My SA 5w has done my 5 all time best 44.63 to 45.79 mph, and also my 5 longest up to 126 miles. Hill is less than 1/3 mile and just around 10%. On a wired real speedometer. GPS ??? Pffft The few times I tried, Map-my-ride has been consistently off 8 miles on 80 mile courses, useless.