Yes, it is heavily depending on smooth track surfaces such as tarmac, asphalt etc, it is not for MBT biking in the woods. And you must spend more caution on looking ahead and check small obstacles on the surface that a normal bike rider woudl not need to care for, but that is not different to the e-scooters that you now can lease in so many cities.
I expect in the beginning I will wag my tail like a walking duck when stand-riding this and get plenty of laughter.
The point is that you do not sit that much on it, but stand: not more than 50% of body weight should rest on the saddle, with normal bikes it is much more. Since you stand almost straight and upright, it is less your muscles pushing the pedals, but your own body weight: as if you ride a normal bike and at a hill lift from the saddle and "stand" in the paddles. Also, the dynamic swinging of the spine, back, shoulders, it is very different than on a normal bike, and more flexible, dynamical.
It is this altered movement pattern hat made me curious, and I imagine it can be great fun.
They claim that you can drive as fast with it as with a normal city or touring bike, speeds of up to 35 km/h they say are absolutely in reach of evberybody, and at hills you may find you reach the top like the others, and as fast: but much less exhausted and breathing not as heavy. The top speeds they measured, was around 60 km/h. Well, I am not eager to try
that. Not at all. These days I start to feel alarmed when speeds start to scratch at the 40 km/h mark.
They also did long range multi-day tours and said it is absolutely capable to do that: and even less stressful to body and muscles.
They also claim their materials are such that the wear and tear on this is less than on other bikes, and there is less material degeneration in the chain, sprockets and so forth. Since the sprockets have so few teeth and thus are under big stress, that is surprising, but for the time being I trust their words.
I was thinking occasionally on getting a folding bike as a third bike, but never really "needed" it. This I get now only due to the very different movement body position and movement - I got curious.
And the lightest version weighs only 8.5 kg, although made of flexible special steel!
The whole frame they say is designed to be a spring, being flexible, and very much so. The tyres limit the carry weight, not the frame. The frame is safe to not break at up to 250+ kg load. Its the tyres limiting it to something much less, 100 kg in total.
They work on a version with bigger tyres.
I will post when I got it. Could take 10-14 days, they say.