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How to Choose Bike Tires

With so many options, how do you choose the right tires for your bike?  We’ve got you covered with this helpful article. We'll go over the most common questions customers ask us.

How to tell if you need to replace your bike tires

Here's some quick tips on when you start looking for replacement tires. Knowing you have a busted tire is one thing. Preventing flats before they happen in another. If you can identify these warning signs then you can replace a worn out tire before it ruins your next ride.

Here are some signs that will tell you a tire is ready to be replaced:

  • Worn-down tread, especially in the center
  • Missing or broken knobs
  • Aged and cracked rubber
  • Sidewall damage - abrasions, cuts, or 'sweating' sealant
  • Warped casing
  • Frequent flats
  • Poor handling

Finally, time is a killer of tires.  Keep track of how old your tires are.  Rubber will only keep for two to four years before becoming hard and brittle.  A tire may not have any visible signs of wear and still be bad if the rubber is too hard.  If your tires are more than five years old, get new ones!

How to choose the right bike tire size

Here are the main factors you need to consider when shopping for new bike tires. First it’s about knowing what will fit, then you can refine your search to pick out the models that will give you the performance you’re after.

Bike Tire Sizes (Traditional & ISO)

Before you start shopping, you need to know what tire size will fit your wheel and frame. Get the wrong size tire for your wheels and you won’t be going anywhere. 

The size is printed on the sidewall of the tire in two ways:  Traditional and ISO (International Standard for Organization).  The traditional method is usually in bold and easy to read.  Consider this Traditional measurement example:  29X2.50.  The first number (29) is an approximate measurement (in inches) of the outside diameter of the tire when inflated. The second number (2.50) is an approximate measurement (in inches) of the tire width when inflated. 

The Traditional method can lead to confusion at times with less common tire sizes.  Sometimes the size is listed as a decimal and other times as a fraction. These always represent different sizes...even if the printed numbers equal each other!  Confusing, huh?  That's why it's important to be familiar with the ISO measurement also printed on the tire (although often less noticeable).  

Using the above example, the ISO measurement would be printed as 63 - 622.  The first number (63) is the inflated width (in millimeters).  The second number represents the diameter of the bead seat of the rim (in mm).  This is an exact measurement and is important in determining if a tire will properly fit a rim. 

Road bikes throw in one more twist.  The Traditional size printed in bold on the sidewall is usually referring to a French method.  For example, a common size you may see is 700X25C.  Here, the first number is an approximate measurement (in mm) of the outside diameter of the inflated tire.  The second number is the inflated tire width (in mm).  The 'C' refers to the rim width.  In Utah, we usually only see 'C' labeled rims with a 622mm bead seat diameter.  However, rim widths range A through D with each letter representing a different width and bead seat diameter.

Below are some common tire sizes (with the ISO bead seat diameter listed in parentheses):

Mountain Bike Tires

  • 29 inch (622mm): Super fast with lots of rollover power and downhill control. Perfect for the majority of trail riders.
  • 27.5 inch (584mm): Agile and playful. Great for tight turns, creative lines, and getting air. Gives smaller riders the best performance. Sometimes referred to as 650b.
  • 26 inch (559mm): Less common these days, mostly found on older mountain bikes but also found on fat tire bikes.

Road, Gravel, and Commuter Tires

  • 700c (622mm): The most common size tire for road, gravel, and commuting. Great for the majority of riders. Tons of options.
  • 650B (584mm): A wider tire that’s more capable off-road. Great for gravel and anyone looking for more traction and comfort. Sometimes referred to as 27.5 inch.

What’s the difference between 27.5 inch and 650B tires?

This is another example of the French sizing method.  27.5 inch and 650B tires technically refer to the same size as both fit on the same diameter wheel (584mm).  

The term 27.5 inch is mostly used in the mountain biking world filling the gap between 29 inch and 26 inch. Tires designated as 27.5 inch are usually (but not always) mountain bike-focused with more tread for off-road riding.

