How does this motor work in the real world?

PlanBee

New Member
Region
United Kingdom
Recent owner of an Orbea Vibe with a X35+ Motor.

I read somwhere that for a constant assist level, the amount of power you get is depends on speed of the cassette relative to the hub.

That means as long as the cassette is spinning at the same rate as the hub then I will get 100% of the available power (given a constant assist level and the motor map) Is that correct?

It doesnt matter what my pedal cadence is, so I'll get the same power from the motor in top gear as well as bottom gear. Is that correct?
 

retiredNH

Well-Known Member
Region
USA
The cassette and hub will always turn at the same speed (technically, RPM) since they're fixed together. The crank speed (RPM) will vary with the gear chosen. Since the motor is connected directly to the wheel, the gear you choose has nothing to do with the power the motor delivers to the wheel. Power from the motor is a whole different topic, but not really relevant to what you're asking. You should probably think about torque, which is what makes the wheel turn, and makes it easier for you to pedal!
 

PlanBee

New Member
Region
United Kingdom
Thanks for the reply. If you free wheel then the cassette does rotate at a different speed, but I take your point generally.

So what determines the amoint of torque/power that the motor puts out, what is it in proportion to?
 

retiredNH

Well-Known Member
Region
USA
Thanks for the reply. If you free wheel then the cassette does rotate at a different speed, but I take your point generally.

So what determines the amoint of torque/power that the motor puts out, what is it in proportion to?
But when you free wheel, all the power is from the motor, so my point stands...

The torque and power of the motor depend on a lot of factors, such as the voltage going to the motor, the rotational speed of the motor, current rating of the controller, battery maximum output current and the design of the motor. There's no simple answer. It's part of the reason why hub motor performance varies so widely. Then there's the issue you didn't even ask, efficiency...
 

PlanBee

New Member
Region
United Kingdom
Thanks for your answers, maybe I need to ask the questions in the Orbea Vibe forum.

BTW not worried about efficiency