Very happy with my new ebike!

I bought two bicycle few months ago. Work well. We like it. Perfect for small trips in the city or around the city.

Pros:
The bike itself is beautiful. Aesthetically, it looks very modern and stylish. It is also not as heavy as many other e-bikes. Even though it does not have suspension, it still handles bumps and uneven roads surprisingly well and does not feel too harsh to ride. The frame and materials feel solid and robust.
Charging the battery is very convenient since you can either charge it while attached to the bike or remove it easily. The packaging was excellent, and the bike arrived almost completely assembled. It is an excellent option for short urban distances.
For the price, this is a good budget e-bike and you definitely get decent value for the money. However, after using it, I realized that next time I would pay more attention to certain details and probably spend a little more for a more refined experience. Still, this bike deserves credit for what it offers at this price point.

Conts:
Although the folding mechanism itself is easy and practical, the bike lacks any kind of proper support system when folded. The folding design seems intended mainly for transporting the bike inside a car or storing it temporarily, but not for keeping it folded upright at home. Once folded, the bike is unstable and does not stand well on its own.
An additional support leg or integrated folding stand would have been a huge improvement and would make daily use much more comfortable.
Another issue is that some important moving parts arrive almost completely dry from the factory, especially the main folding mechanism. There should definitely be instructions recommending lubrication or oiling certain parts before regular use.
Battery:
The advertised battery range is far from realistic. The only way I can imagine achieving 70 km is by riding almost entirely without assistance, which defeats the purpose of owning an e-bike.
Using maximum assistance continuously, the battery lasts around 16 km in real conditions. I live in Berlin, which is mostly flat, so I imagine the range could become even more problematic in cities with hills or slopes.
Speed / PAS Levels:
This is closely related to the battery issue. The bike has only three assistance levels:
PAS 1 = 10 km/h
PAS 2 = 15 km/h
PAS 3 = 25 km/h
To give some context, pedaling this bike without assistance and with almost no effort already gives you around 8–11 km/h. Because of that, the first assistance mode feels almost pointless — it is simply too slow to be practical.
The second mode at 15 km/h should honestly have been the first assistance level. Even then, the difference between 10 km/h and 15 km/h is not very significant.
Another important detail is that these assistance levels behave like fixed speed modes. This means you cannot comfortably maintain intermediate assisted speeds such as 18 km/h or 20 km/h. The bike essentially locks you into riding at either 10 km/h, 15 km/h, or 25 km/h depending on the selected PAS level.
Because of this, daily riding can feel awkward: you are either going too slow or suddenly much faster, with no comfortable middle ground in between.
The real problem is the huge jump from 15 km/h directly to 25 km/h. A 10 km/h difference is very noticeable in daily riding. It would have been much more practical to include an intermediate mode around 18–20 km/h.
Something like:
PAS 1 = 15 km/h
PAS 2 = 20 km/h
PAS 3 = 25 km/h
would make far more sense for urban riding.
Right now, it honestly feels like the bike only has two usable speeds: 15 km/h and 25 km/h.
If the company released an update improving the PAS speed distribution — which in my opinion is the bike’s weakest point — I could recommend this bike without hesitation.
But as long as it only offers these three assistance levels, with one of them being almost useless in practice, I cannot fully recommend it. At the moment, you are either riding too slowly or too fast, with nothing comfortable in between.

A few things I personally think could improve the BK35S:

* The standard saddle is not very comfortable for longer rides. A softer saddle or suspension seatpost option would improve comfort a lot.
* The seatpost tolerance feels very tight. Adjusting the saddle height can sometimes scrape the post.
* Quality control before shipping could be checked more carefully, especially around sensor connections and packaging damage.
* Including clearer instructions for sensor troubleshooting would help many customers.

What I really appreciate:

* Lightweight and easy to carry
* Stable ride despite compact wheels
* Smooth folding mechanism
* Comfortable geometry for city riding
* Stylish minimalist design
* Very fun bike once properly set up
* Excellent value for the money

So my honest conclusion is:
The BK35S is a fantastic urban mini e-bike with a great concept and surprisingly good ride quality, but quality control and some comfort details still need refinement. Once working correctly, it honestly feels much more premium than its price suggests.

I have had an electric bike for many years. It's a big heavy full size one that I can no longer lift at 80 tears old. The old one has a throttle . It's taking a bit of getting used to not having a throttle as I found that easier to control my speed, but I am sure that I will get used to it using the 3 selectable speed. A security key on the controller would improve it against theft. Key to be turned on before it will start. When turned off, shorting out the motor so that it would be very hard to pedal away.