Chainset upgrade for Voltbike Yukon

I purchased a pre-made ebike to get started however now I'm feeling the need to customize! (and I'm a little clueless)

I bought this: http://www.voltbike.ca/voltbike-yukon-750-limited-2018.html and it's great EXCEPT that the gearing sucks. It only has 7 gears and when I'm going past 20km/h with the motor, it feels like I'm not contributing when I pedal.

Hence, I'm thinking that upgrading my main chainset crank (is that he right term? The BIG crank) would fix all my issues.

However:
1. I don't know what to get.
2. I know there are sensors near the crank, what do I have to do differently because of them?
3. Is this even possible?

I'd like to be able to pedal and contribute to the effort when I'm going 32km/h+

Many chainrings simply bolt to the crank spider, so you can measure the BCD (bolt circle diameter) of your largest chainring and get one with more teeth to enable faster pedalling speeds.

You can use the ratio of the speed you want vs the speed you get now, times the number of teeth on your existing largest chainring, to determine the number of teeth your new chainring has to have.

The problem most people have with going to larger chainrings is they don't clear the chainstays or other parts of the frame.

Going to a wider BB axle (what the cranks bolt to) might fix that, but it'll make it harder to pedal (bowleggedness; Q-factor). Whether that affects you or not you'd have to test.

The other option is to change to a smaller outer sprocket (cog) on the rear cluster. You just don't want to use the smallest one all the time, as it will wear it (and your chain) out faster than if you shift normally up and down. (lots of people stop shifting once they are using a motor)

Thank you! Great explanation.

So basically, just getting a chainring with more teeth and make sure it's compatible with my current crank spider?

I only have 7 speeds (and I'm always on the highest one) so I'm not sure replacing the rear cog (and that's the wheel with the motor, I fear it would be more complicated!) would work.