Bikers from the “Velomania” forum conducted a hellish experiment on themselves – they bought an Auchanbike and rode it in a sporty style for a certain number of kilometers.
If you didn't know, an Auchanbike, aka a wank-o-scope, aka a pile of scrap metal, is what is sold in supermarkets under the guise of a “mountain bike”. Here it costs around 60 Ls, and by analogy should probably be called a “Maximabike”. Buying this is dangerous not only for your health, but also for your wallet – because IT breaks down all the time. But it's good for athletic training – because the bike absolutely refuses to roll, you have to strain with all your might all the time. The main thing is not to get a hernia, hehe.
Quotes:
It became clear right away that the stock pedals spin poorly, one might even say -- they don't spin at all.
The brake discs were smeared with oil. The brakes wouldn't brake. The seat post wouldn't stay fixed -- it kept sliding down.
And then our strength ran out, and a total bummer began. Somewhere along the way we lost the front fender, and then tore off the rear one too, after which we arranged a test of the bike in the deep shit.
In that muddy puddle, which with a small run-up can be passed on any normal bike, the speed of the Auchanbike dropped to almost zero -- it was absolutely impossible to pull this dumb brute out of the bog. We prudently decided not to ride into the mud anymore and drove on, but there was no strength left to ride the Auchan 
We turned off the gravel road, rode out onto the asphalt, and at some point reached a long, dragging uphill. Sashka declared that he wouldn't make it up this climb, but he did anyway. Physical training shows.
Near the Silikatnaya station, where we decided to finish the ride, Sashka dropped the bike very unluckily. The left brake lever cracked (and then broke off entirely), and the handlebars flew out of the stem.
At some point it turned out that the right grip shift wasn't shifting and the bottom bracket axle was bent -- the crank arm was hitting the chainstay.
The rain caught us only on the way back. We got soaked to the bone, of course, but compared to the Auchanbike's unrollability, it was nonsense.
When a biker of an outright racing mindset and corresponding training rides twice as slow on asphalt as a chronic Sunday rider...
You should have seen Alexander's face when at the next stop he said "I'm not riding any further".
The design flaws of the Auchanbike are primarily its weight, very poor stiffness, ugly hubs, and the super-heavy, non-rolling plasticine wheels, and only then the transmission.
Oh yeah, totally forgot to say. The rear wheel stood crooked. Not in a plane parallel to the frame, but at an angle to it.
The main thing is that it doesn't roll and breaks easily.
I'll venture to guess that any Soviet bike would have ridden better than this shoddy creation. Any modern cheap roadster -- too.
Friends, you forgot to say that we bought an expensive Auchan-bike. How much did it cost again? 4300 rubles? (86 lats – Vladekk's note) I consider this cheating We should have bought one for no more than three.
This is what this miracle called “Challenger” looks like
For comparison – my bicycle weighs 14 kg.
In biker slang, this is called “shit-clay”
Of course, the test was run by biased semi-pros, so one can always say that things aren't really that dire. Nevertheless, don't say you weren't warned – a “mountain” bike under $400 is a fiction. If you're completely broke, buy a simple and reliable one with a minimum number of gears and normal frame geometry, meaning something similar to the Soviet “Tourist”. Or better yet, just buy a used one of those.