Bike Tires and Tubes 101


Bikewagon - BWCC

Tires are one of the most important parts of your bike, as they provide your contact for steering, stopping and accelerating. Good tires make life smooth and easy. Bad tires make for a bad day. Even the best tires wear out over time and need replacing, so whether your old set is falling apart or you are building a new bike, this guide will go over the different types of tires and tubes for different riding styles.

Sizing

Road bike tire

The main rule of tire and tube sizing is this: the tire must match the wheel, and the tube must match the tire. If you don’t know the size of your wheels, check your current tire. There should be a series of numbers on the sidewall, for example "700 x 20c" or "26 x 4.8." These designate the size of the tires.

There are two parts of tire size: width and diameter. Unfortunately, there are a bunch of tire standards. Some are measured in inches, some in millimeters. This can all be a bit confusing, but luckily more and more tires are marked with a standard: the ETRTO (European Tire and Rim Technical Organization) system, which consists of two numbers (for example, 20-622). The first number is the tire width, and the second number is the diameter of the bead (the part of the tire that seats into the rim to lock in place). If the second number matches on the tire and the wheel, it will almost always fit. In the ETRTO system, a 20-622 tire is equivalent to a standard 700 x 20c road tire.

The outer diameter of your tires is not so important for fit, but it does influence traction and speed. Skinny tires are faster and bumpier, while wide tires give softer rides.

It is important to note that if you choose a tire that is wider than your current model, you should make sure it clears your brakes and fork without rubbing. Frames made for skinny tires can rarely accommodate wider designs.

If you have any problems ascertaining the correct size of tire or tube, you can measure it directly or take it to your local bike shop for professional assistance.

Common Size ETRTO (ISO) Common Size ETRTO (ISO) Common Size ETRTO (ISO)
12 x 1-3/8 248 20 x 2.75 406 26 x 2.50 559
12-1/2 x 1.75 203 20 x 3.00 406 26 x 2.60 559
12-1/2 x 2-1/4 203 22 x 1-3/8 489 26 x 2.75 559
12 x 2.10 203 22 x 1-3/8 490 26 x 3.00 559
14 x 1-1/4 298 22 x 1-3/8 501 27 x 1.00 630
14 x 1-3/8 288 24 x 1-1/8 540 27 x 7/8 630
14 x 1-3/8 298 24 x 1-3/8 540 27 x 1-1/4 630
14 x 1 5/8 288 24 x 1.50 507 27 x 1.00 630
16 x 1-1/8 349 24 x 1.75 507 27 x 7/8 630
16 x 1-3/8 340 24 x 2.00 507 28 x 1-1/2 635
16 x 1-3/8 349 24 x 2.10 507 28 x 1 5/8 x 1-1/4 622
16 x 1.50 305 24 x 2.25 507 700 x28C 622
16 x 1.75 305 24 x 2.35 507 700 x 35C 622
16 x 2.00 305 24 x 2.50 507 700 x 25C 622
16 x 2.10 305 24 x 2.60 507 700 x 28C 622
16 x 2.125 305 24 x 2.75 507 28 x 1.20 622
16 x 2.50 305 24 x 3.00 507 700 x 38C 622
17 x 1-1/4 369 26 x 3/4 571 700 x 40C 622
18 x 1-1/8 355 650 x 23C 571 28 x 1.60 622
18 x 1-3/8 390 26 x 1-1/2 x 1-3/8 584 28 x 1.625 622
18 x 1-3/8 400 26 x 1-1/2 x 1 5/8 584 28 x 1.75 622
18 x 1.50 355 26 x 1-1/4 590 28 x 2.00 622
18 x 1.75 355 26 x 1-1/4 597 28 x 2.35 622
20 x 1-1/4 406 26 x 1-1/4 559 28 x 3/4 622
20 x 1-1/8 406 26 x 1 3/4 571 700 x 20C 622
20 x 1-1/8 451 26 x 1-3/8 590 28 x 7/8 622
20 x 1-3/8 406 26 x 1 5/8 590 700 x 23C 622
20 x 1-3/8 438 26 x 1.00 559 29 x 1.9 622
20 x 1-3/8 451 26 x 1.10 559 29 x 2.0 622
20 x 1.35 406 26 x 1.35 559 29 x 2.1 622
20 x 1.50 406 26 x 1.40 559 29 x 2.2 622
20 x 1.75 406 26 x 1.50 559 29 x 2.25 622
20 x 2.00 406 26 x 1.75 559 29 x 2.3 622
20 x 2.10 406 26 x 2.00 559 29 x 2.35 622
20 x 2.125 406 26 x 2.10 559 29 x 2.4 622
20 x 2.35 406 26 x 2.25 559 29 x 2.5 622
20 x 2.50 406 26 x 2.35 559 29 x 3.00 622
20 x 2.60 406      

