MTB Tire Knob Shapes

Mountain bike tires have all kinds of knob shapes in different sizes. Each knob shape and size gives you a certain kind of ride experience. Understanding how tire tread patterns work and the various types of knob shapes can help you match the right tread design to your riding style. In this short guide, I’ll describe 5 types of MTB tire knob shapes, 3 kinds of tread zones, spacing, siping, cuts, grooving, and more.

Types of MTB Tire Knobs and Sizes

The knobs of a mountain bike tire seat on a kind of a base layer, the casing. The casing itself is made of synthetic fibers, typically nylon. MTB tire makers layer these fibers in alternating directions. To boost a tire’s puncture protection ability as well as stiffness, manufacturers may add extra materials and layers before adding the tread.

Below are three kinds of MTB tire knobs you need to know before choosing your next replacement tire.

5 Types of MTB Tire Knob Shapes

  • Square-shaped knobs
  • Ramped knobs
  • Tapered knobs
  • Micro knobs
  • Darts and chevrons

Let’s now look at each of these knob shapes and sizes.

1.Square-shaped MTB Tire Knobs

square MTB knobs
square MTB tire knobs

These knobs are more or less square in shape/design. Or at least, they’re noticeably less round. Compared to knobs with a rounder shape, square knobs win out in the traction department.

They dig deeper into the surface and give your ride a solid, stable feel. But as you might already know, tire treads that offer greater grip almost always have more roll resistance. Put simply, more rolling resistance equals less speed.

Square-shaped knobs are good for riding over dirt trails and gravel. Y0u can also reliably use them for rolling over moderately rocky terrain.

2. Tapered MTB Tire Tread Pattern (for Wet, Muddy Conditions)

tapered MTB knobs
tapered knobs for wet, muddy conditions

Tapered knobs are larger at the bottom and get small toward the upper end. That is, they taper as the distance from the base increases.

Tapering MTB tires makes it harder for mud and dirt to clog up the tread. Actually, tires with this kind of treat self-clean as they roll on the ground. This is the kind of tread pattern you need for biking through soft, wet, muddy surfaces.

Tires with this knob design typically have a low knob count and there are enough spaces between them. This tread pattern clears mud really well, and when you’re rolling over firm terrain, they dig right in and provide good grip.

3. Ramped MTB Tire Tread Design (Great Braking & Rolling Efficiency)

Ramped tires are designed to have reduced roll friction and great braking power. To ramp a tire, manufacturers make one of the knob’s front angle slacker while making the back of the knob stand at a steeper angle. The rear of the knob looks almost vertical relative to the casing.

ramped mtb knobs
ramped MTB knobs

With this tread design, you’re going to have really nice rolling efficiency. And the moment you pull the brake levers, the knobs quickly bite into the riding surface, keeping you secure and safe out on the trails. This tread pattern lives on the cusp of relatively mild acceleration forces and massive braking forces.

4. Micro MTB Tire Knobs (for Gravel, XC, and Cyclocross)

As the name suggests, micro MTB knobs are pretty small compared to all the other tread types discussed in this guide. In addition, these knobs stand short and are quite compact.

The overall design makes for a relatively lighter tire, and that’s something most cyclists want. This reduced tire weight translates into enhanced rolling efficiency. Also, these small knobs tend to experience more uniform flex in relation to the casing.

small and micro mtb knobs
small and micro mtb knobs

But I should also mention that lots of MTB tires these days tend to deform when you’re cruising down the trail at a high speed. And when they deform, roll resistance increases and you got to pedal harder for the same amount of forward motion.

If you mostly bike on gravel surfaces or are a cyclocross or cross-country mountain biker, go with tires having this kind of knob design. But there’s one disadvantage with micro knobs. Small knobs provide reduced grip when you’re traversing loose trails.

5. Darts and Chevrons (Improve Front-wheel Turning Efficiency)

Darts and chevrons are cycle-speak for angular or pointy MTB knobs that are designed to offer relatively large, horizontal, forward edges. While the forward edge of the knob is pointy or angled, the rear edge is designed to give you a better braking ability.

darts and chevrons
darts and chevrons

But better braking isn’t the only thing you get from darts and chevrons. The horizontal edges offer additional edges that increase the turning efficiency of a tire. And because turning efficiency is where this tread design shines best, tires boasting these knobs are often used on the front wheel.

Does the Knob Spacing Pattern Matter?

Wider spacing between the knobs = better grip and less mud and loose dirt caking into the tread, good for downhill MTB tires

Narrower/Less spacing = less rolling resistance, good for cross-country tires

Yes, spacing matters, as does tread design. The kind of knobs you have on a MTB tire affect the ride experience in a noticeable way. But there’s more to it than just the shape and angling of these rubber features. The second most important aspect is how much spacing is there between the knobs.

A tighter tread design with little spacing between the knobs translates into a smoother forward roll thanks to the reduced roll resistance. That’s the kind of tread design spacing you want on a cross-country wheelset.

On the other hand, having large knobs with wider spacing enables the tire to dig deeper into the surface, increasing grip. This is the kind of tread design and spacing you see on the classic downhill MTB tire. The wider spacing also makes sure that the tire spits mud and loose dirt out so that they won’t lodge between the knobs and harden up.

3 Types of Bike Tread Zones

tread zones
Three types of tread zones

Bike tire makers don’t position knobs uniformly throughout the surface of the tire. Also, knobs aren’t always the same size even on the same wheel. Manufacturers organize the tread pattern around three zones namely:

  • Center tread zone
  • Transition tread zone
  • Side tread zone

Let’s take a look at each tread zone.

Center Tread Zone

The center tread zone is pretty much the workhorse on any kind of MTB tire. This is the largest of all three tread zones. Virtually the entire zone stays in contact with the riding surface. It’s where the majority of rider weight goes.

Since you’re rolling on the center zone nearly all of the time, it vastly determines the total amount of rolling friction a tire faces. Whenever you’re riding in a more or less straight trail with very little cornering, this is the zone you’re working with. This zone influences the wheel’s straight-line grip as well as the overall braking power you can expect from a wheel.

Some manufacturers opt to put smaller knobs spaced closely on the center zone to lower rolling drag. But they can’t do that without adversely affecting grip and braking ability. This knob placement works great as long as you’re cycling over mostly hard-packed trails and surfaces.

What if your trails are mostly covered with loose dirt? Go for a tire whose center zone features larger knobs with wider spacing.

Transition Tread Zone

Sitting on either side of the center zone are the transition zones. If you need to lean a bit some of the time because your singletrack features moderate turns, you’re going to need to rely on the transition zone.

If a tire manufacturer wants their tire set to provide more grip in the transition zone, they usually increase the number of knobs there. But remember, the more knobs in the transition zone, the more the roll friction.

Side Tread Zone

When you’re riding on trails with many twisty turns and berms, you’re going to need to use deeper lean angles. And that’s where the knobs on the side zone come into play.

Typically, the side tread zone knobs are larger than those on either the central zone or transition zones. The knobs are larger here so that you can have as much traction as you need when negotiating really tight corners.

That said, chances are that you’ll always use the side tread zone knobs of your tires less often than those on the other two zones. But because these side zone knobs are shaped to increase traction, there’s a bigger loss of roll efficiency there. The good thing is that you use this zone momentarily rather than constantly, which means that roll efficiency loss isn’t a major concern.

How Long Do Bike Tires Last?

Bike tires generally last anywhere between 1,000 miles and 3,000 miles. And, you should be able to squeeze at least 2,500 miles out of most top-end tires and of course less mileage from cheaper options. But in the end, bike tire durability depends on the nature of the trails you mostly ride on and your riding frequency. 

Siping, Cuts, Grooves, and Studs

Bike tire designers have other ways aside from treads to make tires behave in certain ways during use. Siping, cuts, grooves, and studs are all different approaches to giving tires a nuanced roll quality.

MTB tire knob sipes
MTB tire knob sipes

What’s siping on bike tires? Siping or sipes refers to small sawtoothed cuts made into tire lugs mostly to increase traction on wet, slidey roads. You want your tires to be siped if you do lots of road touring and riding on wet smooth asphalt. Siping tires gives them rugged, elongated edges, and these edges increase the tire’s multi-directional grip.

These sawtoothed edges open up when the tire flexes, and when that happens the water between the wheel and the ground gets ejected. What’s more, siping may compel the knobs to deform in desired ways, empowering the wheel to ride better when the cornering gets harder.

By the way, it’s possible to sipe your MTB tires if you need to, but those who do it often report marginal improvements in terms of traction.

Grooves are like wider sipes but without the tiny zigzag/sawtoothed edges. Some people use the terms grooving and siping interchangeably, but there’s a difference as you’ve seen. Grooving gives tire lugs additional edges, which translates into greater grip. A tire with cuts and grooves usually demonstrates better turning, braking capabilities and struggles less at acceleration.

Do you see the tiny holes in the tire lugs above? Metal studs can be sunk into these holes to increase a wheel’s ability to roll over icy, snowy surfaces. Many fat bikes have studded tire lugs for that very reason.

The Compound Matters, Too

Designers formulate all kinds of tire compounds, and each formula works a little differently than another. These creative folks pair up lug design with a specific compound to create a tire that performs in a certain way. A good rubber compound provides the kind of tire flex required so that the lugs can perform as desired. So, you should pay attention to all these considerations when shopping.

What’s a Pinch Flat?

A pinch flat happens when a mountain bike wheel hits a rock or root with a massive force, rupturing the inner tube. The compression from the hit object as well as from the rim focuses on the rubber tube, pinching it. The result is a pinch flat, also called a snakebite in mountain biking lingo. That’s because it looks like two tiny holes not different than those made by snakes when they sink their fangs into something.

This type of flat is the main reason many off-road riders today favor tubeless setups over the classic inflated-tube-inside-a-tire setup. In a tubeless setup, there’s no tube inside the tire. Instead, the tire bead locks into a special rim, and a substance called a sealant self-mends any tiny holes from the inside out.

What’s a Puncture Flat?

A puncture flat is what happens when a sharp object such as a nail or a thorn pricks through the tire and pierces the tube inside. Again, this is a common issue with tubed MTB tires. While tubeless tires may not eliminate flats entirely, they’ve been known to minimize them significantly.

Wrapping It Up

When it comes to MTB tires, there are at least 5 different kinds of tread designs. Each tread design demonstrates super performance in specific trail conditions. Be sure to choose a tread pattern that’ll work well for the trails you have.

The amount of spacing between tire lugs also matters, as does the tire compound and other special treatments such as sipes, grooves, cuts, and studs. Happy mountain biking!