| Here [1] is an electric-assist bike I recently purchased which can be configured to: * Measure one's pedal torque and cadence, thus calculate and display "Human Watts" input to the bike while cycling (update rate = once per crank rev) * Supply a configurable amount of electric-motor power assistance directly proportional to one's "Human Watts" input -- at selectable, configurable, default power amplification factors of 0x ( assist off ), 1x or 2x. With this instrumented, pedal-power-amplified bike I've found: * I won't break a sweat if I keep my "Human Watts" below about 30 to 60 (power assist on or off, doesn't matter) * Breaking 100 - 150 "Human Watts" for more than a few seconds will break a sweat for me. * (Off topic ) Efficiency comes out to an excellent 2 to 4 Watt-Hours-electric per mile with my settings and low-power riding style, having gotten over 100 miles on my first, not-yet-fully-depleted battery charge. It's also possible to configure a throttle power control to deal with hills where my "no sweat" rate of 50 Watts -- even with 2x power assist -- won't make it up a grade. But I configure the throttle as disabled as I don't have hills like that on my commute. I config pedal power amplification for a cut-in speed of 6 mph and a cutoff speed of 13 mph just right so as to stay dry and safe for me and those around me. Un-assisted cyclists frequently pass me; that's fine. I stick to what roads on my commute have painted bike lanes. My scariest road encounter (a motorist who crowded me toward the curb with his car, twice) would have been impossible were I riding in a protected bike lane and making the kind of protected right turn this new design affords. Edits for clarity. --------------- [1] http://www.ebikes.ca/shop/edgerunner/full-bikes/edgerun-stok... |