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