How to choose mountain bike tires

Understanding construction, tread design, compound and more

How To Tech Tires
Here's what to look for to find the tire you need.

Here’s what to look for to find the tire you need (click to enlarge).

Editor’s Note: This article is courtesy of the team at Art’s Cyclery. The original post can be found here.

When it comes to mountain bike tires, there are several factors to understand which will enable you to make an informed buying decision. These include construction, tread design, and compound. Here’s what you need to know about each one.

Construction

TPI (as in threads per inch) is the carcass or casing of a tire, and is made up of parallel threads, usually nylon, which are coated with rubber and oriented at a 45-degree angle from bead to bead. Higher densities of threads create a tire that is more supple with lower rolling resistance, but is less protected against punctures. Higher thread count tires, from 67 to 127 TPI, are used for cross-country and light trail riding.

Lower thread count carcasses use coarser threads with more rubber surrounding them. This makes for a stiffer, but more durable tire. These 50 to 67 TPI counts strike a good balance for heavier trail, all-mountain, and downhill tires.

Folding beads are made with a flexible material like nylon, Kevlar, or Aramid. Non-folding beads are made of steel and do not bend.

Folding beads are made with a flexible material like nylon, Kevlar, or Aramid. Non-folding beads are made of steel and do not bend (click to enlarge).

Bead

A tire’s bead is the inner edge of the tire. Air pressure within the tire keeps the bead seated properly in the rim, and the tire on the wheel. Beads do not appreciably stretch.

For our purposes, beads can be thought of as folding and non-folding. Folding beads are made with a flexible material like nylon, Kevlar, or Aramid. Non-folding beads are made of steel and do not bend. Folding beads are much lighter than steel beads.

Sidewall Layers

Sidewall construction influences a tire’s flat resistance, weight, and ride quality. Sidewall thickness is determined by how many layers of carcass, or plies, are wrapped around the tire bead, and by any inserts in between the plies. Inserts increase puncture protection, structural integrity, or both. Commonly used, lightweight, “breaker” layers are dense strips of nylon, Kevlar, or Aramid.

Sidewall thickness is determined by how many layers of carcass, or plies, are wrapped around the tire bead, and by any inserts in between the plies.

Sidewall thickness is determined by how many layers of carcass, or plies, are wrapped around the tire bead, and by any inserts in between the plies (click to enlarge).

These materials are light and pliable enough to minimally affect ride quality but still provide protection. Cross-country tires will have little to no sidewall protection to save as much weight as possible. Thicker nylon or butyl inserts are used in all-mountain and downhill tires for added pinch flat resistance and stability, at the expense of weight. Thicker tires with more sidewall structure can be used with lower pressure. Thinner, lighter tires rely on higher air pressure for structure and pinch flat resistance.

Width

Wider tires are heavier, but provide more traction and the ability to run lower pressure. Higher volume tires provide a bit of suspension also. For these reasons, tires from 2.25″ to 2.7″ and higher are mostly used on trail, all-mountain, and downhill bikes. Narrower tires are lighter, roll faster, and require higher air pressure. Tires from 1.9″ to 2.1″ are usually billed as cross-country or light trail tires.

Continue to page 2 for more on how to choose mountain bike tires »

About the author: Arts Cyclery

This article was originally published on the Art's Cyclery Blog. Art's Cyclery is dedicated to offering free expert advice, how-to videos, and in-depth product reviews on ArtsCyclery.com to help riders make an educated decision when selecting cycling gear.


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  • Timm says:

    Maxxis High Roller II or GTFO, GFY, IDGAF.

  • Reformed roadie says:

    @ Kyle Van Buuren: Ikon? Ardent Race? RR and RK are narrow lightweight XC tires. Are you really running either as a front tire?
    They’re faster until you a) flat or b) wipe out.

  • Mark says:

    I just started to know about bike and I am loving it. I’ve been to training classes at biketeacher.com just for me to know how to make my own bike. I also appreciated your blog this will also help beginners like me. Kudos!

  • matt says:

    Kyle- One popular tire? cmon man don’t make yourself sound ignorant. There’s plenty of good tires out there from plenty of companies. Ikon would be a great test against the tires you mentioned. I ride high roller 2 myself…

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