Spare tubes are a necessity when owning and riding a bike, as flat tires are a common occurrence in which you as a cyclist must accept as bicycle culture. Flat tires take place when the tube inside of a tire leaks air through a break in the seal usually caused by a puncture from a small sharp object or a tear due to improper installation. While getting flat tires may be inevitable, being prepared with spare tubes while on the road or trail, can save you a lot of trouble, some foot travel, and maybe even a phone call. Carry a few tubes with you while venturing the backwoods singletrack or cruising the bike path. Browse through our wide selection of tubes from Continental, Duro, Maxxis, Michelin, QBP, and many more.
When choosing the correct bike tube, the first thing you’ll need to know is your tire size or what size tire you plan on using. This can be as simple as locating the labeled size on your tire. If the labeled size is unavailable or unknown, it’s recommended you seek assistance from one of our experts via live chat or telephone, as there are many factors that can determine your tire size, such as: type of bike, rim width, wheel size (bead seat diameter), etc. Because of this, figuring out your tire size can cause the same kind of headache that only complicated algebraic equations cause. The good news is, by knowing your tire size, you can filter down your options and pin point what style of bike you likely ride
The following is a brief breakdown of common tire sizes:
As various countries began to manufacture bicycle parts, different systems of number markings were being implemented among these countries. This created situations where the same size tire could be labeled with two different numbers depending on the country, and different size tires were being marked with the same numbers. To eradicate this problem, the ISO (International Organization for Standardization) developed a universal tire sizing system to clear up the confusion. The ISO uses the width of the tire (in millimeters), and the diameter of the bead seat (B.S.D.) of the rim (in millimeters). The chart below is based on Sheldon Brown’s “Tire Sizing Systems” which shows the I.S.O. conversion of today’s common tire sizes.
|622 mm||29"||29"||700C||Road Bikes, hybrids, 29er Mountain Bikes|
|584 mm||27.5"||27.5"||650B||Popular wheel size among newer mountain bikes. This size is also making a resurgence among touring bikes.|
|630 mm||27" x anything||N/A||N/A||Old Road Bikes|
|571 mm||26 x 1, 1 1/8||N/A||650C||Triathlon, time trial, high performance road wheels for small riders|
|559 mm||N/A||26 x 1.00 - 2.3||N/A||Most mountain bikes up until the last 5 years. This size is quickly being replaced by 29" and 27.5" wheels. Fat Bike tires currently use this diameter with a 3+" width|
|590 mm||26 x 1 3/8 (E.A.3)||N/A||650A||English 3-sPEEDS. Department-store or youth 10 speeds|
|507 mm||N/A||24 x 1.5-24 x 2.125||N/A||Youth mountain bikes|
|40 6mm||N/A||20 x 1.5-20 x 2.125||N/A||Most BMX, trailers, recumbents|
|203 mm||12 1/2 x anything||N/A||N/A||Childrens bikes and scooters|
When shopping for bike tubes, the packaging is usually labeled as “bead seat diameter x rim width range”. For example, the Q-Tube mountain bike tube in Fig. 1 is labeled “26 x 1-1.25”. 26 refers to the bead seat diameter (also known as wheel size), while 1-1.25 is the range of tire widths this particular tube can accommodate.
*Note: When it comes to tire width, technically any tire/rim combo that has the same bead seat diameter can be used. However, this is not recommended, as using a narrow tire on a wide rim can result in pinch flats and rim damage, and a wide tire on a narrow rim can also result in rim malfunction and poor handling. Long story short, no rim is limited to just one tire width, but a range of tire widths that can be safely used with the rim’s width.
Once you know your wheel size, the next step is much simpler; know what kind of valve your wheels are compatible with (simply the size of hole drilled in the rim for valve). Luckily, there are only two types of valves that are commonly used today: Presta and Schrader. Presta valves have built-in valve caps, which must be opened before you can pump them up, and closed (retightened) after inflating the tire. Since Presta valves are light, don’t require a large hole in the rim and are easy to pump with a hand pump, they are used on almost all modern day performance bicycles.The wider Schrader (automotive style) valve is used on children’s bicycles and utility bicycles. The difference between the two valves can be seen in Fig 2.
Like everything else bicycle related, tubes come with various profiles and features for as many styles and disciplines of riding. Sealant filled tubes offer better puncture resistance and self-sealing should a puncture occur. Thorn resistant tubes use a certain kind of rubber compound such as butyl, or simply add more material to enhance the tube’s resistance to puncture by thorn. For “weight-weenie” cyclists (cough… “roadies”) or serious racers, there are tubes which are designed to be as Lightweight as possible. However, shaving weight off tubes usually compromises puncture resistance and makes the tube more prone to flatting.
To see how to properly install a tube, check out our Ask a Wrench episode on “How to Install Tubes” below.