bicycle frame dimensions

Handlebar drop by default is the vertical distance from the center of the saddle to the center of the handlebar. However, this measurement does not necessarily have to start at the center of the saddle. The location on the saddle can be changed by altering the saddle reference point.

Rider Compartment or Cockpit by default is the horizontal distance from the center of the saddle to the center of the handlebar. However, this measurement does not necessarily have to start at the center of the saddle. The location on the saddle can be changed by altering the saddle reference point.

Saddle setback is the horizontal distance between the bottom bracket and the front tip of the saddle.

BikeCAD displays the Saddle tip to brake hood measurement in two forms: Direct and Projected. These dimensions are illustrated above. The direct distance is displayed in BikeCAD with an * symbol to denote the fact that the dimension is actually

Setback is the horizontal distance between the bottom bracket and the seat tube - top tube intersection.

Note that for sloping top tube bikes, BikeCAD measures setback according to the effective seat tube length. This may not be in agreement with everyone's definition of setback.

Stand over height is the distance from the ground to the top of the top tube. In the case of a sloping, or a curved top tube, we take the measurement at the midlength of the tube as shown.

In BikeCAD, Fork length is measured from the axle to the crown in a line parallel to the steerer tube. BikeCAD also provides another fork measurement which is the direct distance from the axle to the crown.

Seatpost setback is a measure of how much the seatpost clamp is offset from the center of the seatpost.

BikeCAD defines saddle height as the direct distance from the center of the bottom bracket to the reference point on the saddle. The reference point is by default the deepest part of the saddle, where it may dip down in the middle. However, this point can be changed according to the instructions here.