I have not built anything yet. But want to!
My e-bike is a crank motor type (by Bosch) and provides various assist levels up to 25km/h, above which it just stops providing assistance. But I would really like to go a little faster at times. I believe that the crank mounted motor detects the pedal force (me), and derives the speed from a magnet fixed to a spoke which passes a sensor on the rear wheel support. Here is my concept.
1). I move the magnet along the spoke away from the Bosch sensor
2). Add a new magnet detector and hook it to a picaxe
3). Have the Picaxe sense the passing magnet and simply repeat the same magnetic pulse to to Bosch sensor.
So so far nothing changes as far as the Bosch system is concerned. But now the trick.
4). When the speed reaches say 24km/h I halve (or fix) the speed sent to the Bosch sensor. Now the bike should think that it is travelling at 24km/h and provide motor assistance beyond the preset limit.
I think the approach is sound, but what I cannot decide on is how to provide a magnetic pulse from the Picaxe to the Bosch magnetic sensor. I would appreciate any thoughts. My first thought is to rob a 5V relay of its coil.
Anyway, its just a bit of fun. Illegal, I know......
My e-bike is a crank motor type (by Bosch) and provides various assist levels up to 25km/h, above which it just stops providing assistance. But I would really like to go a little faster at times. I believe that the crank mounted motor detects the pedal force (me), and derives the speed from a magnet fixed to a spoke which passes a sensor on the rear wheel support. Here is my concept.
1). I move the magnet along the spoke away from the Bosch sensor
2). Add a new magnet detector and hook it to a picaxe
3). Have the Picaxe sense the passing magnet and simply repeat the same magnetic pulse to to Bosch sensor.
So so far nothing changes as far as the Bosch system is concerned. But now the trick.
4). When the speed reaches say 24km/h I halve (or fix) the speed sent to the Bosch sensor. Now the bike should think that it is travelling at 24km/h and provide motor assistance beyond the preset limit.
I think the approach is sound, but what I cannot decide on is how to provide a magnetic pulse from the Picaxe to the Bosch magnetic sensor. I would appreciate any thoughts. My first thought is to rob a 5V relay of its coil.
Anyway, its just a bit of fun. Illegal, I know......