Mowed both lawns again yesterday in 90 degree heat. I did a little calculation on how many steps it takes to mow the hill. It takes 10 to 12 steps and approximate 40 passes to complete each hill. 1/2 would be 20 uphill passes. 30 degree is pretty close to most stairs. Doing both yards is like walking up 40 flights of stairs (approx). The scene from Ghost Busters when they have to walk up the stairs to fight the evil spirit comes to mind. I had to stop yesterday on the neighbors yard, the lawn boy was set on 2nd gear which was pulling up the hill too fast (with his trees in the back I left the hill as one section, so I went up and down right after another, normally I include the hill with the entire back yard so I have time to recover). About 3/4 of the way through the hill I almost pass out. I had to take a 30 minute break before started mowing again. When finished the hill I set the LB on 1. The duraforce is fast in 2nd and 3rd. 3rd is 4 mph speed, almost too fast. Once I regulated the hill speed I was much better.