4.7m (15ft) Boat Trailer: Determining Quad Roller Position

Note - if you are fitting adjustable quad wobble rollers to the trailer, omit this step.

If you are welding the rear quad rollers directly onto the trailer chassis, you first need to determine the correct position. If your boat is a flat hull without strakes, mount the quad roller U bracket approx. 485mm up from the centre of the cross member.

For straked boats, measure the strake position on the boat hull from the keel. Cut a rough cardboard profile of the hull with the position of the strakes marked on it.

Set the profile on the rear cross member, centred with the keel roller.

Position a quad wobble roller unit on the cross member and line it up until the rollers have clearance around the strake position on the profile. 30 to 50mm clearance from the strake to roller is adequate.

Mark the quad arm centre position on the cross member. This mark is the centre for the quad roller U bracket.


 If required lengthen or shorten the quad wobble arm to suit the strake positions.