For my Maxun One solar bike, I want to use a Bosch mid drive motor, whose weight has to be drastically reduced. Currently, a hub motor is used in the front wheel. The total weight of the solar bike, including the PV panels, battery and motor is currently 17 kg. A Bosch mid drive motor weighs about 4kg, which is far too heavy. In order not to increase the weight of the solar bike too much, the weight of the Bosch ebike motor has to be reduced, preferably to 1.5 kg.

I am looking for someone who has a lathe, preferably living in the vicinity of Maastricht (the Netherlands / Nordrhein-Westfalen), who like to carry out this project.
This Bosch Active Line motor is available for you and you can keep it:

Bosch mid drive motor weight reduction project
Bosch mid drive motor weight reduction project

The Bosch motor that I have available (4.1kg) is not the lightest Bosch motor, the 2.9kg Active Line is better suited for weight reduction, but unfortunately I do not have this one. 

It must be examined what the possibilities are for saving weight. For instance by replacing the gears by titanium gears and perforating everything as much as possible. Perhaps the motor can be replaced by an Astro motor with a higher speed and an extra gear transmission.

Do you have any comments? Please let me know.
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