Catastrophic bicycle failures

[GirishH]

As some of you know, I bought a new bicycle that failed catastrophically within 3 days..

​The gears were slipping and skipping right from day zero. It’s a 3 x 8 setup, and the shop mechanic claimed the manufacturer had mistakenly installed a 7-speed rear derailleur instead of an 8-speed. Whether that's true or not, he eventually swapped it out for a new 8-speed derailleur after my complaints.

​After that, the bike rode fine for three days—maybe 150 to 200 km.
   

​Then, on day four while riding through flat terrain, the shifting went haywire: a single lever push would suddenly jump 3 to 4 gears at a time. Within 15 to 20 minutes, I heard something fly off the rear of the bike. I looked back and saw the chain had snapped and wrapped tightly around the cassette, while the rear derailleur had completely sheared off and was lying on the road.
   

   

​The mechanic insists I must have crashed the bike or hit it against something. That’s entirely untrue—there isn't a single scratch on the frame or anywhere else.

​I'm currently fighting the manufacturer over this, but I'm trying to figure out what technically caused such a catastrophic failure.

[Sidewinder]

Sorry to hear all that... and it's why good equipment is so important to me. I gotta admit, when I read your thread title, I envisioned something else, lol. Lemme tell y'all a short story concerning "catastrophic failure" back in the day...

During my "high school daze" my friends & I were all into skateboarding and BMX, so when the school maintenance crew left a large pile of dirt on one playing field, we built an impromptu jump out of the pile, right? Took turns flying off the jump and landing out in the grass, or on the far side of the jump. Well, some neighborhood kids showed up to check out the action, and one kid had a girl's bike with 20" wheels, a rickety piece o' junk complete with tall bars, banana seat, etc. Thing looked like it had been neglected since the day of purchase...

This friend of mine commandeered the bike to show us all how it was done, and he pedaled like mad from a good distance prior to launching off the dirt pile! He gave a mighty heave on the cheesy wannabe ape hanger bars, and that's when things went south, lol. The bars & neck came out of the forks, the headset (which was already heller loose) disintegrated, and the front wheel and forks dropped out of the bike in midair, all during a spectacular Guinness World Record launch off the jump!

Picture my friend sailing through the air, pulling a classic 'Flying W' with the bars and neck still in his hands, the front wheel and forks dropping away to bounce on the turf and roll away, lol... the rest of the piece o' junk bike dropped away like a rocket stage below him, aye? The whole scene reminded me of one of those video clips of a rocket launch, where a stage falls back to Earth and the rocket itself keeps soaring, lol. Funniest jump I've ever seen in my life, hands down! My friend was unhurt after landing in the grass, the rest of us were rolling with laughter!

Now, THAT was a CATASTROPHIC FAILURE, lol. We pieced the bike back together enough for the kid to roll it home, and henceforth my friend stuck to catching air on his own BMX bike... his effort to impress us by jumping the piece o' junk bike was his undoing, lol. To this day, I don't know how the bike didn't fall apart BEFORE my friend commandeered it, lol. All of our BMX bikes were totally solid, dirt-worthy machines, but my friend just HAD to jump the POS! What's that saying? "PRIDE GOETH BEFORE A FALL!" Lol... and ain't THAT the truth?

Oh, well, at least nobody was hurt, which was the most important thing! And to this day, that 'Flying W' my friend pulled has been unmatched! He must have been 6' in the air when the POS bike disintegrated, the mighty heave on the bars just initiated the disintegration, lol. And the goofy banana seat added that special touch as the bike fell away... my friend was lucky he didn't land on that thing and rack his... well... you know, lol. The final landing could've been MUCH WORSE! But he always was a lucky b@stard, lol.

Meh, as 'The Bard' says: "ALL'S WELL THAT ENDS WELL!!!" Better than going to the ER with multiple fractures, contusions, etc! But that was a GLORIOUS JUMP, and NO LIE! The only way my friend could've improved upon it was if he pulled a "tabletop cross-up" as the bike fell apart, lol. However, his 'Flying W' was quite STYLISH and IMPRESSIVE, and the rest of us got a good laugh out of it, yeah? Ah, the good ol' days... those halcyon days of our youth when we did some CRAZY $H!T, lol. Sometimes, I miss those days!

[Flowrider]

Definitely feels like unnecessary drama on your adventure.
Where's MisterGordo?
When will you have it back to ride?

[froze]

I've been riding for over 50 years and never had a claustrophobic, fine, catastrophic failure. What it looks like happened is that the chain had a stiff link or two from the factory, and it just blew when it got into the derailleur the wrong way, might have been the angle of the chain in a different gear than what you had been using for those previous days that set the chain reaction off, and ripped off the derailleur and wrapped the chain. BUT, I'm just guessing, but that guess comes from someone a few years ago bought a bike from Bikes Direct and that exact same thing happened, and the bike shop he took it into determined that's what happened, and Bikes Direct had to send him a new chain and rear derailleur, but he had to pay the labor. So that's where My guess comes from.

[GirishH]

@froze, thanks for your firsthand experience and input—I had an inkling the chain had somehow ripped the derailleur out.

​In all my years of riding, this had never happened, and it genuinely scared me. It was especially terrifying being so far from civilization and any bike shop, knowing that none of the spares I carried would have helped me fix it.

​At the same time, I’m glad it happened in the best possible place and time. I was in the Himalayan plains—still around 10,000 feet, but flat. Because it was afternoon, I had the advantage of warmth, which kept my mind and fingers working (the cold really gets to me).

​Given the circumstances, I managed to figure out a way to stash the bike and continue exploring the Himalayas.

​I’m still fighting with the manufacturer and the shop to sort this whole mess out.

(10-06-2026, 04:58 PM)froze Wrote:  I've been riding for over 50 years and never had a claustrophobic, fine, catastrophic failure. What it looks like happened is that the chain had a stiff link or two from the factory, and it just blew when it got into the derailleur the wrong way, might have been the angle of the chain in a different gear than what you had been using for those previous days that set the chain reaction off, and ripped off the derailleur and wrapped the chain. BUT, I'm just guessing, but that guess comes from someone a few years ago bought a bike from Bikes Direct and that exact same thing happened, and the bike shop he took it into determined that's what happened, and Bikes Direct had to send him a new chain and rear derailleur, but he had to pay the labor. So that's where My guess comes from.

[GirishH]

@Flowrider, MisterGordo is still in Nepal..I am hoping to reunite with it in about 2-3 weeks and then hopefully ride it back to South India. Keeping fingers crossed...:-)

(10-02-2026, 11:08 PM)Flowrider Wrote:  Definitely feels like unnecessary drama on your adventure.
Where's MisterGordo?
When will you have it back to ride?

[Flowrider]

Fingers crossed 🤞🏻 Not that you needed it, but it'll give an even greater appreciation of MisterGordo's value!

[GirishH]

Fingers crossed!

After my "new" bicycle broke down in Ladakh, I walked everywhere. Along the way, I met a fellow cycling enthusiast who is also planning to tackle the Thorong La Pass in Nepal.

I’ve always dreamed of taking MisterGordo up that famous pass one more time. So, if I don't ride him down to South India, I might let my new friend ride MisterGordo up the pass instead—if he's up for it.

After all, bikes are meant to be ridden, whether by me or someone else!

(10-09-2026, 12:58 AM)Flowrider Wrote:  Fingers crossed 🤞🏻 Not that you needed it, but it'll give an even greater appreciation of MisterGordo's value!

[Zviedrs]

Ah noo, such a bad luck!
I hope you'll have it figured out soon - fingers crossed!

I had a (bit) similar bicycle failure >10 years ago after a student party. Jumped on a (my friend's) bike, did some 100m and suddenly the rear derailleur crashed into spokes. Basically, the derailleur hanger failed out of nowhere, but at that time I was suspicious that another bike damaged it (eg. while its owner was parking the bike) enough to make the hanger vulnerable. The rim looked bad - 1/4 of the spokes had to be changed, I believe. There was issue with finding a replacement hanger and overall it was a painful case. Can't remember how he had it solved.

[Flowrider]

In terms of wear and tear apparently your derailleur reacts to your riding cadence.

As I've been told, it goes something like this.

On hills or rough terrain, if you pedal fast like you're sprinting, it puts less strain on your derailleur, chain, and cassette.

Hopefully that makes sense...