Materials

Tire with Kevlar bead

Most tires are made of synthetic rubber which is formulated for maximum traction, but some tires incorporate other materials. In an effort to achieve maximum traction for cornering, some tires use extra grippy (though less durable) rubber compounds on the sides of tire.

Other tires use layers of Kevlar, ceramics, and other compounds to provide puncture and compression-flat resistance. These models are very effective at reducing the incidence of flat tires and are ideal for the more serious rider, commuter, or racer.

Additionally, you'll see tires with either wire (or steel) beads or folding Kevlar beads. Once it's on your bike it doesn't matter, but off the bike, a wire bead holds its shape and take up more space, while a Kevlar bead enables you to fold the tire up into a nice little package. Kevlar beads are usually a little bit lighter, and they may be a little easier to work with when repairing a flat, but they are usually a little more expensive.

Tread

knobby-mtb-tire

The most obvious thing you will notice about a tire is the tread -- is it knobby and fat like a mountain bike tire, or skinny and slick like a road bike tire? If you are going to ride on trails or gravel, or anticipate snow and other bad conditions, go for knobby tires with extra traction. If you want maximum speed, go for a thin, slick tire. If most of your riding is on rough roads or other "in between" terrain, look for tires that are medium in width and with moderate tread, like those mounted on many commuter and touring cycles.

Tubeless Tires

Tubeless tires -- like the name implies -- use no inner tube, but rather an airtight seam with the wheel, to maintain air pressure. These are most often used by mountain bikers who want to run very low tire pressures (for better traction) and avoid pinch flats.

Tubeless tires require special wheels (the rims will usually say whether they are designed for tubeless or not), and they are often a bit more expensive than traditional designs.

Tubes

Schrader and Presta Tubes

Like tires, tubes come in a variety of sizes to fit your wheels. Make sure any tubes that you purchase match the size of your wheels.

Different tubes also have different air valves. Most modern tubes for bike wheels use Presta valves, but some wider tubes made for mountain biking use Schrader valves. Make sure your pump is compatible with the tubes you use.

Pressure

Also marked on the side of your tire will be the minimum and maximum air pressure that should be used. Most mountain bike tires use relatively low tire pressures, well below 100 PSI. This makes riding on rough terrain more comfortable. Road bike tires generally use higher pressure, 100 PSI or more. This minimizes rolling resistance.

Whichever type of tire you use, the lower end of scale will deliver a more comfortable ride, while higher pressures make for more efficient rides and better flat resistance.

Pricing

Tire price is determined largely by build quality. More expensive tires tend to feature lightweight, durable materials that offer extra flat-resistance or other features like tubeless design. Tubes are the same, and it's usually a better idea to spend that extra dollar or two to get high quality inner tubes for your repair kit. Budget tubes may have manufacturing defects or weak valves, and a second flat tire a few minutes after replacing the first can really ruin your ride.

Tubes generally range in price from $5-10, while tires start as low as $10 for basic models and range as high as $150 or more for high-end designs featuring the latest technologies for efficiency and flat resistance.