My friends rear derailleur suddenly got caught in the spokes while riding on a relatively flat path. What could be a potential cause for this happening?
I wonder if a spoke popped and got picked up by the derailleur/chain and pulled the whole lot up and over….
Newbosterone on
Derailleurs have a death wish. If they can take you with them, so much the better.
originaljfkjr on
You’ve got the beans above the frank.
spannerspinner on
It could be a number of things. Badly set up limit screws (low limit screw was too loose), an already bent derailleur (common if the bike has been crashed, or had a bump), spoke broke and caught the derailleur.
I’d guess the first one, maybe second. It’s an entry level bike, unfortunately these are often assembled poorly. Leading to issues like this.
maethib on
Been there. In my case it was the lower limit screw that was not right, so the derailleur was able to move into the spokes when in the lowest gear.
A friend of mine had this, when a stick got caught in tge spokes and then yanked the derailleur into the spokes.
Powerful-Scratch-107 on
Bent hanger, cage bent inwards, gears not set up properly etc.
Hugo99001 on
As usual, every information needed is not on the image and wasn’t given.
Did this happen while trying to go big-big (and the chain was too short – but why would you do that, especially on flat terrain?)?
Did this happen without actually switching gears?
What gear were you in?
What exactly happened (which part failed) – photo?
Great-Sandwich1466 on
Bent hanger or poorly adjusted limit screw. Maybe both
Hot_Leg_7534 on
Limit screws incorrectly adjusted, or the derailleur hanger was bent
SiRocket on
My first “real” mountain bike was a Jeep bike, and one day (after several years of riding it) as I was setting up for a jump it did the same thing. It wasn’t a spoke issue, mine had none damaged. After the crash I replaced only the derailleur and rode it for years after, always slightly nervous. I never did figure out what caused it.
qduffy on
Your freewheel/freehub also could have bound up. If you can’t coast all of a sudden, that could pull your drivetrain around pretty hard too.
lol_camis on
Most likely the derailuer was allowed to come too close to the spokes. And when your friend went over a bump or something, things flexed a little, and disaster struck
Afraid-Apple-5966 on
I would have thought that the plastic spoke protector would have stopped the derailleur moving into the spokes, even if the limit screws was slightly loose. I reckon either the derailleur was a bit bent beforehand, or something like a stick has got caught between it and the spokes.
TheDaysComeAndGone on
Could be:
* Object caught in the chain/derailleur (e.g. tree branch, or maybe even a broken spoke)
* Incorrectly adjusted limit screw (would require you to shift to the largest sprocket and beyond)
* Bent derailleur hanger which resulted in the same thing as the above (but you’d notice because shifting would be all wonky)
* Edit: Loose derailleur bolt would also have the same effect as the above (but again, you’d notice because shifting would be wonky)
* Stuck freewheeling mechanism in the rear hub (you’d probably notice problems with the freewheel mechanism before and as far as I’m aware they usually fail in the opposite way i.e. fail to engage)
If you didn’t notice any strange behaviour or noises before and shifting worked flawlessly than the first point is probably what happened.
15 Comments
I wonder if a spoke popped and got picked up by the derailleur/chain and pulled the whole lot up and over….
Derailleurs have a death wish. If they can take you with them, so much the better.
You’ve got the beans above the frank.
It could be a number of things. Badly set up limit screws (low limit screw was too loose), an already bent derailleur (common if the bike has been crashed, or had a bump), spoke broke and caught the derailleur.
I’d guess the first one, maybe second. It’s an entry level bike, unfortunately these are often assembled poorly. Leading to issues like this.
Been there. In my case it was the lower limit screw that was not right, so the derailleur was able to move into the spokes when in the lowest gear.
A friend of mine had this, when a stick got caught in tge spokes and then yanked the derailleur into the spokes.
Bent hanger, cage bent inwards, gears not set up properly etc.
As usual, every information needed is not on the image and wasn’t given.
Did this happen while trying to go big-big (and the chain was too short – but why would you do that, especially on flat terrain?)?
Did this happen without actually switching gears?
What gear were you in?
What exactly happened (which part failed) – photo?
Bent hanger or poorly adjusted limit screw. Maybe both
Limit screws incorrectly adjusted, or the derailleur hanger was bent
My first “real” mountain bike was a Jeep bike, and one day (after several years of riding it) as I was setting up for a jump it did the same thing. It wasn’t a spoke issue, mine had none damaged. After the crash I replaced only the derailleur and rode it for years after, always slightly nervous. I never did figure out what caused it.
Your freewheel/freehub also could have bound up. If you can’t coast all of a sudden, that could pull your drivetrain around pretty hard too.
Most likely the derailuer was allowed to come too close to the spokes. And when your friend went over a bump or something, things flexed a little, and disaster struck
I would have thought that the plastic spoke protector would have stopped the derailleur moving into the spokes, even if the limit screws was slightly loose. I reckon either the derailleur was a bit bent beforehand, or something like a stick has got caught between it and the spokes.
Could be:
* Object caught in the chain/derailleur (e.g. tree branch, or maybe even a broken spoke)
* Incorrectly adjusted limit screw (would require you to shift to the largest sprocket and beyond)
* Bent derailleur hanger which resulted in the same thing as the above (but you’d notice because shifting would be all wonky)
* Edit: Loose derailleur bolt would also have the same effect as the above (but again, you’d notice because shifting would be wonky)
* Stuck freewheeling mechanism in the rear hub (you’d probably notice problems with the freewheel mechanism before and as far as I’m aware they usually fail in the opposite way i.e. fail to engage)
If you didn’t notice any strange behaviour or noises before and shifting worked flawlessly than the first point is probably what happened.
L screw.