Fuchs : Principles of Human-Electric Hybrid Drives for HPVs

This paper was meant to be presented at the 6th European Seminar on Velomobile Design, Copenhagen 2009, but the author could not be present, and due to shortage of time it was skipped.


This paper discusses the basic configurations of drive systems for human electric hybrid vehicles.

The e-bikes on the market today are parallel hybrids (PHEB, parallel hybrid electric bicycle). In parallel hybrids it is attempted to mechanically add the highly variable torque of a pedalling human with a constant torque of an electric motor. Some vehicles have the motor near the bottom bracket, while others use motors near or in the front or rear wheel. A special case of a parallel hybrid is Michael Kutters drive system where electric and human power are added using a planetary gearset in the rear wheel hub.

In a series hybrid human electric hybrid (SHEB, series hybrid electrical bicycle) human power is converted into electric power using an electric generator driven by the pedals. Mechanical drive power to move the series hybrid vehicle is produced by a motor driving the wheel just as in the case with the parallel hybrids having either a front wheel or rear wheel (hub) motor.

The different kinds of hybrid drives and their disadvantages and benefits with respect to use in recumbents and velomobiles as well as in upright cycles are discussed.

(PDF, English, 2884 KB)

About the author

Andreas Fuchs

Andreas Fuchs

22.3.1963, Thun (Switzerland)

By education a climate and a medical physicist with focus on biomedical resp. rehabilitation engineering, makes a living in engineering and in applied and industrial R&D.

Expert for (small) electric drives: Longest track record of R&D for the chainless series hybrid drive for velomobiles and other assisted human powered vehicles and lots of knowhow about drives for electric power-tools.

Co-organizer of the series of european velomobile seminars since the beginning in 1993. At the moment works for a US start-up company bringing to market electrified recumbents, and helps Hannes Neupert of http://www.extraenergy.org to promote a standard for interfacing components for electric drives of lightweight electric vehicles, http://www.energybus.org.


Andreas Fuchs
Dr.phil.nat, Physicist
Master of Advanced Studies ETH in
General Medical Physics and Biomedical Engineering
Gutenbergstrasse 24
3011 Bern, Switzerland
Tel/Fax +41 31 301 56 36
Mobile +41 79 294 06 93