Are you obese? Motorcycle tubes and tires have load limits. I used to pop tubes left and right when I was over 100kg. Get a tube and tire that can support the weight of you and any passengers. The below chart is for tires. The article goes on to explain the difference between tube thickness. I think with the road conditions here you should get the thickest tube you can get your hands on regardless of your weight. https://www.chapmoto.com/blog/2018/07/20/motorcycle-tires-101-choosing-the-right-motorcycle-tire/ Having a suspension that cannot support your weight will only make the situation worse.
This happens only with 1 particular motorcycle. Honda xr150. I have 2 honda 125. That carry much heavier loads, never happens. Load bearing B 551lbs. Nothing near that much ever on it. Made in China!!!
How does your 125 carry much heavier loads? Next time it happens pull the rim off and check for defects on the spokes and rims. If it continued to happen for one of my bikes I would switch to a rim capable of handling a tubeless tire. I personally won't even bother with any rim that requires tubes. The infrastructure here is just too shite for that cheap nonsense.
usually the cause of a ripped off valve stem is the tire rotating on the rim due to too little tire pressure. That can be caused by a leak, or maybe youre just not running with enough air in it? I wouldnt go below 18 PSI without a rim lock (which is a piece of hardware that prevents the tire from rotating on the rim). But I'm also just 75kg. Higher load -> higher minimum tire pressure. Also make sure youre running the right size of tube for your wheels and tires - an overstretched tube that isnt made for the volume it has to fill will break down quickly. I had that experience once after some idiot at drei bikes in cebu city mounted a way too tiny tube with the new rear tire I bought from them - I didnt make it off the island with that. Since then I do that stuff myself... Probably theres really something wrong with the rim, also check and probably replace the rubber tape that runs along the rim covering the spokes. getting tubeless rims for an xr150 will either convert it to a supermoto (well, kind of...) if you go for 17" alloy rims (though i doubt you find some that fit here very easily), or exceed the value of the bike if you try to find 21/18" tubeless (spoked) rims. There are ways to convert spoked wheels to tubeless yourself, basically by sealing the holes where the spokes are mounted, but that may or may not work depending on many factors. generally, spoked wheels are superior on shitty streets, since theyre near indestructible. a flat can be fixed, a broken rim, not so much. theres a reason why enduro bikes run on spoked wheels, and it's not cost savings
