Last week I got my first commission. It was for a rear wheel built upon an existing rim. About reusing wheel components: Hubs? Yes. Spokes and nipples? Never. Rims? Judgment call.
There are many ways a wheel build can go wrong. You can get the lacing pattern wrong. You can get the spoke length wrong. You can have a 36 hole hub and a 32 hole rim. Your equipment can be poorly calibrated — truing stands need to be trued, even when they come out-of-the-box. Your wheelbuilder may be impatient. Rims may have slag around the spoke holes. The rim may be out-of-spec (circumference is too large or small) and/or not round. You can have a poor mix of hub, spoke, nipple, rim, and lacing pattern. Finally, and this list is not exhaustive, you can have improper tools.
I will choose only a few of these to expand upon (otherwise I’ll be writing all day on my off day).
Tools: Spoke wrenches come in different sizes and shapes. Spokes wrenches wear out and that can lead to the stripping of nipples because they won’t grip securely. We’re all familiar with the ubiquitous Park Tool red handled spoke wrench. It works for about 80% of the wheel build, but once you approach the ultimate spoke tension of a wheel, it becomes slippery to hold and its shape makes precision adjustments –1/16 of a turn — very difficult. At that point I transition to one of the excellent DT Swiss flat sided nipple wrenches. And always, always use the Twist-Resist spoke holder. Spoke wind-up is your enemy.
Assembly of components: There are certain combinations that just don’t work. Black spokes bind where they cross and when using them in a build the wheel requires more frequent stress relief. Aluminum nipples + any rim material = misery because aluminum nipples have more friction. The most challenging builds are: lightweight spokes (DT Swiss, Sapim CX Ray, or Sapim Laser), in black, with aluminum nipples. The spokes won’t slide together as the wheel tensions up, the spokes will rotate when turning the nipples, and the nipples will bind against the rim.
Rim quality control: No rim is truly round. Rims made by Hed usually are and that is why I prefer them. H Plus Son also seems to have good quality control. I haven’t built enough on Mavic to say either way. I have a first run of the new Open Pro UST (19 mm internal) and those built up ok.
The starting point of the rim determines the build experience and the quality of the wheel. When you build a wheel you change the shape of the rim. Build it up, build it down, and you will see that the rim which laid flat to start no longer does. This is why it is generally inadvisable to reuse a rim. But sometimes you do.
We start each wheel by selecting the right spokes, rim, hub and nipples. We recommend a suitable lacing pattern. Once we get it laced we leave a drop of Triflow between the nipple and spoke hole. We apply a drop of linseed oil to the spoke threads as thread lock. If we are reusing a hub we use spoke head washers to firmly seat the spoke head. If we are reusing a rim we use nipple washers to ensure even tensioning and to better distribute the spoke tension. Finally we build it slowly because cutting corners for speed leads to problems later.