Hey all,
I’m leading a team of mechanical engineering students building an ebike for a senior capstone project. I live in the pacific northwest (USA), and a recent survey found the top 5 barriers to bicycling in this area are:
1) The weather
2) Places I need to go are too far
3) The hilly terrain
4) I don’t feel safe
5) It’s difficult to carry things on my bike
We’re building a bike that I hope will address all of these issues: an electric-assist cargo bike with a rain cover and a full light system, complete with turn signals and brake lights. We’re going to design, perform FEA, and build our own carbon frame for it. I’m excited!
My biggest question is about the motor, and that’s why I’m posting today. We’re trying to stay at or below 40 lb (18 kgs) max weight, so we’ve narrowed down the motor to 2 options:
1) A small rear hub motor, likely the Cute Q100C.
2) A little (1-2 lb) RC motor geared down and assisting the human drivetrain.
These are both very lightweight and have the potential to meet our power requirements, which are:
“Can assist a total bike+rider+cargo bike weight of 350 lbs up a 10% grade at 6+ mph with 150 watts or less of human input for at least 60 seconds.”
I played with Grin’s ebike simulator (god I love that Justin et all put that together!), and it turns out that in theory the Cute motor can do it.
That said, I love the idea of getting 70%+ efficiency at any speed, and so I’m drawn to a mid-drive (driving bicycle's gears) system with an RC motor. Plus, we’re MEs, and so we’re not scared of gear reductions! But we know nothing about RC motors and controllers. I've spent a few hours sifting through this forum, and so I now understand the basics – what ESC, outrunner v inrunner, and kv mean - but I don't know enough to choose a motor. And most of the threads here are about higher-power setups.
So here’s my question:
What RC motor would you suggest we use to achieve our design goal, written above in quotations?
Why?
And what controller/battery would you pair with it? Is it possible to use a standard ebike controller, and so use standard ebike controls?
We need to decide soon, so your input is HUGELY appreciated! Thank you!
I’m leading a team of mechanical engineering students building an ebike for a senior capstone project. I live in the pacific northwest (USA), and a recent survey found the top 5 barriers to bicycling in this area are:
1) The weather
2) Places I need to go are too far
3) The hilly terrain
4) I don’t feel safe
5) It’s difficult to carry things on my bike
We’re building a bike that I hope will address all of these issues: an electric-assist cargo bike with a rain cover and a full light system, complete with turn signals and brake lights. We’re going to design, perform FEA, and build our own carbon frame for it. I’m excited!
My biggest question is about the motor, and that’s why I’m posting today. We’re trying to stay at or below 40 lb (18 kgs) max weight, so we’ve narrowed down the motor to 2 options:
1) A small rear hub motor, likely the Cute Q100C.
2) A little (1-2 lb) RC motor geared down and assisting the human drivetrain.
These are both very lightweight and have the potential to meet our power requirements, which are:
“Can assist a total bike+rider+cargo bike weight of 350 lbs up a 10% grade at 6+ mph with 150 watts or less of human input for at least 60 seconds.”
I played with Grin’s ebike simulator (god I love that Justin et all put that together!), and it turns out that in theory the Cute motor can do it.
That said, I love the idea of getting 70%+ efficiency at any speed, and so I’m drawn to a mid-drive (driving bicycle's gears) system with an RC motor. Plus, we’re MEs, and so we’re not scared of gear reductions! But we know nothing about RC motors and controllers. I've spent a few hours sifting through this forum, and so I now understand the basics – what ESC, outrunner v inrunner, and kv mean - but I don't know enough to choose a motor. And most of the threads here are about higher-power setups.
So here’s my question:
What RC motor would you suggest we use to achieve our design goal, written above in quotations?
Why?
And what controller/battery would you pair with it? Is it possible to use a standard ebike controller, and so use standard ebike controls?
We need to decide soon, so your input is HUGELY appreciated! Thank you!