The remaining section of the structure is the front fork, DEF, and this carries both a compressive force and normal forces that cause bending about the point E.

In diagram (a) the front fork is shown in its orientation in the bike. The forces acting on it are known from calculations on the frame, and these are shown in magnitude and direction. Part (b) shows the same forces resolved parallel (compression of the fork) and normal to (bending of the fork) a reoriented fork. The compression force is 56.4 lbf. The normal forces must balance to avoid fork translation and are comprised of an 'upwards' force of 14.8 lbf at the axle, a

From: McMahon & Graham, "The Bicycle & the Walkman," Merion (1992)

'downward' force of 84.8 lbf at the down tube joint, and an 'upward' force of 70 lbf at the top tube joint. The bending moment due to these forces is shown on the next page.