The term 650B is more commonly used with gravel and touring bikes. They typically have less tread than mountain bike tires.  They're fast rolling on a variety of surfaces, but they offer more traction and comfort than standard 700C tires.  The outside tire diameter of 700C and 650B is very close.  This allows many gravel bikes to swap between the two wheel sizes.  700C is fast and efficient with a bigger rim and skinnier tire while 650B is smoother and more comfortable with a smaller rim and fatter tire.  

Common Bike Tire Widths

Once you know the size tire you need for your wheels, the next step is to choose the right tire width. Obviously a road rider will be looking for a skinnier tire than a mountain biker, but even small differences in width can make a big difference when it comes to how your bike performs.

Here are the most common bike tire widths:

Mountain Bike Tire Widths

(measured in inches)

  • 2.1 - 2.3” : Light and fast - great for XC racing/riding and flowy singletrack
  • 2.4 - 2.6” : Trail tires have amazing grip on loose and technical terrain but still roll fast
  • 2.8 - 3.0” : Also called 'plus' or 'mid-fat' - great for serious traction and increased comfort but slower rolling
  • 3.5 - 5.0” : Fat bike tires for maximum float and traction often used in snowy conditions

Gravel Bike Tire Widths

(measured in mm)

  • 38 - 45mm : Speed-focused, great for racing and fast-paced riding
  • 47 - 50mm + : Adventure-focused, great traction and comfort for bikepacking and wild rides

  • 1.9 - 2.3” : Some gravel bikes accept larger tires even as big as XC MTB tires - these are measured in inches

Road Bike Tire Widths

(measured in mm)

  • 23 - 28mm : Fast and light
  • 30 - 35mm : Endurance tires - not quite as fast, but improved traction and excellent comfort

Commuter Bike Tire Widths

(usually measured in mm)

  • 35 - 38mm: Faster-paced commuting for smoother surfaces and light gravel
  • 40 - 45mm+: More traction and comfort for gravel roads

Other factors to consider when shopping for tires

Rim Width

Just knowing the wheel diameter (29/27.5/etc) isn’t always enough. If you’re thinking of buying a new tire that’s narrower or wider than the one you’re replacing, you’ll also want to make sure the tire you’re shopping for is the right width for the rim.

If you know what rims you have, you can look up its internal width and check the tire manufacturer’s rim width compatibility. This can be a little confusing, and lots of riders don’t know exactly what rims they have. We’re happy to make sure you get the right tire for your wheels, so stop by or give us a call if you want some help!

Max Tire Clearance (frame clearance)

Another factor to consider when considering a tire that’s wider or narrower than the one you’re replacing is frame clearance. Because bikes are designed with specific purposes in mind, their frames and forks have limits on what tires will fit and what won’t.

You can usually look up the max tire clearance of your frame on the bike manufacturer’s site, but again, if you’d like the help of professionals you can stop by or give us a call!

Need to buy tubes or gear for tubeless setup?

Bike tire size FAQs

Tubes vs tubeless bike tires, which is better?

Tubeless bike tires can be used with tubeless compatible rims without inner tubes. Without tubes, you can run lower tire pressures without getting pinch flats (caused by the tube being squished). Lower pressure also offers more comfort and traction off road, so many mountain bikers and gravel riders choose to go tubeless. Tubeless conversion requires tubeless compatible tires and rims, tubeless rim tape, and almost always an air compressor. Because tubeless can be a pain to set up, most commuters and casual riders won’t bother.

How much air should I put in my bike tires?

Every tire has a recommended PSI range on the sidewall, and it’s best to stay within those limits so you don’t get flats or blowouts. You can adjust the air pressure within that range to suit your preference.

What bike tube valves do I need?

If your tube’s valve looks like what’s on your car, you need a Schrader valve. If it's a long and skinny valve with a twistable top, you need a Presta valve.

What is a good TPI for bike tires? What does TPI stand for?

Threads Per Inch. A higher TPI (120) is lighter and more performance oriented for riders who want speed benefits. A 60tpi tire is more durable but slightly heavier.

How much tread do I need for bike tires?

Thinner tires with less tread are faster on smooth surfaces, and wider tires with more tread are better from loose, challenging roads and trails.

Are there bike tires with puncture protection?

Yes, some tires come with reinforced material in the rubber casing that can help prevent punctures. Check the tire’s description to know for sure.