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Solar trikes with serial hybrid transmission: technical solutions for the future ?

20.02.2021 - Bernard Cauquil
Bernard Cauquil Bernard Cauquil
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TiltDragonFly in the ascent of the Mont Cenis pass
Mont Cenis pass

Rolhoff Speedhub, Hybrid serial transmission, Direct drive motor, belt drive: A highly efficient quartet

Data analysis on a challenging 185 km route with the Tourmalet pass climbed by La Mongie. Of course still in serial hybrid transmission with my trike “TiltDragonFly”.

On a track such as this, the use of Rolhoff Speedhub allows the best performance from the RH212 direct drive without the need to use “statorate” fluid or other cooling accessories to evacuate joule losses.
The motor always operates within its maximum efficiency range regardless of the road gradient.

Overall efficiency increased by energy recovery during braking thanks to an original modification of the Rolhoff speedhub.

The use of standard toothed belts also ensures quiet running and maintenance-free operation.

Trace GPS

Data recording analysis

energy consumption data
energy consumption data
  • distance : 184 km
  • duration : 6 h 55 mn
  • average speed : 26,6 km/h
  • ascending elevation : 2335 m
  • gross energy consumption : 2392 Wh
  • regenerative braking : 344 Wh soit 16,8 %
  • net consumption : 2048 Wh
  • net consumption per km : 11,1 Wh/km
  • pedal generator production : 585 Wh i.e. 3,18 Wh/km
  • average hourly production : 84,5 Wh/h
  • relative consumption : 1463 Wh
  • relative consumption per km : 7,92 Wh/km
energy produced by the pedal generator
energy produced by the pedal generator

I have finally weighed my trike, empty 70 kg all round

  • Weight of “TitDragonFly” at the start (with full water and tools): 73 kg
  • Weight of the driver this morning at the start : 74 kg
  • gross consumption: total consumption before deduction of energy recovered by regeneration
  • net consumption: gross consumption – energy recovered by regeneration
  • relative consumption: net consumption – energy produced by the generator.

Assessment of this new test day in series hybrid transmission

The results of this new test corroborate those obtained previously: the relative consumption depends very little on the relief of the course and its length. With Edgar Tournon we had already made the same observation throughout the Suntrip 2020 road.

On TiltDragonFly, 2 technological innovations explain this phenomen on to a large extent:

  • The efficiency of the RH212 engine is optimal (around 82%) both on the flat road and on mountain roads thanks to the Rolhoff speedhub.
  • The variable regeneration that allows me to recover a significant percentage of the energy used to climb the passes.

Rolhoff Speedhub


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