Older Tire Sizes
This section is provided primarily for reference. We are trying to carry a broad selection of tires to fit many different bikes, but many of these tires sizes are no longer available as new. You may therefore need to find someone carrying old stock in order to find some of these more obscure tire sizes. If you have an older bike that you're trying to fit with new tires, perhaps this information will help you find what you're looking for.
Bicycles have been around for over a century, so you can imagine the number of different tire sizes that have been produced. For many decades, each country that produced bicycles created their own tires sizes. Over the last twenty years, the industry has started to standardize the relatively few tire sizes mentioned above. Owners of older bicycles, though, have quite a challenge in finding the ride size tire to fit their steed.
Tire widths are specified as either a decimal number (e.g., 1.5") or a fractional measurement (e.g., 1 1/2"). Generally, tires that are specified with decimal widths are not compatible with tires specified in fractional widths.
The table below indicates some of the common tire sizes used over the past several decades.
ISO (ERTRO) Tire Sizes
In order to try and reduce some of the confusion with tire sizes, the International Organization for Standardization (ISO) developed a universal tire sizing system, known as the ETRTO system (after the European Tyre and Rim Technical Organization). This tire sizing system also uses two numbers, although they're reversed from traditional measurements. The first number refers to the tire or rim width in millimeters and the second refers to the diameter of the bead seat of the rim, also in millimeters. For example, a 700C x 23 tire would be specified as 23-622. The bead seat diameter of a 700C rim is 622mm.
Many older European manufactured tires and rims will have this ISO measurement printed on them, so it is helpful in determining what size tire you really need.
Refer to our Tire Size Chart for a list of standard ISO tire sizes used in the past few decades.
Note that just because two tires have the same rim bead seat diameter does not mean that they are compatible. Older bicycle tires used a straight-sided rim. As tire pressures increased, bike tires started to use a hooked rim so that the tire bead would be held more firmly.
