Truck Rack

A robust truck rack having continuously adjustable uprights and crossmembers is disclosed. A telescoping upright is formed by an inner tubular member sliding within a larger outer tubular member. The upright is locked in place using two differing locking mechanisms. A first mechanism relies on a generally rectangular slide plate positioned within a T-shaped channel formed on the inner tubular member which is then clamped in place such that the inner and outer tubular members are held in place via a frictional coupling. The second locking mechanism affixes a projecting stop plate onto the inner tubular member forming an affirmative stop preventing the inner tubular member from moving beyond the stop point. A continuously adjustable crossmember-siderail coupling mechanism is disclosed.