Understanding motor power ?

[Matt van]

Hi guys Im a bit confused at the ratings of the motors. the Bosch cx 4 has 85nm of torque is that always there in all levels or is it 50% 42.5nm of that on eco and upto 340% 289nm in turbo or how is it calculated? and the 250w "speed" is always constant?
TIA

 

[mtb-steve]

My understanding is - the 85nm is a maximum, the assist levels are related to the effort you put in, and the 250w is an average over a given time period.

 

[mike_kelly]

The 85nm is a measure of torque. How much can the motor do going uphill at heavy work load maximum. The 250w is the average power of the motor. You could have a motor that is 250w but geared for speed. So it can't climb a hill for Sh&t but can go really fast. You could also have a motor with high torque that can't go real fast and both could be 250w motors.
The 85nm is the maximum torque. The assist settings can be assigned in software for most motors but yes there will be less torque required for the same terrain at a lesser assist level.
The 250w is not "speed" but the maximum average power the motor will draw not counting any peak it is able to do for a short time.