Bike Wheel Size Measurement

What width is best when choosing bike rims.

Bike wheel size measurement. Your height is used to match bike frame size along with inseam size. Your wheel axle height sets your bottom bracket height. Multiply the length by two in order to calculate the tire s diameter. Step by step procedure of measuring tire size.

Although bicycle tires are available in vastly different sizes a majority have their diameter falling between 12 26. Measure the distance in inches from the ground beneath the tire to the center point of the wheel. For the width the size is between 1 75 2 215 inches. 27 5 650b wheels iso 584 mm one thing that makes bicycle wheel sizes notoriously confusing is the use of different names for the same size.

Of course this measurement is up to each brand s interpretation ridley s size s frames have a top. Simply stand up straight against a wall shoes off legs together shoulders back whilst somebody marks with a pencil the top of your head. City bike leg inseam cm x 0 685 your frame size mountain bike leg inseam cm x 0 66 your frame size road bike leg inseam cm x 0 70 your frame size if your leg inseam is 76cm then your right mountain bike size is 50 cm 20 road bike 53cm and city bike 52cm. If we then look at the 29 wheel its axle will be 1 5 higher.

The range of tire diameter is 12 to 26 inch and the width diameter is from 1 75 to 2 215 inch. The longer number of the tire is in diameter about an inch and the smaller number is the tire width in an inch. If we take the 26 wheel as the base height the axle height for a 27 5 wheel will be 0 75 higher. The actual iso diameter of a traditional 26 wheel is 559 millimeters.

Rims come in different widths with narrower rims 17 20mm more commonly found on lightweight cross country wheels and wider 20mm plus found on trail enduro and downhill wheels. Bicycle tires have two components. It s important to note that bike size measurements that use the iso system are in millimeters. Even worse the same or very similar markings can sometimes be found on completely different sizes of tyre.

It might be supposed that these two tyres are both notionally 26 diameter and one and a half inches in width but 26 1 is a whole inch bigger than 26 1 5. That s a system used for some road bikes too. This measurement is the wheel s radius or half of its diameter. Merida s road bikes go through s s m m l and l.

Bike frames are measured from the middle of their bottom bracket to the end of their seat tube.