Sometimes finding the right inner tube for your bike can be a challenge, but armed with a little knowledge you’ll be sure to get the right one. Today I’ll go over how to get the right valve, inner tube size, and inner tube material for your bike.
Valves: There are two main types of valves: Schrader and Presta. Wheels that use Schrader valves use the same length valve 99% of the time. That length is 32mm. It is so common that most Schrader valve tube packaging doesn’t even call out this dimension.
Presta valves on the other hand come in a wide variety of lengths. Common lengths are 32mm, 42mm, 48mm, 60mm, and 80mm. Just measure the valve of your old inner tube to find the right one for your bike. If for any reason you can’t find the length you already have, you can always use a Presta valve tube with a longer valve than you had before.
Tire/Tube Size: You should check the tire size printed on the side of the tire you are buying the tube for. The first number refers to the wheel diameter while the second number refers to the width. If there is an X between the first number and the second number, that is just an abbreviation for “by” and it can be ignored. But, if there is a letter other than X shown after either the diameter or width dimension, you will need your tube size to match that letter as well. For example, a 650x23C inner tube will not fit in a 650x23B or 650Bx23 tire.
Because inner tubes can stretch, they are rated for a range of tire widths. For example, a common road tire size like 700x23c can use an inner tube labeled 700×20-25c or 700×20/25c. If you have a mountain bike tire that measures 29×2.1, you can use a tube that is labeled 29×1.9-2.3 or 29×1.9/2.3. As long as your tire’s diameter matches the inner tube diameter and the width fits into the inner tube’s range, you have the right size tube.
Materials: Most inner tubes are made from butyl rubber and have a wall thickness of about 1.5mm. There are ultra light options that are about half as thick for riders that want to reduce their wheel’s rotational weight. Ultra light tubes give up a tiny amount of durability compared to standard thickness tubes, but the truth is, if a sharp object punctures a .75mm thick tube, it’s going to puncture a 1.5mm thick tube as well. The only way to gain puncture protection from an inner tube’s structure is to go with an extra thick thorn resistant tube. This type of inner tube is roughly 5mm thick under the tread and 2-3mm thick on the side that presses against the rim. The added thickness makes punctures far less likely, but all that extra butyl rubber weighs a lot.
Standard thickness inner tubes filled with sealant are another option for riders looking to avoid flat tires, but keep in mind that sealant filled tubes are designed to fix a puncture rather than prevent it like a thorn resistant tube does.
Now that you know which tube you need, be sure to buy a spare or two so that the next time you get a flat, you’ll be ready to fix it. Find the inner tubes you need at Art’s Cyclery.com