If you want to know which gravel tire is best for your bike there are a few key numbers to make yourself aware of. The first is maximum tire clearance for your bike. Many manufacturers want to see 5-6mm of clearance between your tires and the bike frame. Knowing your bike’s measurements will allow you to maximize your tire size.
Once you have the clearance numbers figured out its time to think about how you will use the tires. Are you mixing gravel with pavement? Then tread pattern will be a key factor because it influences how your bike will perform on pavement too. If you plan to do a lot of climbing then tire weight will be a factor for consideration.
Size, tread pattern, weight, tubeless compatibility and more need to be considered when making a tire purchase.
What Size Gravel Tire is Best?
Most cyclists agree the preferred gravel tire size is in the 35-45mm size range. The 40-45mm portion being most popular. In fact, one of the most popular gravel tires on the market is the Maxxis Rambler and it only comes in the 38-45mm size range.
If you mix a lot of pavement in with your gravel rides then stay on the narrow end of the preferred size range. It will keep friction low allowing you to be faster on pavement. If your bike never touches pavement then wider will be better because you can carry more speed comfortably on the loose surface.
Because gravel is often times a rough ride, many cyclists prefer a wider tire. The additional air volume in the wider tires adds an element of suspension to smooth out your ride.
Many gravel riders have taken their road bike and stuffed the widest gravel tire they can fit, calling it a gravel bike. There is nothing wrong with going this route, especially if it saves you from having to buy another bike. I own two Trek Domane bikes. One has 40mm gravel tires stuffed on it (Read my Trek SL 6 Review Here) and the other has the original tires.
You may run into issues cramming wide tires onto your road bike. For example, a Trek Emonda owner might be disappointed with a maximum tire size of 28mm. If you want a proper gravel tire then having a proper gravel bike may be in order.
Does Tread Pattern Matter on a Gravel Tire?
Tread pattern on a gravel tire is something new to consider for most road cyclists. Road tires typically have a slick surface and tread is non-existent. With gravel biking tread pattern can definitely enhance your experience.
I ride gravel roughly 60-70% of my total mileage each week. For me, a tire with a closely concentrated tread pattern down the middle of the tire is important. It makes my ride feel smooth on pavement. Since up to 40% of my total miles will be on pavement that is a big deal to me. The aggressive knobby pattern on the edges of the tires still allow me to corner at high speeds when riding gravel.
Someone that rides exclusively on gravel may prefer a more aggressive tread pattern. If gravel is a minimum portion of your total miles each week then a less aggressive tread pattern will keep things feeling smooth and fast on paved surfaces.
Are Gravel Tires Good on Road?
Gravel tires will give you an extremely minor aerodynamic penalty due to their wider width. They will also have a higher rolling resistance. Those two differences are marginal at best. The differences will be more noticeable going from a 23mm road tire to a 45mm gravel tire than it will be going from a 32mm road tire to a 40mm gravel tire.
Gravel tires also come on a spectrum. That curve starts at a road tire and ends at a mountain tire. Every tread pattern in between is available. If you want a gravel tire that is good on the road then choose a tread pattern on that end of the spectrum.
The simple answer is, there is no simple answer. Yes, there are undoubtedly gravel tires out there that will perform with excellence on the road. They won’t be as good on gravel though. With gravel tires it is give and take. If you give up a little performance on the road, you take your experience off road to another level.
Are Gravel Tires Slow?
Tires alone don’t dictate speed on your bike. That being said, gravel tires will be slower than a road tire on smooth pavement. A gravel tire will be much faster than a road tire on loose surfaces. The answer to whether or not gravel tires are slow is complicated.
If you are concerned about keeping up on group rides when you leave your gravel tires on your road bike, don’t be. While gravel tires are not as fast, the difference is not so dramatic that you’ll start getting dropped on group rides. I would argue they may provide an advantage on extremely long rides. The added comfort of the wider tire makes long distance rides easy. I feel like I can ride longer, albeit at a slightly slower pace than with road tires.
Gravel tires will be slower in short sprints, but the second your ride takes you off pavement gravel tires gain a dramatic advantage. The loss of speed on pavement is nothing compared to the speed you gain on gravel surfaces. The additional surface area and knobby pattern of most gravel tires feel completely comfortable riding off road.
Which Gravel Tire is Fastest?
The fastest gravel tire will change depending on the terrain you are riding. For large chunky gravel a wider aggressive tread pattern gravel tire will be fastest. On hard pack a less aggressive and narrower tire will be fastest.
To choose the fastest gravel tire you have to match the tire to your terrain. Often times the tire that is fastest will change depending on where you are riding.
Tires are one of the few items I tend to buy online rather than going to my local bike shop. Rarely does my local shop have the exact size, tread pattern and brand of gravel tire I am looking for. Support your local bike shop when you can, but don’t feel guilty about ordering through Amazon or someone else when inventory is tight.