W Factor

If chain stay length and seat angle are held constant, as saddle height is increased the rider's weight distribution will shift more and more to the rear. To aid in discussions of this effect, Grant Petersen, the founder of Rivendell Bicycle Works has proposed a dimension he's dubbed W factor. W factor is the horizontal distance from the rear axle to the saddle as shown here.


W Factor is similar to another dimension called Rear axle to tail of saddle (X) which was included in BikeCAD version 10 at the request of Marty Walsh of Geekhouse Bicycles.