622 is the bead seat diameter. The rims are actually approximately 630mm but that varies a little. That leaves 70mm to account for the tires (35mm top, 35mm bottom).

Some bikes had a smaller front tire for smaller sizes to help shorter riders have better control, but I didn't think REI had any models with that feature. I also doubt they had any bikes with that feature for time trials or triathlons either. Smaller front wheels are not allowed in most competitions now.