I just saw a YT video of a motorized trailer designed to push the bicycle and it seems very unsafe to me. I saw 2 of them, but the one I though was REALLY bad was the RideKick motorized e-trailer.
It seems to me that this thing has some really bad design features. For one, it is only attaching to one side of the bike on the axle. Unless you have vertical dropouts, especially with QR, that it could dislodge your wheel or make it not straight.
The other thing, which I think is much worse is the upward push along with turns. Should you hit the throttle on a turn, particularly a sharp turn, this thing is going to try to go straight forwards. This thing could easily end up at a 45 degree angle from the bike or even more and with all of that upward and now lateral force, could knock you over. Even if it doesn't jack-knife on you, what will all that lateral force on the bike do to your rims over time?
It is attached at a low point, well below most of your mass and so I am not entirely sure of just how safe/dangerous this really is in that respect. The low attachment point could make safer than it looks.
There's also no automatic cutoff and so with a panic stop you have up to 60 lbs with a second battery or possibly just another 20 pounds of "stuff" (which is a significant fraction of the average rider's weight, more than 1/3) pushing on the back of the bike, possible with the motor going. It will also help to lift the back wheel off the ground since the pushing has upward force as well, again far worse if you haven't full disengaged the throttle (and this setup has no way of automatically killing the engine on braking).
Am I right in thinking this thing has no business being attached to anything but a 3 wheeled trike? It just seems to me that everything is working against it. I am not trying to pick on RideKick, I just think the whole concept of pushing the bike from behind with a swiveling trailer is a bad idea.
Any feedback would be appreciated.