A wheelchair comprising: a frame; a seat supported by the frame; a first drive assembly comprising a first motor and a first drive wheel that is driven by the first motor; a second drive assembly comprising a second motor and a second drive wheel that is driven by the second motor; at least one rear caster; wherein said first drive wheel, said second drive wheel, and said at least one rear caster engage a horizontal support surface when the wheelchair is at rest in a normal operating position on the horizontal support surface; first and second rigid arms fixedly connected to the frame; first and second front idler wheels rotatably connected to the first and second rigid arms such that positions of axes of rotation of the first and second idler wheels with respect to the frame are fixed; wherein said first and second idler wheels are spaced apart from the horizontal support surface when the wheelchair is at rest in the normal operating position on the horizontal support surface; characterized by: a first suspension assembly that couples the first drive assembly to the frame such that the first drive assembly is movable relative to the frame; a second suspension assembly that couples the second drive assembly to the frame such that the second drive assembly is movable relative to the frame and relative to the first drive assembly; wherein the first and second suspension assemblies (106, 107) comprise an angled pivot arm having a substantially linear forward link, a substantially linear rearward link, and a pivot connection connecting the angled pivot arm to the frame and situated between the forward and rearward links (180, 182), wherein the forward link extends beyond a forward section of the frame, the rearward link extends beyond a rear portion of the frame, and the rearward link extends angularly upwardly relative to the forward link and includes at least one rear caster connected thereto. a frame; a seat supported by the frame; a first drive assembly comprising a first motor and a first drive wheel that is driven by the first motor; a second drive assembly comprising a second motor and a second drive wheel that is driven by the second motor; at least one rear caster; wherein said first drive wheel, said second drive wheel, and said at least one rear caster engage a horizontal support surface when the wheelchair is at rest in a normal operating position on the horizontal support surface; first and second rigid arms fixedly connected to the frame; first and second front idler wheels rotatably connected to the first and second rigid arms such that positions of axes of rotation of the first and second idler wheels with respect to the frame are fixed; wherein said first and second idler wheels are spaced apart from the horizontal support surface when the wheelchair is at rest in the normal operating position on the horizontal support surface; characterized by: a first suspension assembly that couples the first drive assembly to the frame such that the first drive assembly is movable relative to the frame; a second suspension assembly that couples the second drive assembly to the frame such that the second drive assembly is movable relative to the frame and relative to the first drive assembly; wherein the first and second suspension assemblies (106, 107) comprise an angled pivot arm having a substantially linear forward link, a substantially linear rearward link, and a pivot connection connecting the angled pivot arm to the frame and situated between the forward and rearward links (180, 182), wherein the forward link extends beyond a forward section of the frame, the rearward link extends beyond a rear portion of the frame, and the rearward link extends angularly upwardly relative to the forward link and includes at least one rear caster connected thereto. a first suspension assembly that couples the first drive assembly to the frame such that the first drive assembly is movable relative to the frame; a second suspension assembly that couples the second drive assembly to the frame such that the second drive assembly is movable relative to the frame and relative to the first drive assembly; wherein the first and second suspension assemblies (106, 107) comprise an angled pivot arm having a substantially linear forward link, a substantially linear rearward link, and a pivot connection connecting the angled pivot arm to the frame and situated between the forward and rearward links (180, 182), wherein the forward link extends beyond a forward section of the frame, the rearward link extends beyond a rear portion of the frame, and the rearward link extends angularly upwardly relative to the forward link and includes at least one rear caster connected thereto.