There is little doubt that choosing the right tyres for the terrain and conditions – and let’s not forget that all-important tyre pressure too (we’ll come back to that later), can make or break a ride.
With countless options available for gravel bikes, across two completely different wheel sizes, how do you choose which tyres are best for you?
Related questions you can explore with Ask Cyclist, our new AI search engine.
How to choose the right gravel bike tyres?
You need to begin by asking yourself a few questions. Starting with: on what surfaces are you going to ride most of the time?
It’s worth pointing out from the get-go that there is no one gravel tyre that can be all things to all riders and for all conditions, and so when it comes to choosing the best gravel tyres there is almost always likely to be a level of compromise somewhere that must be expected and accepted.
The best advice, then, is to choose the gravel tyre best suited to where you spend the majority of your time on the bike. There’s no point dragging a set of hefty knobblies around if you barely venture off the beaten path, and when you do it’s only on well-established and hard-packed surfaces.
By the same virtue, expect a white-knuckle ride if you get a bit ambitious with your route finding and your tyres are not well-suited to the task.
Your level of off road competence/experience will inevitably play a part in your tyre choice too. Less experienced riders will probably feel more comfortable erring on the side of caution and opting for a tyre that will offer a more confident feel on loose or slippery, muddy terrain, and accept the consequences to rolling speed on hard-packed, smoother trails or roads.
The two biggest decisions to make are width and tread pattern.
Tyre width
Tyre width directly influences a number of factors. Wider tyres have a larger air volume and so will potentially offer more cushioning (comfort) as that bigger pillow of air is more capable of isolating the rider from the bumps.
Crucial to understand here, though, is the relationship between air volume and pressure. Having a greater volume of air inside the tyre facilitates riding with a lower pressure without such high risk of damage to the tyre carcass or rim from impacts.
Another key consideration, then, is how this influences the tyre’s ability to provide grip. A wider tyre has a larger surface contact patch in the first instance – putting more rubber in contact with the ground to aid grip, but riding at a lower pressure enables the tyre to deform around objects – tree roots, stones, rocks, etc, which also massively enhances its ability to provide grip.
So, with a number of significant benefits, why don’t we just use wider tyres all the time? Well, there are some downsides to consider. Increased weight is probably the most important, especially as tyres are a large rotating mass, which means their weight has a bigger influence on bike handling (steering, braking and acceleration). There is also the fact that a wider tyre is more likely to increase drag (although not always!).
In the 700c wheel size the market seems to have settled on the range between 40-45mm as the most common for gravel tyres.
Many frames will not have clearance for anything larger than 700x42mm in any case. This is something that should also be considered. Make sure you check what your specific frame will accept prior to purchasing new treads.
Smaller 650b is an old French size that was popularised by touring cyclists, but was given a rebirth (as 27.5”) on mountain bikes.
Why use a smaller wheel size? The thinking is this: a 650b wheel (smaller diameter) can therefore accommodate a larger tyre (e.g. 47-51mm) and still have an almost equal overall rolling circumference as, say, a 700x40mm.
This does depend a lot on the individual tyre brand and rim combinations but as a rough guide this will be the case. Therefore, importantly, the geometry of the bike will not be affected by switching between two wheel sizes, but the performance of the tyres will change dramatically, due to the reasons discussed above regarding volume, pressure and grip, and result in a very different riding experience.
Tyre tread pattern
Generally speaking, gravel tyres only have a very small amount of tread working to help us, so that means the tread pattern is really crucial to the ride characteristics. There is much more to consider for an off-road tyre versus a road-only tyre.
A common mistake is to assume big knobbly treads must be the most grippy tyres. Not so. A very knobbly tread pattern doesn’t automatically mean it will offer the best grip in all circumstances. For instance, if you ride on very rocky terrain, a tyre with large aggressive knobs will not be able to ‘bite’ into the surface and so will not be able to work and provide grip optimally.
In fact they may provide less grip compared to a less aggressive tread design, which will not flex as much, plus puts more rubber surface area in contact with the ground.
Knobbly treads will work best when the ground is soft, as only then can the tread get the necessary ‘purchase’ into the terrain.
Soft ground conditions also throw up another consideration, that of how well a tread can ‘clear’ itself. If mud simply packs into a tyre tread (basically reducing its effectiveness and adding a lot of weight) but does not clear, it can be a big disadvantage to its performance, so a well-spaced tread design is preferable if your trail conditions have a lot of thick, claggy mud (e.g clay).
More loamy or sandy soils are likely to clear much better, and so tyre clogging is much less of an issue.
Gravel tyre categories
It will help to narrow down the choices, if we group tyres into the following sub-categories:
Fast rolling gravel tyres
Ideal for a mix of tarmac and predominantly smooth, well-made and hard-packed trails e.g. forest gravel roads, disused railways etc.
For many riders the ‘fast rolling’ element of a gravel tyre is still going to be very important as gravel riding is still about the sense of speed, just over more varied terrain, and definitely on tarmac at times too.
In this scenario a tread pattern with an almost continual patch of rubber created by a very closely spaced tread pattern will roll faster than a tyre with more spaced out knobs. It doesn’t have to be a solid strip, just closely spaced – almost connected – in the mid section.
A chevron pattern is quite effective as are file-treads to create fast rolling tyres and a stable feel for when the rider is splitting their time between road and off-road.
Some edge grip is useful for off-road excursions. That’s why many gravel tyres use a dense central portion but with low volume side knobs. It’s a good way to be able to do more with a single tyre choice.
When it comes to speed, tyre width is an important consideration. Narrower (e.g. 35mm) will likely be a bit faster and lighter too, if you have climbs to consider.
