There are a number of factors that go into determining if a crank is compatible with our power meters and if it is a crank 4iiii supports.
Crank materials: In order for our power meters to achieve +/-1% accuracy, the crank materials need to respond the exact same way throughout the life of the crank. Any change in the material structure will cause the power readings to be inaccurate. Ex. We have found with certain carbon cranks, their structure can change over time, which deems our product incompatible.
Crank shape: Our power meters require an appropriate surface to install on. In general we need a smooth flat surface, with enough length and width to accommodate our product.
Product popularity: Our compatible product list is also based on the popularity of the crankset and those customers wanting a power meter. We require enough interest and demand for a crank to be considered for validation.