Oversimplified: Tire Shopping Explained

February 10, 2014

No matter what kind of bike you ride or where, your tires affect your commute. So why is something so essential so often misunderstood? Size, PSI, TPI, weight, price... the variables can be confusing.

If this sounds like meaningless jargon fear not, we've oversimplified the process. Read on for our recommendations to make tire shopping easy.

To start, different types of bikes have different sized tires. To find your tire size, grab your best monocle and embrace the floor. Your tire size will be listed on the sidewall, but can be hard to spot. What you're looking for are two numbers separated by an "x". Something like 700c x 25mm, or 27" x 1 1/4". That tells you the tire diameter tire width

Your diameter is fixed, but you have lots of options for width so lets start there.

 

Tire width affects ride. As tire width increases (say from 23mm to 28mm), the maximum allowable pressure decreases (say 110PSI to 85PSI). That means thinner tires are often more firm, reducing rolling resistance and conserving energy as you ride. Big squishy tires don't immediately equal comfort. Bouncing around, rather than moving forward, isn't comfortable or efficient. We like 23mm - 28mm.

 

As anyone who has gone a few weeks without pumping up can tell you, tire pressure - measured in pounds per square inch (PSI) - makes a big difference. For 700c tires we think the sweet spot is between 100PSI - 120PSI. In that range the tire is firm and fast, but not so hard it's jarring and uncomfortable.

 

Be prepared to pay anywhere from $20 - $60 per tire. As you'd expect, the higher the price the higher the quality. Anything below $20 will likely have a short life and isn't worth the hassle. Alternatively, while there are plenty of tires above $60, they're usually over designed for commuting. Save your money, $30 - $50 will do you just fine.

 

Contrary to popular belief, tires are not constructed of rubber. They're made of nylon covered in rubber. That inner nylon casing has a thread count - threads per inch (TPI) - that has a large impact on the tires performance and durability.

A low thread count tire (say < 80TPI) has larger threads and more rubber. This makes the tire heavier, and a little more sluggish to ride, but it also means it has better puncture protection and a longer life.

A high thread count tire (say > 100) has finer threads and less rubber. This makes the tire lighter and more flexible so it grips the road better - we say it "performs" better - but it's also more susceptible to flats. And because the threads are a bit more delicate, the tire will wear out sooner.

60TPI - 160TPI covers a broad range of tires, giving you access to the benefits of each casing type.

 

While tire weight is a small part of your overall bike weight, it can make a difference. 200 - 300 grams per tire is our recommended range for city riding. Ultra light tires exist but sacrifice durability, while over built tires add unneeded weight.

Say you're comparing two tires of similar price, 100 grams different in weight. 100g might not seem like much, but that's 200g across both wheels which is about 1/2 pound. It's not huge, but every little bit counts. 

Go Forth And Shop

Your bike or your riding may not accommodate every recommendation above, and that's okay. Armed with this knowledge you can make an informed decision at your local bike shop to get the best tires for you.