Locking bed knife blade adjustment allows precise setting for a clean cut. No engine also pays off with low maintenance. No spark plugs. No oily rags. No running to the gas station or hardware store to get supplies or parts.
Reel mowers are simple mowers.
Brush them off occasionally. Spritz the blades with WD-40. And sharpen them every other season. Rotary mowers tear at the grass, hacking off the tops of blades and leaving them open to disease. Reel mowers snip the grass, cutting each blade like a pair of scissors.