The Ease, a portable (friction drive) motor unit.

[LockH]

Seen here:
http://www.bikebiz.com/news/read/portable-propulsion-pack-turns-any-bike-into-an-e-bike/020664

... the claim from engineers at a university in Singapore. Doctoral candidate Felix Römer says the Ease unit can be easily attached to almost any bicycle, turning it into a e-bike. (Any town bike, that is, because the propulsion is via contact with the tyre, and MTB knobblie tyres won't work it.)

Article ends:

"The unit has optical sensors that detect when the pedals are being pushed," said Römer.

"Most pedelecs feature these sensors permanently installed in the bicycle's bottom bracket. It took quite a lot of time and trouble to get everything to work properly without cables or additional equipment."

The 250-watt device features a lithium battery enabling a range of up to 50 kilometeres. Römer claims the 3.5 kg unit can be attached to a bike in ten seconds.

"Nothing stays on the bicycle after the unit has been removed," said Römer, who is now seeking an industry partner to commercialise the technology.

Contact: Felix.roemer@tum-create.edu.sg

 

[LewTwo]

• 250-watt device
  3.5 kg unit
  range 50 kilometers

Why is it that I think the range estimate is a tad "optimistic" ?

 

[Hillhater]

As with any "pedal assist" system, the range is unpredictable depending on how hard you pedal, the terrain, wind, weight, etc etc.
Fit eager 150lb rider on the flat with a tail wind...sure 50km is possible.
Fat lazy 300lb guy with touring packs etc, up a windy mountain pass.....maybe 2 km ! :wink:

 

[LockH]

^^ Hehe... Watt he said. Maybe see also "marketing".

 

[LewTwo]

As with any "pedal assist" system, the range is unpredictable depending on how hard you pedal, the terrain, wind, weight, etc etc.
Fit eager 150lb rider on the flat with a tail wind...sure 50km is possible.
Fat lazy 300lb guy with touring packs etc, up a windy mountain pass.....maybe 2 km ! :wink:

Right. I can get 100 mile range from 7Ahr battery ... If I pedal for the last 90.