Extension for BackPower bicycle rack for trailer coupling, 4th wheel

For the extension to four bicycles, an extended rail holder is attached to the bicycle carrier. Both the 3rd wheel rail and the 4th wheel rail are then screwed onto this. The third bicycle is attached to the frame as usual with a support arm, the fourth bicycle is attached to the third bicycle with a double support arm from frame to frame. The extension increases the weight of the carrier by +4 kg.