{HEAD ~ The set} of {TAIL ~ wheels} is arranged substantially on a line extending through the arbor 
of
{ HEAD ~ The set } of { TAIL ~ wheels } is arranged substantially on a line extending through the arbor
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH