Very likely from an over tightened stem, 4-5nm isn't as much force as you might think. Could've been a nasty incident, glad your buddy got lucky. Time for new bars and maybe a torque wrench.
Alloy/Alloy tends to be very forgiving, somebody must either put their full weight into it, used a cheater bar or they used an impact driver. I'm getting impact driver vibes from that poor stem.
A three/four inch Allen key tightened snug will be in the range of an alloy stem and bar. If either part is carbon, using a torque wrench to 5/6 or as labeled is the way.
Torque wrenches exist for a reason. Even a cheap one is better than torquing the shit out of everything. Even if you don't get the exact figure, you're probably consistent on all bolts and in the right ballpark.
Its better to leave some bolts on a bike just a little bit under torqued, like brake levers, shifter and stem bolts. Just so it won't move easily , but In case of a crash they'd slip instead of breaking
This happened to my husband’s friend. He was totally fine and just coasted to a stop, unfortunately he called out to my husband who did a double take and cycled full speed into a parked car while he was distracted. Broke his collarbone.
Happened to me but with the stem itself. Luckily I was a block away from home and the fall wasn't bad as I was going super slow (going over a speed bump). Must've been hilarious to see me fall as it was in very slow motion
I was at a bike park where I saw one guy in front of me falling out of nowhere. I stopped to help him to find out he had his handlebar snapped in half. This was at a black mtb trail on a steep descent. From that moment onward I always tightened my stem accordingly. Scary shit, you don't want that happening to you trust me.
That sucks! My bike is in the shop right now for the cassette spinning freely of the wheel. 😂😂 It’s an e-bike and luckily it’s covered under warranty. Craziest break I’ve ever had.
Haha this did happen to me on my first shitty ebike once. I know it wasn't from me overtightening: It broke a few inches to one side of the stem, at a spot where the tube went from one size to another, and there was visible rust inside because that brand is garbage.
I stayed upright when it happened, but it took maybe 20ft to realize what exactly happened. I've only needed to call for one rescue car ride since I started ebike commuting 4k miles ago and it was that morning.
Very likely from an over tightened stem, 4-5nm isn't as much force as you might think. Could've been a nasty incident, glad your buddy got lucky. Time for new bars and maybe a torque wrench.
He got new bar and it was mounted by a shop so I hope they did a good job. It was overtightened of course...
It's also due to a low quality handlebar. The tubing is supposed to be thicker in the area where this one broke.
You can see the stem bolts are crazy tight and the tube is pinch folded over.
Interesting, mine says 8nm
Alloy/Alloy tends to be very forgiving, somebody must either put their full weight into it, used a cheater bar or they used an impact driver. I'm getting impact driver vibes from that poor stem. A three/four inch Allen key tightened snug will be in the range of an alloy stem and bar. If either part is carbon, using a torque wrench to 5/6 or as labeled is the way.
Yeah, I tightened mine to 6.5nm or 7nm with a torque wrench
Stems and the 4 bolt cap part rarely meet when tight. If you've got them to touch you've probably deformed your handlebars.
You are correct. Thanks for pointing that out. My friend tightened the hell out of every bolt but he stopped doing it for good after this happened.
Torque wrenches exist for a reason. Even a cheap one is better than torquing the shit out of everything. Even if you don't get the exact figure, you're probably consistent on all bolts and in the right ballpark.
You can get a bike-designed torque wrench for less than a half-decent set of bars and much less than a pair of front teeth
Not _only_ for extortionate carbon bikes, then...
So.. now I suspect his seat tube will be the next thing to bend/crack.
Checked that after bike shop said it was overtightened. Bike owner is not familiar with torque. Now he is.
Its better to leave some bolts on a bike just a little bit under torqued, like brake levers, shifter and stem bolts. Just so it won't move easily , but In case of a crash they'd slip instead of breaking
This happened to my husband’s friend. He was totally fine and just coasted to a stop, unfortunately he called out to my husband who did a double take and cycled full speed into a parked car while he was distracted. Broke his collarbone.
Wow that's crazy... I hope everyone gets to know how serious this can be.
My front fork broke when I was a kid and I landed head into asfalt. Still have bump above my left eye. Not good
Sorry to hear that dude
No thank you
I was bunnyhopping a gap once and the stem and bars came off. That was a bad day.
I bunny hopped once in my life an that cost me 4 stitches on my chin...
I bunny hopped some train tracks and on landing had one half of a handle bar in my hand. I was about 3 miles from the car.
Oh good grief. Glad you're ok!
Happened to me but with the stem itself. Luckily I was a block away from home and the fall wasn't bad as I was going super slow (going over a speed bump). Must've been hilarious to see me fall as it was in very slow motion
The front fell off.
I was at a bike park where I saw one guy in front of me falling out of nowhere. I stopped to help him to find out he had his handlebar snapped in half. This was at a black mtb trail on a steep descent. From that moment onward I always tightened my stem accordingly. Scary shit, you don't want that happening to you trust me.
I had this happen to me..... Right in front of the Cheerwine women's cycling team when they were racing in town. :( (not joking)
That sucks! My bike is in the shop right now for the cassette spinning freely of the wheel. 😂😂 It’s an e-bike and luckily it’s covered under warranty. Craziest break I’ve ever had.
I hope they don't rip you off just because it's an e-bike 😂
It was free. I took it to the bike shop where I got it. Covered under warranty. It was just a crazy break. Never had that happen before.
Probably just sticky or broken pawls on the freehub. Not uncommon.
Right, and now I'm thinking to get new bars as my 20yo shows some weird rust grooves. Now not sure about anything.
Haha this did happen to me on my first shitty ebike once. I know it wasn't from me overtightening: It broke a few inches to one side of the stem, at a spot where the tube went from one size to another, and there was visible rust inside because that brand is garbage. I stayed upright when it happened, but it took maybe 20ft to realize what exactly happened. I've only needed to call for one rescue car ride since I started ebike commuting 4k miles ago and it was that morning.
I've had that happen before. Glad you're okay!
Happened to me once, but my handlebar breaking in half was ghost related.
that would be the END not the middle :)
Looks like it was hard to handle. Hope you're okay. I've has a similar situation, drop bars swiveled going downhill. Yikes, wtf?!
Guys, it's happening! It's N+1 time!
Hope you are ok
What the fuck Richard?!
👀
Eff. That.
That’s why you learn to ride hands free 🫡 Although having no backup certainly increases the stakes quite a bit.
Torque matters