are people out there who will tell you that adventure biking is essentially re-badged touring, and there's some truth in that although adventure bikes are generally more off-road capable than traditional touring bikes largely thanks to disc brakes and the ability to take wider tyres. 

An adventure bike's baggage carrying capability allows you to load it up with everything that you need for a night (or several nights) away, while the low gears allow you to pedal comfortably with that extra weight.

Check out why your next bike should be a touring bike 

Cyclocross

Gravel/adventure bikes are similar to cyclo-cross bikes in many ways, but usually have steadier handling for all-day riding and a wider gear range. That said, if you fancy a go at racing cyclocross, a gravel/adventure bike will get you started.

Read 6 reasons why you should try cyclocross this winter