Sunday, January 13, 2013

It's not so easy

In December I bought a Golden Motor Smart Pie from the European distributor Devi Motion. I compared several makes like Crystalite and Bionx. Bionx is probably the best you can get but expensive. Crystalite looks very OK but did not sell LiFePO4 batteries yet. This new battery is more expensive but also more durable than lithium polymer batteries.

My job is 20 km away. It is a nice trip partly along a channel and almost always on bicycle paths.  I live in Breda and my job is in Raamsdonksveer which is to the North East relative to Breda.  We have winds from the west mostly and in the in the morning it is a 45 minutes drive but in the evening it can be more than an hour.

One of my hobbies is velomobile design and I did use my plywood velomobile. But it is a prototype still and after a few weeks the body was broken. A velomobile is a very comfortable solution when its cold, windy and raining. But getting in and out, traffic lights and sharp corners takes more time.

Street legal E-bikes are no solution for me: my cruising speed on the bike is almost the same as the cut out speed of the electric motor. I would like to have assist up to 30-35 km/h. This is the reason I have bought an E-bike kit.

It took me one evening to mount the kit on my MTB. I enlarged the width of the drop out of my Rock Shox Judy suspension fork. The E-motor axle had to be modified too (Thank you Jeroen).

The first ride was very much fun. The motor was so strong that I could not keep up with it. But the battery was empty half way the return trip from Raamsdonksveer... At home I discovered that the drop outs were broken. Very dangerous. I could have broken my neck...

I have bought a new fork and reprogrammed the motor controller. The motor current is limited to 2 ampere now and I hope the motor torque is now limited to safe values... If you plan to buy a motor too these are my tips for you:
  1. You should use a torque arm. These arm are not included in the kit (They should be).
  2. It is not a plug and play kit. There is no manual. There are no warnings. You can make very big and dangerous mistakes.
  3. Programming is a lot of trial and error: there is no instruction that explains what all the settings do.
  4. I have invested about 8 hours in this project and still have not reached a satisfying result. 

No comments:

Post a Comment