"I'd definitely pose nude again. No qualms. I actually just had my breasts done again. Just updated, like new tires" - Jessica Hahn
Tires are certainly contenders for the most critical components to the performance of a bicycle. They provide suspension and traction that are critical to propelling and controlling the ride. Besides air drag (which tires greatly affect aerodynamics), ground resistance is the biggest factor that robs power from the rider.
Tires are manufactured in a plethora of tread styles, sizes, and rubber composites that are built for any purpose. Different methods to attach a tire to the rim exist, some using wired beads that clinch inside the rim, and others involve adhesives. The diameter of the tire must match the diameter of the rim, but the width of the tire varies within the limits set by the rim.
A tire consists of a few micro layers of rubber composites between the inner tube and the riding surface. They fit inside the rim using a bead, or a bulky trim to remain held inside the rim when the inner tube is pressurized. The tread is the tire bottom, built to contact the riding surface. The underlying layer and the sidewall are sometimes referred to as the casing.
Physics 101: Inflation affects many key factors of a tire. When slightly under inflated, the tire is saggy and soft. It grips the riding surface well, and acts as a nice fluffy cushion. If slightly overinflated, the tire makes less contact with the ground. This means less resistance (and therefore traction), but the rider can go faster with greater efficiency. Ambient air temperature, and changes in altitude at different locations have a huge barometric effects on the tire pressure. Hot tire = more inflated, cold tire = more deflated. React accordingly.
Brand-spanking new tires are sweet. Everybody loves that new tire smell, and the curiosity of those funny looking "sprues" makes everyone feel like a kid again.
Many low-end rubber composite mountain and road tires can be purchased for less than $20. Fresh tread is fresh tread. That being said, according to my research, cheap tires don't win championships.
For the rider of any cycle looking to up their game, there are many options. Tire material composition and tread pattern are factors that affect the pricing, as both affect time and difficulty of manufacturing.
Most tires fall under $250/tire on Amazon.com for both mountain and road bikes. The market is huge with any tread pattern and size imaginable.These tires are specially designed by world-class, competitive tire companies.
Even nicer tires are about $750, and if you just hit the jackpot, some new tires can be well over $1,500. Knock yourself out!
Whether you have a blowout or are just over trusting your life in those bald, kinda round things, replacing a tire is easy business. It requires almost no special tools, and can be done in about 15 minutes.
From the beginning of cycling, tires have been sized using many different measurements. This is due to so tire companies throughout the world creating their own systems. Some systems used similar scales, but for different dimensions, further adding to the confusion! Luckily our good friends the ISO (International Standardization Organization) are here to save the day.
Once upon a time a situation arose where companies were trying to outcompete one another producing faster and lighter tires. Width measurements were falsely advertised, eventually leading to poor performing tires. This arrogance has subsided to the honest and accountable tire measurements in the modern age.
The width of a tire can also be confusing. A tire could be marked at 26 x 1.75 and another could be 26 x 1 3/4. These width measurements have different origins and are not interchangeable. If your tire's width is written a fraction, assume it will require a tire with the exact fraction to match. Likewise with the decimal measurement.
The diameter determines what rim the tire will fit on in inches (26", 27" etc) or in millimeters (650, 700c etc). Some riders preferred a thinner, "middleweight tire" to fit on the same rim. These tires could be marked at 26", but in reality might only be 25 5/8".
The ISO has persisted that the two important measurements are:
Common Fractional and Decimal Tire Sizes | ||
Size | ISO | Applications |
29 inch | 622mm | General 700c wide tires |
28 x 1 1/2" | 635mm | English, Dutch, Chinese, and Indian rod-brake roadsters |
28 x 1 1/4" | 622mm | Northern European designation for 700c tires |
27 x anything | 630mm | Older road bikes |
26 x 1 (650c) | 571mm | Triathlon, time trial, and small road bikes |
26 x 1 3/8" | 597mm | Schwinn lightweights |
28 x decimal | 622mm | Some German tire companies use this for 700c tires |
26 x 1.00 through 2.3 | 559mm | Most mountain bikes and cruisers |
26 x 1.25 | 599mm | Old US lightweights |
26 x 1.375 | 599mm | Old US lightweights |
20 x 1.5 through 2.0 x 2.125 | 406mm | Most BMX, folding bikes, trailers, recumbents |
The French sizing system uses letters to designate relative widths. A is narrow, D is wide.
Common French Tire Sizes | ||
Size | ISO | Applications |
700 A | 642mm | Obsolete |
700 B | 635mm | Rod-brake roadsters |
700 C | 622mm | Road bikes, hybrids, "29 inch" mountain bikes |
650 A | 590mm | French equivalent of the 26 x 1 3/8 for Italian high performance bikes |
650 B | 584mm | Utility bikes, tandems, loaded touring bikes, and some older Schwinn and Raleigh mountain bikes. |
650 C | 571mm | Triathlon, time trial, and high performance road bikes |