I would like to use zwift but after having installed the app on my iOS device, it is required that I specify my wheels diameter. They are 29" wheels, but I can’t find these in the list. What should I do ? What would be the consequences of specifying wrong diameter in the app ?
Sound like you would be using zPower anyways (which is just estimated watts based on wheel speed and the power curve of the trainer) so I would just suggest using 700c until Zwift implements 29" wheels. The difference will not be that much.