Your Guide to Mountain, Gravel and Road Tires
Tires: you can’t ride a bike without them and a bike rides much better when you’ve got the right ones. Bike tires are literally where the rubber meets the road (and dirt, and gravel) and can be the deciding factor in whether your ride is all-time or Type 3 fun. These often overlooked bike components deliver an incredible range of performance across wet, dry, muddy, sandy, and slippery conditions and come in a variety of widths, circumferences, rubber thicknesses and designs.
But what makes one tire better than another? And with so many tread patterns, rubber compounds, widths and diameters, how do you know which tires to choose?
Here’s a breakdown of bike tires, from the fastest rolling road race rubber to the most durable, rock-deflecting downhill mountain bike tire.
First, a primer on tires
Regardless of whether you’re rolling on skinny 700x26c slicks or beefy 27.5”x2.6” trail chargers, all tires have the same essential components.
Tire Bead
The bead is the part of the tire that makes direct contact with the rim of your wheel. There are two kinds of beads: foldable and rigid. Foldable beads use flexible synthetic materials like aramid or Kevlar, are lightweight and come in at a higher price point. Rigid beads have a steel wire and are often lower in cost but are heavier. These are often seen on downhill tires to prevent burping and flats.
Tire Casing and TPI
The tire casing is the main make-up and structure of a tire. It’s generally composed of one or more layers of a woven material (referred to as ‘plys’) measured in threads-per-inch or TPI. These plys are covered in rubber to give the tire its ability to stay inflated and resist punctures.
Lower TPI (60tpi) tires feature a larger gauge thread that provides good puncture protection because of its thickness, but will roll more slowly.
Higher TPI (>120tpi) tires feature higher thread counts, making a more flexible and supple tire that can smoothly roll over roots and rocks. Higher TPI tires generally have good rolling resistance but often with reduced puncture protection.
Sub Tread (Puncture Protection)
Some tire manufacturers also offer a sub tread that is designed to give added protection (Maxxis examples - Snakeskin, Exo, Exo+, doubledown). This added protection can give you a piece of mind, but can slow the rolling speed. It’s a balance between ride quality and protection.
Tire Compound
Tire compounds have a significant impact on handling. Harder rubber formulas can have greater resistance to wear, but can also reduce traction. Softer compounds maximize traction but are prone to faster wear. Most companies are using a blend of compounds throughout their tires to get the performance they want.
For instance, Maxxis rates their tires as such:
Soft - Maxxgrip
Medium - Maxxterra
Hard - Maxxspeed
Tubeless versus clincher
Thanks to the advent of tubeless systems and sealant, tubeless tires are becoming mainstream on mountain bikes, gravel bikes and increasingly road bikes. Tubeless tires have a reinforced bead to help them ‘seat’ on the rim. Sealant helps to secure that seat, and fills in small punctures or tears in the tire that you may incur during the course of a ride. You can run tubeless tires at a lower tire pressure because there’s a decreased probability of pinch flats common in tube systems. This actually helps with tire performance on mountain bikes because the lower tire pressure translates to better grip and cornering.
Traditional clincher systems are still available and rely on the standard tube/tire combo. Clincher tires need to be run at a higher PSI to reduce the chance of pinch flats, but are easier to change in the field than a tubeless tire that gets unseated or has too large of a puncture for the sealant to fill.
Tire diameter and width
Before you choose a tire, you’ll need to know the diameter of your wheels. Mountain bike wheels are 26”, 27.5” or 29”, gravel and road bike wheels are 700c (though some gravel bikes will run a 27.5” (or 650b) knobby mountain bike tire).
Mountain bike tires range from 1.8” to around 2.6”, with “plus” 27.5+ tires ranging 2.8” to 3.0”, and fat bike tires up to 5” wide. How wide a tire you can run depends on the width of your rim and the tire clearance allowed by the frame. Not sure what your setup allows? Bring your bike into BBS to find out.
Gravel bikes on 700c wheels can range from 32mm to 45mm, also dependent on rim width and frame clearance.
Road bike tire widths range from the classic 25c to the modern 32c. Road tires traditionally ran narrower, but thanks to the adoption of tubeless setups, road tires are more commonly 28c, 30c, and 32c.
Across the board, wider tires have better grip and stability, but a narrower tire will roll faster and require more attention in fast cornering or slick conditions. Wider tires often weigh more, though this depends on the construction.
Tread pattern 101
Most bike tires have tread patterns designed to excel in certain kinds of conditions. How well each tire performs is somewhat dependent on air pressure but in general, here’s what to expect from different tread patterns.
Tight knobs and uniform tread
These tires are good for loose terrain and XC riding, are lightweight, and have low rolling resistance, meaning they roll faster. They might not grip as well when braking or cornering but are ideal for less technical conditions or if you want to save weight.
Taller knobs with bigger channels in between
Great for mud or trail riding, added traction on steeper, technical terrain, better grip for braking but have added rolling resistance. They are also typically heavier because of the casing (more durable and less flexible so you corner and hit things more aggressively).
Fast XC Tires - Short knobs in the middle with slightly bigger knobs on the sides for cornering. Tighter packed knobs are better for hard-packed and loose conditions because there are more knobs biting into the ground at once so you don’t slide as much. Knobs are uniform. If you’re shopping for Maxxis tires, this includes the Ikon, Aspen, Rekon Race.
Trail and Enduro Tires - Tall knobs, less uniform patterns, and wider channels. The knobs are typically not uniform like they would be on an XC tire and will instead be larger and more rectangular for better grip. There is a range between a DH style tire and an enduro tire. An enduro tire might have more intermediate knobs as you get to the outside of the tire and possibly smaller knobs in the center to roll faster because you still have to climb. For Maxxis tires, these include Rekon, Ardent, Dissector on the XC/trail end and Assegai, Minion DHF, Minion DHR II, Aggressor on the downhill/enduro end.
Gravel tires - The same principles apply to gravel tires as mountain bike. The tires that look more like a road tire will be intended for faster rolling and less traction. The tires that have more aggressive knobs will handle chunky gravel and singletrack. Fast gravel tires include Maxxis Rambler, Refuse, and Panaracer Gravel King. Grippier tires include the Terravail Cannonball.
Road tires - Road rubber is either slick or has shallow tread. Slick tires have the best traction when riding on pavement alone because they have the greatest surface area contact with the road. Some tires, like the fan-favorite Continental Grand Prix 5000, use shallow interspersed grip on the sidewalls for cornering.
The exceptional variety of tires available for all disciplines means that there’s something for every riding style, but it can also make tires harder to choose. Reach out to us if you aren’t sure which direction to go. Our expert staff will make sure you have the most suitable rubber for every endeavor.