The invention relates to wheeled vehicles, such as wheelchairs (1700), that are adapted to traverse obstacles (300). The wheeled vehicles include a frame (102), first and second drive assemblies (130) that each include a drive wheel (132), first and second suspension assemblies (1706) that each include an anti-tip linkage (1711) and a shock absorber (172) with a spring return, first and second front anti-tip wheels (120) positioned forward of the drive wheels by the first and second anti-tip pivot arms (1790), first and second rear anti-tip wheels (108) positioned rearward of the drive wheels by the first and second anti-tip pivot arms (1734).
