Wheel Building 101: Basic rules for crafting a custom wheelset

Overall, a consists of a hub, a number spokes with spoke nipples and a rim. Everything else, such as the freehub, cassette, axle, brake discs or tyres, will be covered in other articles. How carefully these components are selected and combined with each other determines the service life of the wheel. These days, there are a lot of good ready-made wheels or system wheels to buy, which is why not every shop always builds their own wheels themselves any more. System wheels are available in light, stiff, robust or budget models. However, they are often characterised by the use of manufacturer-specific components. Therefore, one is dependent on the specific component in the event of a defect. This is where a wheel needs to suit the needs of a wider range of people. When you build your own custom wheel, you can tailor it to suit your needs, but it does require a greater amount of effort.

Materials – What are wheels made of?

When it comes to hubs and spokes, the bicycle industry is almost unanimous: hub bodies are made of aluminium and spokes are made of steel. There are also spokes made of aluminium, titanium, carbon or textile fibres, or hubs with carbon parts; however, they have a relatively small presence on the market overall. Rims, on the other hand, were often made of steel in the past, but are now mostly made from aluminium and more and more often from carbon. Aluminium rims are cheaper, and carbon rims can be precision-crafted to conform to the desired level of stiffness or flexibility. Aluminium can also be anodised in a variety of colours, allowing for even more wheel customisation.

The Spoke Nipple

The nipple has an inside thread and is screwed onto the spoke. It is inserted from the outside through the rim onto the spoke, and screwed with the head against the rim base. To make installation easier, most nipples have a slot in the head, and some nipple heads are hexagonal or are shaped like a hex key, also called a torx tool. The square sleeve nut that you attach the spoke wrench to has a standard dimension of 3.23 millimetres – older wheels may have other dimensions. A suitable nipple tensioner, also called a spoke wrench, prevents unnecessary wear on the nipple.
Nipples are available in brass and aluminium. While alloy nipples are two-thirds lighter than brass nipples, the latter are more resistant to corrosion, so are recommended for all-season city bikes or winter training equipment. There are also nipples in different lengths, with the most common being 12-millimetre nipples. Longer nipples (14 mm, 16 mm) theoretically provide more threads to hold or compensate for shorter spokes. Some rims have a very strong rim base, while others require shims, such as Newmen rims. Even then, longer nipples are generally advisable.

Rims and Rim Designs

The rim holds the spoke nipples on the inside and the tyre on the outside. Rims for rim brakes have a brake flank and wear out over time, while rims for disc brakes can be designed without this feature, which makes them lighter and theoretically extends their service life. Under no circumstances should you combine disc brake rims with rim brakes! In the past, rims were U-shaped, i.e. they consisted of only one wall; they were also called box rims. In order to achieve more rim stability, especially when aluminium became the material of choice, so-called double wall rims were constructed, which were given a second rim base. This is still the prevailing design today, even for carbon rims. An interesting recent exception is the 3Zero Moto from Zipp, which is constructed from carbon but sporting the old box shape, allowing it to intentionally flex without breaking. Most rims are symmetrical, but there are also those with asymmetrical profiles to help compensate for corresponding hub assymetry.
The spoke holes in many rims have either a right or left orientation.

Calculators – the path to finding the right spoke length

To figure out the correct spoke length, you can turn to one of the many spoke calculators on the internet. The advantage of using calculators from large manufacturers is that they are based on reliable databases which store information on commonly-used rims and hubs. However, it won’t hurt if you measure components yourself and cross-reference data in the database. You’ll need the ERD of the rim, the dimensions of the hub (see there) and the number of spoke crossings.

Necessary Tools

The most important tool for wheel building is the truing stand. All models can be used for different wheel diameters, rim widths and axle dimensions. There's a wide price range between basic, single-sided versions like the Pro Truing Stand 2.0 from Feedbacksports and professional-grade equipment like the Truing Stand from DT Swiss. The model TS-2.2P from Parktool has a host of various accessories, from thru-axles to dial gauges TS-2Di, which you won't want to go without once you've used them.
Models that don't align themselves need to be calibrated every so often with a truing gauge like Park Tool's 1554-1. Alternatively, you can check the alignment of the wheel with a wheel truing gauge.
To tighten the nipples, you need nipple tensioners that fit properly – usually the 3.25 millimetre spoke wrench will fit modern nipples. Examples include the red Spokey and the Universal Key from DT Swiss. In the case of bladed spokes, it is recommended to use a spoke holder (e.g. Sapim's spoke wrench for CX/CX-Ray). System wheels from Mavic or Fulcrum require their own spoke wrenches for servicing. Other special tools help to insert the nipple securely into the rim and make the first turns easier. To perfect your wheel, it is also advisable to use a spoke tensioner (Parktool TM-1 or DT Swiss Tensio 2), which allows you to easily determine the tension of the spokes.