I am trying to understand if the problem I've got falls into a common problem for freewheel hubs. After googling and reading, I am still not sure if there is only this factor to what has happened.
I've done less than 200km on the "hybrid" bike I've got less than two months ago. I can't say I've abused it. I don't feel like it :) Mostly on asphalt occasionally a unpaved road but nothing dramatic like jumping curbs or riding over tree roots. A few days back we went to have a 30ish km ride and I've started to hear this clicking/clunking noise with vibration and sometimes with that feeling of the rear wheel moving sideways. From the 80-90s, when I was a kid and bikes were built differently, this usually meant you have a mess in the hub's bearings. Rightly so, when I came back home and removed the wheel, I've discovered the axle is bent
This is a Shimano MF-TZ21-CP 7 gears set that appears to be a very cheap one. I wish I knew earlier I have to check this too. I think the hub is equally cheap.
Now, I have no idea if this is a "very bent" or "slightly bent" much less I know of what is the cause of what, bent axle munches on bearings or munched bearings bend the axles?
I am reading a lot of people saying the core problem is the "leverage" a freewheel hub creates on the axle and that a heavier weighted rider should expect it to bend or break sooner. I weight 100kgs (220lbs), is it that much for less than 200km "leisure" rides? I mean, am I supposed to buy a box of axle kits to change every 100km?
Update after visiting the shop at May 8th:
So I went to the seller's shop, and left the bike there. As expected, they "didn't have time" to check the damage and quote the work while I was there. Though they told me right away that I "got into a pothole" which I am sure I didn't. At least not a pothole I would consider any danger for any type of bicycle.
So I've told them I didn't and left. Next day the shop owner calls me and says to come and pick up the bike. I ask her if and how much I'll have to pay to which she answers "come here, we'll explain". My favorite. They claim it is impossible to get into a defective axle, and it is impossible it was bent without being "hit". I keep insisting I've treated it properly and didn't ever jump a curb or got into a pothole. They give up with that look of offended honesty to which I say that I am not going to rob them over it and I am not going broke by paying an hour of work and a 150mm steel rod. She says that she is going to be fine too without me paying. I try to explain that it is not a question of paying, but of the service they offer, and that I need to understand if I have to sell the bike right now to avoid repairing it all the time, or it is just a matter of bad luck. And she doesn't take it well either, saying that she only sells good bikes and not department store junk and nobody ever came back with this bike and blah. So I take the bike and go home. Seems like going back there with any other problem is not the best option now.
TL;DR: Got the axle replaced "on warranty" with some good Shimano 9mm (as they said). Seller wasn't happy about it and I am not convinced it is not going to happen again.