Some of the motors are pretty small as it is. I am using a TSDZ2 and it is barely noticeable. Unless I tell someone, people generally don't notice it. What stands out is the batteries. I currently have them in a trunk bag, I am waiting for a triangle bag, that I have on order, to arrive.

It is a torque sensing motor, that means that I still need to pedal. I am still getting my heart rate up. However, the difference is that I am using it, instead of driving, to work and on errands. When leaving in the morning straight into a 23+ mph headwind, I definitely appreciate the assist.