By Brad Quartuccio
Rim replacement is a fairly common repair, and well within reach of the competent mechanic that has yet to perform a ground-up wheel build. If you can true a wheel, you can replace a rim. Brakes pads can slowly wear through the sidewall over the miles, a sharp edged pothole can badly ding the edge, or an old fashioned wreck can leave you with a rim bent beyond truing. Assuming the wheel isn’t full-on taco’d with bent spokes and the nipples aren’t corroded beyond turning, in most cases the spokes and nipples themselves are perfectly fine to reuse. With an identical or very similar rim you can move the spokes over one-by-one preserving the lacing pattern and spoke head angle, and taking much of the mystery out of a wheel build.
The ideal situation is to find an identical rim to the one you are replacing, but sometimes that is near impossible given model year changes, in which case you must choose a rim with the same spoke hole number and an effective rim diameter (ERD) the same or very close to the original. ERD refers to the diameter of the inner wall of the rim where the spoke nipples engage and is one of the key measurements in wheelbuilding that determines spoke length. In order