A collapsible trailer to be towed by a bicycle has {HEAD ~ front and rear U shaped members} pivotally mounted on {TAIL ~ an axle} to the ends of which wheels can be attached 
pivotally mounted on
A collapsible trailer to be towed by a bicycle has { HEAD ~ front and rear U shaped members } pivotally mounted on { TAIL ~ an axle } to the ends of which wheels can be attached
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH