- Mazovia, Poland
In such a situation -- in spite of you being in the lowest gear -- the bike slows down so much you cannot control it. The bike becomes wobbly, and the only thing to do is to stop. Restarting the ride up a serious climb from the cold start might turn to be impossible. (Similar happens when the motor is adequate but you cannot downshift more to maintain pedalling).What happens exactly when you try to climb but the motor is too weak?
Answering for Trevor:Can you help me understand those numbers? 11-42t and such. Sounds like the key to understanding gears, but I'm confused considering the first number doesn't change but the 11-46t one still helps with hills?
The gearing (gear ratio) is the number of teeth on the chainring divided by the number of teeth on the largest rear sprocket (a.k.a. "granny gear"). For serious climbing, the gear ratio in the granny would be the best less than 1. The front chainwheel in the Gazelle is 55T. According to the info from Trevor, the equivalent largest rear cog in the Enviolo is 42T. Divide 55/42 = 1.3. It is not only far from "mountain gearing" but also the 65 Nm motor is not what you need for your dramatic hills (too weak). Generally, IGH e-bikes are not made for steep hills, these are an urban thing.
I would like to draw your attention to two Specialized e-bikes. The special thing about them is the top version in each line (unfortunately, the most expensive one) comes with the Specialized 2.2 motor (90 Nm, 565 W peak motor mechanical power), which is adequate for your hills. The top of the line also comes with a big 710 Wh battery, so you do not need to be worried by the range. Let me start with the most expensive e-bike, which seems to perfectly fit your bill.
Turbo Tero X 6.0
The price of that SUV e-bike is very high (CAD 9,500) but it is a marvel. It is a Full Suspension fully equipped e-bike with a rack rated at 20 kg, having mountain-grade brakes, and the gear ratio of 0.76. The gearing for the granny gear here is 21.05 gear-inch (the true mountain MTB gearing). This e-bike is intended for both urban and off-road use, and I think that thing would climb your King Of Mountain easily, even with the cargo. You will need the frame size S, and you could probably order it via a good Specialized LBS of the area (I recommend looking for a Specialized owned store as they have a better access to the stock than mom & pop stores).
Turbo Vado 5.0 Step-Through
For the price of CAD6,500, you are getting an e-bike with the same powerful motor and big battery as Tero X 6.0 but with even sturdier rear rack rated for 27 kg, and with equally excellent componentry. There is a small issue with the gearing of that e-bike: It comes with a stock 48T chainring and the 42T granny sprocket. The gearing ratio is 1.14 or 31 gear-inch, which is not good for the mountains. However, Vado allows you replacing the chainring with a smaller one. For instance, using a 32T MTB chainring would have brought you at the gear ratio of 0.76 or 21 gear-inches (the same as for Tero X 6.0). Replacing a chainring is a simple operation and can be done by the shop (with appropriate shortening of the chain). A compatible 32T chainring is used on Specialized Turbo Levo (the flagship Specialized e-MTB), so I can see no issues here. Again, I am sure you need the size S, and I wrote about the Specialized LBS selection earlier.
I had a technical look at the Specialized Turbo Como 5.0 IGH. Unfortunately, that beautiful e-bike comes with the carbon belt/IGH, and even with the strong motor, the steed might not be adequate for you hills!