The Zero is intended to be used with aluminum alloy rims, but not all alloy rims are entirely aluminum.
You should use our interactive wheel-checking tool online to help guide you through the checking process.
There are two ways that primarily-aluminum wheels can be incompatible with the Zero.
Type 1: Steel-beaded tires
Some tires include steel in their construction, usually in the bead. This can lightly attract the Zero's magnets the whole way around the rim. For the Base and Powermeter models, it will occasionally make it annoying to set the magnet distances, since if the magnets get too close, they will try to jump all the way to the rim. For the Halcyon, steel-beaded tires are incompatible. In our experience, they're typically included as the OEM tire on many road or hybrid bikes.
How to detect a steel-beaded tire?
If you run a strong magnet (not flimsy fridge magnet) around the rim and it is lightly attracted the entire way around, you probably have a steel-beaded tire.
For the Base and Powermeter models:
- Clamp the magnet quickrelease tighter. This should be enough to keep the magnets from moving for most wheels and tires. Note that this does not work with the Halcyon, as the magnets need to be able to move freely.
For all models:
- Remove the steel-beaded tire during your winter off season.
- Switch to a "folding" tire, which typically have Kevlar beads. Most tires found tightly-bundled in bike shops are the "folding" style and can be quite inexpensive. You can check for certain whether a given tire is steel-beaded or folding simply by running a magnet around it and seeing if it is ever attracted.
Type 2: Steel pins
Some wheels include steel pins leftover from the manufacturing process. These can vary in their size, but typically make the wheel incompatible with the STAC Zero because of the amount of attraction the magnets feel to the big chunk of steel. When riding, the magnet arrays will tend to pulse each time the steel pin goes by, and may change their position annoyingly.
How to detect a steel pin?
If you run a strong magnet around the rim and it is strongly attracted at on point (usually opposite the filler nozzle), then you have a steel pin.
- There are many wheels like the Mavic Open Pro or Shimano R500 that do not include steel pins and are quite inexpensive. We recommend picking up one of them.