Helper engines for bicycles

Rubbee is a bicycle helper engine that attaches onto the seat tube of your system uses friction - one of the oldest ways to transfer energy, but it usually has low efficiency.The friction drive module can be used on  most standard bicycles on the market and provide up to 25 km/h top speed (which is the EC top allowed speed for an electric assisted bike) and 25 km range without pedaling . But as you can see you cannot  have a rear rack and rear fender on your bike. Usually the rear-rack on modern cycles are easily dismantled, so this should be no problem to attach Rubbee, and it would acts as a fender itself.

The design looks great and I would think it is a good product based on what I can see. I would prefer something that attaches to the front wheel instead of the rear wheel.

There is still time to fund it on kickstarter here:

Revolutionary? 

The product is branded as revolutionary on its founding and web page:

  "Rubbee is a revolutionary electric drive which can be mounted on any bicycle in just a few seconds."

This is hardly true, in general, even though that the execution and timing of the product might be better then earlier attempts. (Peak for export oil occured 2004-2005) Comparable helper engines showed up early in the fossile fueil combustion engine era, this one is from 1952:

This image is from http://www.veteranmoppesida.se, see more combustion helper engines for bikes here.

Additionally this project is very close to Sir Clive Sinclair projects "Zeta", there is a lot of similarities. See the patent here EP 1031505 A1.

See also the below images and videos of the Zeta: