We have Magnum classic ii low step folding bikes. They are supposed to have a range of 50 miles, it depends on how much "pedal assist" you want. More pedaling, more milage. They have 500W motors, very powerful. The "Pedal Assist" (PAS) goes from 1-6. We don't go higher than 3. Rarely above 2. They can be very fast if you want to push it all the way. Too much for us.
The folding feature allows them to be folded up and put in the back of the truck forward of the 5th wheel hitch and under the tonneau cover. I put a yoga mat in the truck bed to prevent paint rubbing/chaffing.
With battery removed, they are 55lbs each. Heavy but manageable. We really like the step through feature. Easy on/off without having to swing your leg over. Getting too old for that.
I would have preferred the fat tire bike for going on the beach or off road trails but so far we have not really done any of that so we don't miss that feature (and the additional weight of fat tire bikes - 75lbs).
As they are, the tires are good for off road packed gravel or packed dirt trails. Not so good on loose gravel or sand.
Overall we are very pleased with them.
If you get tired just turn up the PAS.
https://www.magnumbikes.com/product/...c-ii-low-step/