Bicycle Tube Size Conversion Chart

Mountain bike tubes range in size from 26 through to a 27 5 and 29.

Bicycle tube size conversion chart. Bicycle inner tube size conversion chart plus recommendations june 1 2020 by ben. The standard is called the iso 5775 and if your shop doesn t have the chart available it is published at the websites of the iso and the etrto. Checkout dimensional conversions tables sizes are expressed differently according to the various standards or uses. You must make sure you replace your inner tubes with a tube that is the right size according to the diameter and width for your tyre.

Mountain bike tyre sizes are usually stated in inches. Calculating spoke length to calculate spoke length you need to know the erd and several other dimensions for the rim the hub and the spokes. The second number 1 1 8 is the height of the tire in inches and fractions of an inch. 26 x 1 1 8 x 1 1 2 the first number 26 is the overall tire diameter.

Mtb tubes must be the correct width as well also measured in inches. Mtb and city tire sizes are given in inches. This is to allow the tube to expand to the correct size for your tires and can range from as narrow as an inch right up to a tire width of 2 5 or greater. The even simpler answer is to stick with the 700x38c sizing and buy a tube that s labeled with that size.

The sad fact is that inner tube sizing and tire sizing for that matter is a dark art. The simple answer is. Over time different countries and different manufacturers have built up a system that is so complex that probably only 2 or 3 people in the world actually understand it. We ll take a look at why thi.

Finding the right inner tube depends on the size of the tires on your bike. While you can find a variety of bikes with wheel sizes ranging from 16 to 27 5 inches the most common sizes include 26 inches 27 5 inches 29 inches and 700c. Etrto english size french size german size rim circumference mm find tires. Most road bike rims measure 26 or 27 inches across while the nipples measure about 12 to 16 mm making the erd of most road bikes somewhat less than 26 or 27 inches.

So a 29 inch mtb tube will have the same diameter as a 700c road wheel while a 27 5 inch tube will be the same diameter as a 650b road wheel. To convert tire tube sizes from one notation to another it is necessary to use the chart published by the iso available at any reputable bike shop.