Two tyres with the same ISO markings are completely interchangeable, even if one seems to be metric and the other is also marked in inches. For example, 650B and 26×1½ are both 38-584 and should be marked accordingly. Look for the ISO numbers and you always know exactly where you are. Metric internal thread dimensions chart according to ASME B1.13M "Metric Screw Threads: M Profile" standard. Minor diameter, pitch diameter and major diameter

One way to define it, popular in times past, was to measure the tyre’s outside diameter and its maximum width when inflated, but this can be misleading. For example, some tyres marked 28" are actually much less than 27 inches in diameter, while 26×1.5 and 26×1½ are two completely different sizes. Cary, Palmdale, Hayward, Salinas, Frisco, Springfield, Pasadena, Macon, Alexandria, Pomona, Lakewood, Sunnyvale, Escondido, Kansas City, Hollywood, as shown in the image to the right. Note that the denominator of a fraction cannot be 0, as it would make the fraction undefined. Fractions can undergo many different operations, some of which are mentioned below. How do you know what size tyres will fit your bike? It should be easy: buy exactly the same model of tyre as those already on the bike. Of course, this isn’t much help if identical tyres aren’t readily available, if you fancy something different or if you’re looking for replacements in unusual and hard-to-find sizes. The former is ‘fractional’, the latter ‘decimal’, and as a rule decimal and fractional tyre sizes that look the same are not.Tyres suitable for use with dedicated tubeless rims, or with a conversion system which employs tape to seal the rim bed, are marked using a sidewall decal such as tubeless-compatible, tubeless-ready, tubeless-easy or similar. They have a special stretch-resistant folding bead made, usually, of carbon fibre. The ideal relationship between tyre and rim section is about 1.8 to 1, but any tyre from 1.4 to 2.2 times should fit – always provided that the bead diameters correspond. Nowadays almost all rims have hooked flanges (required to retain folding tyres) that will hang onto tyres up to three times their width. This increases the cushioning effect: you get more comfort out of the same tyre at the same pressure when you fit it to a narrow rim – yet it still rolls just as easily. the decimal would then be 0.05, and so on. Beyond this, converting fractions into decimals requires the operation of long division.

The gorgeous Sigma 1.2 isn't better because it blows more, it's miles ahead because it simply has beautiful character add any focal point, at every aperture, in any light and for any subject. The initial two-digit number is the tyre section and roughly indicates the tyre width. Its actual width is normally less, but varies according to how the tyre is designed and the width of rim to which it is fitted. But the height of the tyre usually corresponds quite closely to tyre section, so overall diameter approximately equals the bead diameter plus twice the section. The three-digit number after the dash is the more important. This is the bead diameter at which the tyre fits onto the rim.There is no industry-wide convention for tubeless tyre fitment and satisfactory results are mostly likely using parts made for use together such as Mavic’s UTS (Universal Tubeless System) tyres and rims. Nevertheless, tubeless-compatible tyres are generally available in the standard 29"/700C/622mmISO, 27.5"/650B/585mmISO and 26"/559mmISO formats. It is inadvisable to use non-tubeless tyres without an inner tube as there is a risk of tyre blow-off. Tubular tyres This process can be used for any number of fractions. Just multiply the numerators and denominators of each fraction in the problem by the product of the denominators of all the other fractions (not including its own respective denominator) in the problem. EX: Product images by Dan Bracaglia, all other photographs by Rishi Sanyal unless otherwise noted. Key specifications: Henderson, Greensboro, Plano, Newark, Toledo, Lincoln, Orlando, Chula Vista, Jersey City, Chandler, Fort Wayne, Buffalo, Durham, St. Petersburg, Irvine,

That’s how the diameter and circumference (circ – equals distance rolled in one turn of the wheel) are calculated in the Tyre size table. These figures are useful for setting your cycle-computer and precisely calculating gears. Manitoba, MB, Saskatchewan, SK, Alberta, AB, British Columbia, BC, Northwest Territories, NT, Nunavut, NU, Yukon, YT Some rims are also now marked according to ISO with their bead diameter and internal section (width where the tyre fits); 622-17 for the size usually fitted to touring and hybrid bikes, for instance. But some manufacturers give the overall width instead. Subtract 6mm from overall width to estimate the rim section, or simply measure the distance between the flanges. Norfolk Island , Northern Ireland , Norway , Oman , Pakistan , Palau , PW, Panama , Papua New Guinea , Paraguay , Peru , Philippines It is often easier to work with simplified fractions. As such, fraction solutions are commonly expressed in their simplified forms. 220Baton Rouge, Richmond, Boise, San Bernardino, Spokane, Birmingham, Modesto, Des Moines, Rochester, Tacoma, Fontana, Oxnard, Moreno Valley, Fayetteville, Placing the focusing optics at the rear of the lens allows optical designers to greatly reduce focus breathing. Note 1: Dimension is used in the design of tools, etc. In dimensioning internal threads it is not normally specified. Supplements: All tyres are marked with a pressure. Sometimes this is an absolute maximum that nobody should need to exceed, or sometimes only a recommended maximum that may be exceeded by heavier riders (such as tandemists). Another reason not to exceed the 2.2 limit on road is that a more bulbous tyre can deflect side ways with a noticeable effect on control and road holding. Conversely, fitting a tyre of less than 1.4 times the rim section will result in a harsh ride and more rolling drag than a larger tyre at the same pressure. Tubeless tyres