You have to make 2 bogies (each with 2 axles) like the LGB 99 7245 (HSB 5-coupler):
An R1 circle has a diameter of just under 4 feet and an R2 circle just over 5 feet. An R3 circle is bigger still.
LGB R1 is about 51-5/8 inches from edge to edge. The playmobil plastic track is just under 4 feet.LGB track dimension can be seen here: www.lgb.com/media.php/lgb/LGB_Gleissystem-Info.pdf