Once again, match your needs with a bike that offers that. But, you need to look at the basics and that is the motor output, the battery voltage and amp hours.
There are a few categories that need attention:
- The frame: carbon or aluminum? Carbon is only used in the top of the range bikes. No real need otherwise. And it makes it very expensive.
- Groupset: Difficult one. Here you can spend a lot of money or maybe buy rubbish. Start by selecting a known brand such as Shimano.
- Motor: If you want to use public roads you cannot use a motor that exceeds 250W. So for use on off road private property or on a private estate it is a different story. This is in line with legislation in Europe. Today 250W is about the norm for road riding and 500W for off road riding.
Battery: the big issue here is the Amp hours (Ah). This is the indicator of how long you can expect the battery to last between charges. Unless you cover long distances, go up long steep hills, you’re on the heavy side and you used the motor extensively, a 10Ah motor should suffice. If you do some serious MTB maybe more.