Low gear VS high gear for range?

[coinmaster]

What will get me farther on flat ground, low gear vs high gear?
Low gear doesn't load down the motor so much but high gear is 3 times faster and I can assist it if only a little.

 

[billvon]

What will get me farther on flat ground, low gear vs high gear?
Low gear doesn't load down the motor so much but high gear is 3 times faster and I can assist it if only a little.

If you go the same speed won't make much difference. Low gear will likely be _slightly_ more efficient due to lower peak phase currents.

If you go as fast as you can in both gears, then low gear by a mile.

 

[dogman dan]

Bottom line, riding slower is incredibly more efficient than going faster. Regardless of what gear you may use. Partly this is because going just 2 mph slower means much less power is needed.

But as your power needed is less, the % of the total you can provide goes way up too, adding even more range.

Typical 20 mph cruise takes me about 500w. ( assuming some side wind) Typical rider input for a long ride is close to 100w. So at 20 mph, you put in 1/5th and the motor supplies 400w.

Bump to 30 mph cruise, pulling 1000w, and your effort is only 1/10th. Or zero, since most bikes are only geared for 25 mph or so. Legs a flapping, and nothing doing any good at 30 mph.

My favorite cruise speed for distance is 15-18 mph. Less that 15 mph just too slow, even for a recreational ride. If you keep the watts under 400, you can put in 1/4th with pedaling, or more if you are very fit. Range will easily double, vs cruising at 25 mph.