How to Pick the Right Size Inner Tube for a Bike

How to Pick the Right Size Inner Tube for a Bike
Picking the right sized inner tube can be as easy as checking the sidewall of your tire. The size of the tire will be stamped somewhere on the sidewall, most likely on the right just above the inflation valve; this will also be the size of your inner tube. On the other hand, assuming that you have neither tire nor inner tube but a perfectly good wheel in need of both, you'll need to break out your measuring tape and take a few careful measurements.


Difficulty: Easy

Things You’ll Need:
  • Measuring tape
Step 1
Measure the inner rim width--the width of the rim between the two flanges. Flanges are the upper shelves running along the diameter of both sides of the interior of the rim. Record your figures in both metric and standard. To the confusion of many cyclists, tire and inner tube sizes can be listed by either system.
Step 2
Measure the bead seat diameter (BSD). The bead seat is the portion of the rim on which the tire bead sits. It's a second shelf on the inside of the rim, just below the flange. Place the tip of your tape on the outside of the rim at the height of the bead seat. Measure to the bead seat directly opposite.
Step 3
Write down your two numbers. Tires and inner tubes are listed first by BSD and then by inner rim width. For instance, a wheel with a BSD of 700mm and an inner rim width of 23mm will be listed as 700 X 23. This wheel would require an inner tube of the same dimensions.

Article Written By Matthew Ferguson

Matthew Ferguson is a writer living in Savannah, Ga. He has been writing for over 10 years and his work has appeared on various online publications. A collection of his short stories was published in spring 2010. He is a graduate of Appalachian State University.

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