Innovative Energy Engineering



Wheels

Wheels consist of a center hub, spokes, and a rim. Most wheels are machine-built with factory-selected parts and are relatively inexpensive. There are also specific light options that can cost more than a good bicycle. A custom-hand built wheel is not necessarily cheaper, but can be built with specific components and can be repaired. If designed and built correctly, a hand-built wheel will last a very long time.

For any wheel it is important to be radially and laterally true and for the spokes to have the correct and even tension. One may think this is how a wheel comes out of the factory, but that is not always the case. Over time wheels also can become untrue, spokes can get loose and the wheel needs to be re-trued. Truing can be done by anyone with some patience (never rush a wheel truing or built!). A wheel can be built and trued in the bicycle with just a spoke wrench. however, it is just easier and nicer to use better tools. I prefer to do the work inside my house without being rushed in an awkward position in the garage. My position is if it is easier to true a wheel, I'm more likely to actually do it. Here are the tools you want (if not need):

Hubs

Front hubs only contain bearings. Rear hubs also contain the free-hub (the ratchet mechanism that lets you coast and often makes a fast-clicking sound)that connects to the cassette. cup-and-cone bearings (also called loose bearings) are adjustable and maitnainable. the loose ball bearings should be replaced at every service and the cones (if pitted) can be replaced, but are costly. the inner race is not replaceable and if pitted requires hub replacement. however, if serviced frequently, wear is minimal. Newer hubs use Cartridge bearings. those are not serviceable and get replaced completely when worn. those last a long time and the hub theoretically should last very long since the "inner race" gets replaced with a new cartridge bearing. Cartridge bearings are not very expensive (cheaper than possible cone replacements) and all more expensive hubs use cartridge bearings. Shimano appears to be the only premium manufacturer to still offer quality cup-and-cone hubs. Most cup-and-cone hubs are for budget bikes.

Differentiating factors between cheap and expensive hubs are the seals (to prevent water and dirt to enter) and the rear ratchet mechanism. Cheap hubs can work well when serviced, but if riding conditions are rough (dirt, water, hard riding), cheap hubs can fail. Some hubs can cost as much a entry level bicycles, I doubt it is necessary to spend that much. Note that hub failure and replacement often requires wheel re-built. Most cheaper hubs are not re-buildable. Some hubs also contain a dynamo to generate electricity and Internal Gear Hubs (IGH) contain a planetary gear system. hubs need to be selected for the spacing (e.g. 135 mm Quick Release for rear hubs of older MTB or 148 mm Through Axle for newer MTB) and the number of spokes needs to match the rim.

Hubs also hold the disc brake rotor by means of a center-lock or a 6-bolt system.

Rims

Modern rims are made of aluminum or carbon fiber and are double-walled. Single-walled rims are used for fatbikes to save weight. If rim brakes are used, the rim must have a specific brake surface that will wear out over time. Number of spoke holes needs to match the hub. Rear wheels have large offset (dish) and off-center rims with off-center spoke holes can equalize drive side and non-drive side spoke tension (drive side spokes have more tension). To prevent cracks around the spoke holes some manufacturers include eyelets. If the rim has no eyelets it is recommended to include nipple washers.

The rim should be selected based on the expected use and rider weight. ASTM F2043 details usage scenarios from a (paved road) to 5 (extremely harsh trails). See the reference below for details. Heavier riders or riders with expected touring cargo loads should select rims with a higher rating. The right inner rim width depends on the tires used. This article gives guidance on rim and tire sizes. With a given material the rim typically gets heavier with wider width and larger load category.

Rim width depends on the prospective tire size. DT Swiss lists compatible rim and tire sizes.

Spokes

Spokes connect the rim and the hub. typical modern wheels have 32 spokes each. In an effort to appear weight-saving the number often is reduced. This may sound logical, but either requires heavier rims or causes less stability. Fewer spokes (more tension on each spoke) are harder to true and if a spoke breaks on a ride, it may be impossible to ride back because the wheel will be too much out of true. Wheels for heavier riders should or heavy touring loads should have 36 spokes. Most factory wheels use aluminum nipples, but brass nipples are sturdier.

Most factory wheels come with 14 gauge (2 mm) or 15 gauge (1.8 mm) straight spokes. It is much better to use double butted spokes (both ends of spoke are thicker) or triple-butted spokes (rim end thicker and hub end even thicker). This brings more material to where spokes typically break (at hub or rim) and the thinner middle allows more stretch to distribute the load from one spoke over many spokes.

For disc brake and drivetrain wheels the most common and strongest lacing pattern is 3-cross. Large hubs may or smaller wheels may require 1- or 2-cross lacing.

Additional Information

 

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