4 ms·

Nice work. I'm still clinging to my conventional bikes, but anticipate when something will eventually push me over the edge, such as old age or a long distance

Nice work. I'm still clinging to my conventional bikes, but anticipate when something will eventually push me over the edge, such as old age or a long distance commute. I've been reading whatever I can learn about e-bike technology so I'm ready. So far the simplest assist I can think of would be a front wheel hub motor and a switch that turns on a constant amount of torque. This would still let me control my speed by how hard I pedal. Of course I'm scratching my head over how I would control it, since it would probably not be an off the shelf controller. But I'm also fascinated by the electronics, and having to design my own controller would be a benefit, not a liability. I also have an obsession with knowing how things work, that I have to contend with. Of course all of this is until I think of something better.

derekp7 5y ago
For a controller, look at the Cycle Analyst from Grin Technologies. It is somewhat hackable, can hook up to a crank based torque sensor, or use a cadence sensor. Personally I just use a throttle that "remembers" a given setting when you hold it in a given position for a couple seconds, and throttle enough to bring me up to say 8 mph, then peddle to get to 15 or so. Basically I peddle about how hard I want to, then adjust the throttle to give me the speed I feel like going. But you can also do fully peddle-based (cadence or torque) assist to make it feel more natural (then it would be like riding with a strong wind at your back).
- analog31 5y ago
  Nice documentation at their site. Thanks for the tip!
gkasev 5y ago
Yes, I have a long commute to work (18km one way) and this was my main motivation for building the bike. On the controls side of thing, I have the ECU and an Arduino Nano. The Arduino uses the BEC port of the ECU as a voltage supply to run a simple routine translating the analog output (potentiometer) from the throttle handle to a PWM signal that the ECU can understand. The way that the assistance work is that while you are pedaling, you can turn the throttle and adjust until you get the assistance you want - pretty simple. After a while it becomes natural.
stinos 5y ago
So far the simplest assist I can think of would be a front wheel hub motor and a switch that turns on a constant amount of torque. The simplest: sure. However if you're used to cycling chances are you're not going to like that front wheel hub all too much. It feels weird overall (might depend on geomerty though) and has the tendency to slip on upwards sloped unless you do an effort of getting weight over the front. For my personal taste, hub in the backwheel feels the most natural.
johnwalkr 5y ago
Torque is related to current so it’s not difficult to control, at least if you’re building your own device from procured IC parts. Hobbyist motor controllers for drones etc probably don’t often have that feature however.

derekp7 5y ago

For a controller, look at the Cycle Analyst from Grin Technologies. It is somewhat hackable, can hook up to a crank based torque sensor, or use a cadence sensor. Personally I just use a throttle that "remembers" a given setting when you hold it in a given position for a couple seconds, and throttle enough to bring me up to say 8 mph, then peddle to get to 15 or so. Basically I peddle about how hard I want to, then adjust the throttle to give me the speed I feel like going. But you can also do fully peddle-based (cadence or torque) assist to make it feel more natural (then it would be like riding with a strong wind at your back).

analog31 5y ago
Nice documentation at their site. Thanks for the tip!

gkasev 5y ago

Yes, I have a long commute to work (18km one way) and this was my main motivation for building the bike. On the controls side of thing, I have the ECU and an Arduino Nano. The Arduino uses the BEC port of the ECU as a voltage supply to run a simple routine translating the analog output (potentiometer) from the throttle handle to a PWM signal that the ECU can understand. The way that the assistance work is that while you are pedaling, you can turn the throttle and adjust until you get the assistance you want - pretty simple. After a while it becomes natural.

stinos 5y ago

So far the simplest assist I can think of would be a front wheel hub motor and a switch that turns on a constant amount of torque. The simplest: sure. However if you're used to cycling chances are you're not going to like that front wheel hub all too much. It feels weird overall (might depend on geomerty though) and has the tendency to slip on upwards sloped unless you do an effort of getting weight over the front. For my personal taste, hub in the backwheel feels the most natural.

johnwalkr 5y ago

Torque is related to current so it’s not difficult to control, at least if you’re building your own device from procured IC parts. Hobbyist motor controllers for drones etc probably don’t often have that feature however.