A beginner's guide to mountain bike tires.

How often do you change your tires? Do you save it for when they are worn out, or does the change of seasons demand a rubber compound? Maybe you’re traveling somewhere new, and the terrain dictates what you wrap your wheels in. There are infinite tread patterns out there and just as many compounds, so what is the perfect balance for what/where you ride? As someone who has obsessed over the alchemy of tire choice for years, I hope I can help with some baseline information to help you on your tire journey.

Hopefully, this can clear things up for those of you who are trying to decipher the hieroglyphics printed on the sidewalls. Let's dive into casing, compounds, and pressure.

Casing

Heavier = More support/more durable

Lighter = Better ride feel/faster/less durable

What is a tire’s casing?

The tire casing is what holds the system together. It is the sandwich of materials that the compounds and the tread are adhered to and directly correlates to the durability and suppleness of the tire on the trail. The lighter the casing, the more supple and delicate the tire will be, but a heavier casing will mean greater sidewall support and puncture protection.

What casing should I be looking for?

With so many options on the market, it can be a little overwhelming trying to select the casing that works best for you, but the riding you do should offer a starting point. A heavier casing will offer more puncture protection and cornering support, but they are not quite as supple on the trail, will weigh more, and might be harder to install. Whereas a lighter casing will feel more spry on the trail, but will not be as resilient when faced with abrasion and punctures. Casing, again, should be dictated by a rider's proclivities.

One combination that works (for me, at least) is a medium or lightweight casing paired with some type of tire insert to bolster the entire system. This gives me the supple, light casing feeling on the trail while still getting support in corners and protection through rough chunks. This combo is certainly not for everyone, as I am fairly enigmatic and can count the number of flats I have had on the trail with one hand.

Just like with all things, balance is key, and the casing is often determined by where and what you ride, so I always suggest you check with the local shops and riders to see what they recommend for your area if you are unsure.

Compound

Softer = Grippier/Slower Rolling

Harder = Durable/Faster Rolling

What is a tire’s compound?

Tire compound refers to the density of the rubber used to construct the tire. Most tires will use a dual or a triple compound construction to offer harder knobs in the center and softer knobs on the side to provide better cornering grip and faster rolling speed. Typically a softer compound will wear out faster but offer better traction, whereas a harder compound lasts significantly longer but does not provide quite as much grip.

What compound should I be looking for?

This could be its own series of novels, and a quick few paragraphs will barely scratch the surface. If tire tread choice is the Lord of the Rings trilogy, think of tire compounds and casings as the Silmarillion. Every brand has its own way of talking about rubber composition, and each is unique. One thing that is true for all these brands is that softness generally correlates to longevity and grip. A soft tire compound will wear out quicker, but provide better grip on consistent surfaces, while a harder tire compound will last longer, roll faster, and will not grip a surface quite as well as a softer rubber.

It is ultimately up to the rider which compounds they want to go with, and the majority of manufacturers will usually offer each tread pattern in various compounds and, oftentimes, a compound blend that strikes a balance between soft, medium, and firm depending on what is demanded of the lugs. Softer shoulder knobs for the corners and harder, dual-density center lugs allow for a best-of-both tire. However, if a rider is seeking a balance of longevity and grip, a softer compound for a front tire and a harder compound in the rear is not uncommon.

Tread

Big knobs & wide spacing = Big grip, better mud shedding and cornering

Short knobs & tight spacing = Big Speed, less cornering ability

This is a divisive one, and I don’t want to claim that I know best or always make the right choices. I have brought a knife to a gunfight plenty of times. There are a plethora of options when it comes to choosing tread patterns, and what fits one style of riding won’t fit another. Depending on the “what and where,” the tread should be dictated by these factors. Again, if you are unsure, checking in at a local shop is the best way to gain some insight. Check our Shop Local series for recommendations on shops across the country.

There are plenty of top dogs we all see at trailheads across the globe from Maxxis, Continental, Schwalbe, and WTB, to name a few. Maxxis has done a fantastic job developing a pattern that is frequently imitated with its Assegai and Minion tires, and almost every brand offers something similar, albeit with different compounds and a slightly tweaked profile.. This imitation is definitely flattery, as a majority of the copycats are also high-performing, even without the employment of the delicious recipe Maxxis uses for their rubber compounds.

Tread consideration is also dictated by the conditions, which for most riders is determined by seasonality. Swapping tires frequently can really start to run a high bill unless you have support from a brand or you’re on a race schedule, in which swapping tires for changing conditions is smart. A lot of riders will make money stretch by keeping two sets in rotation - one for drier conditions and one for the wet. This, of course, depends on how frequently you ride.

Generally, again, it’s a good idea to run a grippier tread, with bigger knobs up front, and then a faster-rolling option, with smaller knobs out back.

Pressures

If you care about your tire performance, you should be using a reliable tire pressure gauge. Affordable tire pressure gauges are notoriously inaccurate. However, that’s fine, as long as they are precise - accuracy is the measure of how close to an absolute number your values are, whereas precision is how consistent those values are. So if your tire pressure gauge is always reading 3PSI low, that’s not a big deal, as long as you know what numbers it needs to spit out for your tires to feel good on your trails.

Unfortunately, this is one of the most overlooked factors when it comes to bike setup. Running the correct pressure for your riding style and terrain is essential to feeling confident on the bike. Running too much pressure in the tires can make everything feel rough and undamped. Tires are the first line of deformation when the bike hits the trail, and if the tires aren’t doing what they are designed for, neither is the rest of the bike.

Not enough pressure = striking rim, poor cornering support, and slow rolling.

Too much pressure = Poor ride feel, more chatter, and poor handling.

Just right = Cornering support, vibration dampening, solid contact patch

A balance of pressures is necessary for most riders, and it is rare to see the same pressure front and rear. PSI can and should vary depending on trail conditions and riding style, just like compound and tread patterns. One thing I see frequently is riders running too much pressure rather than too little, which makes sense. Who wants to pinch flat or bang rim when you can crank 30 psi into a tire and not worry about it? Likely, most riders are running too high of pressure, and the majority could benefit from dropping a few pounds.

Depending on the size of the tire your wheels are wrapped in and the casing they are constructed with, tire pressure should be the first thing on your mind when rolling out to the trailhead. I suggest everyone monitor and experiment with tire pressure, find that sweet spot, and stick with it.

Local anecdotes

I spoke with several riders at a local race series here in Boise, and the data showed that tires have a 6-8 month life cycle, with a few outliers only getting a year or more out of their rubber. Of course, this is regional data, and the terrain here in Boise, Idaho, is on the rockier and drier side of the spectrum. I did note that there was no correlation between tire choice and lifespan, but I will be diving deeper into this data to extrapolate further. My hypothesis on tread choice was correct, and the majority of riders were on Maxxis Minion rear and Maxxis Assegai front. However, the second highest number of riders were running the Continental Kryptotal, which I have been seeing more frequently this summer.

Most tires seen on the trail were either a DH or enduro casing, with only two or three riders opting for a trail casing tire. Those select riders on trail casings assured me that if they had a more robust casing to put on, they would have done so, but they either did not have time to swap, or they did not have

As for pressures, the majority knew their pressure within 5 psi, and I saw ranges from 22-31 psi, with the median being 26 psi for the rear and 24 psi in the front. One thing I noticed and found interesting was the riders who chose to run inserts were not running pressures drastically lower than those without inserts and the addition of inserts was typically for peace of mind.

Related: Schwalbe Announces new Albert and Shredda Tires with Radial Construction