A walk reel mower has a pivotal rear traction drum that can be selectively disposed in two different mowing positions that allow a single mower to cut grass on golf course greens as well as tee boxes with no degradation in cutting or power performance. The reel cutting unit has a pivotal rear shield to allow the rear shield to be pivotally adjusted to maintain its radial spacing relative to the orbit of the reel at a desired amount as the reel diameter decreases due to wear.