Electric Bikes
Northwest

Motor Wattage and Performance

Does the rated power of the motor determine electric bike performance?

It significantly does, of course. However, the motor's power rating tells only part of the story. It is rather a matter of what the system delivers, specifically how much current is put through by the controller, i.e. applicable power where literally 'the rubber meets the road', for how long high power can be sustained without overheating the motor and controller, how the motor's torque characteristics relate to specific riding conditions, and how conducive the bike's design is to concurrent pedaling.

How does the power level of the electric drive system compare to human power?

Most of us leisure riders seem comfortable pedaling somewhere between 50 and 100 Watt 'continuously' on our regular bike. 80 W of pedaling is miraculously all that's needed to glide along on level ground at 14 mph.

Of course, the pedaling effort that propels us with such ease on level ground proves woefully inadequate uphill.

Few of us can but briefly maintain 20 mph on level ground for which 170 W of pedaling is needed. While 170 W will propel an average weight rider up a 'moderately steep' hill of 7%, he or she shall crest at only 5 mph.

But in partnership with a quiet, smooth and stoic 250 W electric motor a rider of average weight shall manage the same 7% hill at 10 mph—while exerting no more concurrent pedaling effort than a comfortable 50 to 100 W! Examples of great 250 W drive systems include those found in the eZee Quando, Giant Twist, iZip Urbano, Vibe and Path.

On his or her electric bike the leisure rider thus commands a combined 300-350 W, which is the approximate 'continuous' power level at which the world's top riders amazingly race (although such riders are amazingly capable of pedaling at or just above 400 W for an hour or two).

What power levels do our customers prefer?

While over the years most of our customers have found 250 or 350 Watt optimal and preferable our spectacular higher powered bikes are now also selling well: The 500 Watt iZip Ultra, E3 Metro & Zuma, the 600 Stromer and the 750 W iZip Express.

Copyright © 2011 EbikesNW

December 2011