Cyclist's top pick
WTB Riddler: buy now from Sigma Sport for £60
Other picks in this group
WTB Venture: Buy now from Sigma Sports for £60
Hutchinson Touareg: Buy now from Decathlon for £34.99
Pirelli Cinturato Gravel H: Buy now from Tweeks Cycles for £48.74
Continental Terra Speed: Buy now from Tweeks Cycles for £55.96
Vittoria Terreno Dry: Buy now from Tweeks Cycles for £17.59
Schwalbe G-One Allround: Buy now from Tweeks Cycles for £32.20
Panaracer Gravel King: Buy now from Cyclestore for £26.99
Challenge Gravel Grinder: Buy now from Tweeks Cycles for £37.50
Michelin Power Gravel: Buy now from Decathlon for £37.99
Teravail Cannonball: Buy now from Tredz for £59.00
Mixed terrain gravel tyres
Mixed terrain but with more of an emphasis on off-road than road. Surfaces will be loose at times, but mostly hard ground e.g well-trodden paths, hard-packed sand, well-used forest trails.
To better cope with a variety of off-road trail conditions it’s advisable to move to a more separated tread pattern, with individual blocks or knobs, which allows them to work independently.
By spacing the tread pattern it will sacrifice a little rolling speed as we move from riding 'on' the tyre towards being 'in' the tyre. The separated ‘blocks’ have room to flex and therefore achieve grip on a given surface.
The size and height of the block is what is most crucial in influencing how a tyre performs. Too tall and it will flex too much, causing an unstable feel and a lot of additional drag on harder surfaces. Too chunky and it may feel too rigid, and of course will add weight too.
Tyre design is so much about getting the balance right. Dual-compound tyres are one solution, whereby a firmer rubber durometer in the mid-section will help reduce rolling resistance whilst a softer rubber compound can be used on the shoulder/edges of the tread for improved cornering grip.
Cyclist's top pick
Maxxis Ravager: Buy now from Tredz for £49.99
Other picks in this group
Schwalbe G-One Bite: Buy now from Tredz for £32.99
WTB Resolute: Buy now from Tredz for £58
WTB Raddler: Buy now from Tredz for £59.99
Continental Terra Trail: Buy now from Tredz for £37.99
Soft terrain gravel tyres
Soft terrain, e.g. mud, grass. The softer the terrain the more a less-populated knobbly tread design will work in your favour, with pronounced knobbles, spaced to bite into the ground.
The knobs are essentially working alone. The spaced tread pattern will shed dirt much more easily which is important in conditions where the soil is claggy, and would otherwise clog up the tread. The tread cannot perform optimally if it is clogged, so a key thing on this kind of tyre design for manufacturers to figure out is the exit points for the dirt. Dirt and mud must be able to be pushed out if the tread is to stay clear.
Softer compound rubber is really useful in tyres designed for muddy/wet conditions as it adds flex and improves grip, but as always there’s a balance to be struck. If the knobs flex too much this can make the ride feel really squirmy on harder surfaces.
Often this type of tyre is best kept for muddy, wet off-road rides, as the nature of the tread patterns make them less ideal for more varied terrains, and hard/fast conditions.
Cyclist's top pick
WTB Sendero: Buy now from Tredz for £60
Other top picks in this group
Pirelli Cinturato Gravel M: Buy now from Tweeks Cycles for £44.99
Teravail Rutland: Buy now from Tredz for £42
One for all?
As already mentioned it’s unlikely there could ever be a ‘Holy Grail’ of tyres that can do everything well, but if you could only own one gravel tyre (one pair, obviously) my choice would be the WTB Resolute in 700 x 42: this tyre is a superb all-rounder, very capable and able to make a decent fist of practically any surface/trail conditions.
WTB Resolute: Buy now from Tredz for £58
Tyre pressure
Checking your tyre pressure might be about the simplest mechanical task on a bicycle but it’s also one of the most important. We simply can’t talk tyre choices without also talking PSI.
Here’s why...
Tyre pressure (PSI/Bar) affects grip, comfort and rolling speed, and all of these are intrinsically linked. In our experience almost all riders run too much pressure.
A tyre has to deform to perform. It sounds like a cliché but it really is true. But there’s clearly a balance to be struck. Too low and a tyre will feel mushy and rob you of speed, and also runs the risk of sidewall damage plus air burping (if using tubeless) or pinch flats (if using inner tubes).
Too firm and a tyre will bounce over objects as opposed to flexing and conforming to surface changes which is the best way to achieve grip, plus it will feel much less comfortable.
For most riders there’s often a bit of a light bulb moment when the realisation comes that tyre pressure is hugely influential to a tyre’s performance, and especially that you can use much lower pressures than you might think, especially if you use tubeless tyres.
Checklist of expert tyre pressure tips
Correct tyre pressure is not a one time deal. Trail conditions, body weight, riding style, plus the weight of anything you plan to ride with (luggage etc) must all be taken into account.
Don’t just rely on the pump’s pressure gauge. These are often less accurate versus a dedicated tyre pressure gauge.
A separate digital gauge is often small enough to take in a pocket and makes it possible to experiment with tyre pressures on the trail. It’s best to start high and work down gradually.
Tubeless tyres facilitate lower pressures to be used without the risk of pinch flats and with reduced rolling resistance, while tubeless sealant will help to heal small holes and a tubeless repair kit should take care of the rest.
Rocky or very rough terrain generally requires more tyre pressure than soft terrain where the risk of impacts (and subsequent rim/tyre damage) is considerably less.
Narrower tyres generally require more pressure to avoid pinch flats, sidewall damage and potential rim damage.
Harder tyres do not make for faster-rolling tyres. Rolling resistance is a combination of many factors and in many cases a lower tyre pressure leads to improved performance overall versus an over-inflated tyre.
