Pickup bed delete or cab chassis (C&C)?

ticki2 wrote:
If you take a good look at a c&c truck and take some measurements I think you will find that the axle bump stops will prevent the wheels from ever going above the truck frame so there is really no need for a hump above the flatbed unless you have oversized wheels/tires . You just have to watch the flatbed framing so the wheels have a pocket under the deck . The narrower axle on the c&c is the same width as a srw pickup so you can also convert to srw by removing the dually spacers on the front hubs and use srw wheels .

If one side of the axle is in full contact with its bump stop while the opposite side of the axle is furthest away from its bump stop, then the outer shoulder of the tire furthest outboard on the side of the axle in full contact with the bump stop will be higher than the frame.

The axle and tire assembly is a rigid straight line approximately 94" long inclusive of the outer tires in a chassis cab dually, with a radius of 47" from an assumed central pivot point at the pinion.

The chassis cab frame is 34" wide web to web, with the bump stops under slung on the lower flange... so let's call the initial contact point of taper tipped bump stops 1" inboard from the web, supported by a 3" wide flange. Hence, the radius of the initial contact point of the bump stops is 16".

We can make a horizontally level example stick that is 47" long, painted with bright marks at 0", 16", and 47".

We can place this stick on a table that is pushed up against a wall, where the wall has vertical measuring marks on it in one inch increments, where 0" is table height, and 6" is as high as we need to measure.

We can then move our stick on the table such that the 16" mark on the stick aligns with the vertical measuring line on the wall.

If we anchor this stick to the table at the 0" mark on the stick, and fix our gaze at the 16" mark on the stick that coincides with the 0" mark on the wall, while raising the unanchored end of the stick up until the 16" mark is about 5" above the table... how high will the 47" end of the stick be?

5" approximates the maximum axle travel available between the axle and the bump stops. In an extreme twist ditch maneuver, such as what may be encountered crossing a drainage gully over a fire road, one side of the axle may be all the way down in the ditch, while the other side of the axle is compressed all the way up on an embankment.

The 62" difference in width, or 31" difference in radius, between the bump stop versus the outboard edge of the tire (that itself is 16" higher perpendicularly to the axial center of the straight line), dictates that the outer ends of the tires can extend higher than the tops of the frame rails when one end of the axle is in full jounce while the other end of the axle is in full rebound.

Body building guides available from the chassis cab manufacturers recommend making allowances for this.