A wheelchair 3, wherein said primary spring and said secondary spring are adapted to compress upon upward movement of said front caster wheel, and wherein {HEAD ~ said secondary spring} has {TAIL ~ a higher compression range} than said primary spring 
has
A wheelchair 3 , wherein said primary spring and said secondary spring are adapted to compress upon upward movement of said front caster wheel , and wherein { HEAD ~ said secondary spring } has { TAIL ~ a higher compression range } than said primary spring
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH