I had previously put an electric-assist kit on my Trek hybrid, which I enjoyed for a couple of years. Then it kept working its way loose. This was a “mid-drive” kit, with the motor located where the cranks are. I could tell it was in danger of damaging my bike frame, so I took it off. I was able to reuse the battery from that kit and get an electric-assist rear wheel kit for my recumbent. A downside of a rear-wheel kit is that you lose a couple of gears because the motor takes up some of the available width. So my bike had nine gears in the back and now has seven. This is not a problem because the missing two gears were for climbing, and now I have assist for that.
I’ve had this set up for a couple of weeks and love it. It really extends my range. For example, last Sunday’s 60-mile ride would have been doable, but I would have been pretty tired after. It was a breeze with the assist. Plus it is fun to cruise at a faster speed, it’s really easy to go 20 mph for long periods. My heart rate monitor tells me I’m still getting a great workout.
There is one other feature that is especially useful on a recumbent. This kit has a thumb throttle so I can get assist from a standing start. Starting out is awkward on a recumbent. You have to leave one foot on the ground, push off with the other to get going, and quickly pick up the second foot to get it on the other pedal. This can be wobbly, and almost impossible to do if you have to stop while going uphill. Now I can just get going with the assist. Problem solved.
There are pros and cons of hub motors vs. mid-drive motors. The latter are able to take advantage of your gears, because they work through the cranks. This should make them better at climbing, but I can climb just as well with my hub set up on the recumbent as I could with the mid-drive on my Trek. I mentioned how you can lose a couple of gears with the hub motor. But I still have my triple chainring up front, so I have a 21 speed bike. With a mid-drive motor, you typically only have one chainring, so I would have ended up with a 9 speed. Finally, fixing flats is harder with a hub motor. There is a hefty nut to unscrew instead of a quick release to get the wheel out. Because of this, I put a Scwhalbe “marathon plus” tire on that wheel, which has really good flat protection. I also put a thorn-proof tube, for “belt and suspenders” protection.
You can save quite a bit by adding an electric-assist kit to a bike, rather than buying a bike with factory electric-assist. That is especially true for recumbents. An equivalent setup to mine would have cost around US $8000. I got the kit for $500 (If I’d had to get a battery with it, I’d have paid about $500 more, but I was able to reuse a battery). And I got the bike used for $1500. The disadvantage is that you are on your own installing the kit and working on it if anything goes wrong, unless there is an installer you can hire in your area. Local bike shops usually don’t want to work on electric-assist set-ups that they don’t sell themselves.