If the bike shifts off the inboard side of the cassette, and you don’t have the ‘dork disc’ installed to prevent it from jamming between the cassette and the spokes, then your wheel will bind and put lots of energy into your chain, derailleur, hanger, frame with the results you see here. Happens fast, not really recoverable.
Why did the bike shift off the inside of the cassette? Limit screws out of adjustment or perhaps the hanger got damaged and misaligned just enough.
hike2climb on
Something was wrong probably long before this catastrophe.
No a correctly adjusted derailleur, tightly mounted to a tightly mounted and true hangar will never do this.
From the picture I would guess low limit wasn’t set and the derailleur went into the spokes. Or the hangar got bent inboard at some point and then the derailleur went into the spokes.
Something was wrong before normal riding and shifting and caused everything to explode. Replace hangar and derailleur is the fix. And tune the derailleur this time.
Lemki_ on
The little screws on the derailleur, those are limit screws for the full range. Usually on bikes that don’t have the hanger bent, this only happens when someone has messed with them.
In your case the derailleur hanger is bent, which is causing the chain to pull over even further in the lowest gear causing this situation.
That’s why a straight derailleur hanger is so important.
ViolinistBulky on
Yes. Either the low limit stop wasn’t adjusted well enough or the derailleur/hanger was a bit bent in. The result is the derailleur shifted the chain too far, it overshot the biggest sprocket and got jammed down the back of it against the spokes. It then got dragged around as the wheel kept turning, and the derailleur itself got dragged around and destroyed.
Derailleur is dead, chain could be twisted and dead, dropout hanger is dead, spokes could be damaged gouged by the chain, and worst case the wheel might need replacing/re building.
4 Comments
If the bike shifts off the inboard side of the cassette, and you don’t have the ‘dork disc’ installed to prevent it from jamming between the cassette and the spokes, then your wheel will bind and put lots of energy into your chain, derailleur, hanger, frame with the results you see here. Happens fast, not really recoverable.
Why did the bike shift off the inside of the cassette? Limit screws out of adjustment or perhaps the hanger got damaged and misaligned just enough.
Something was wrong probably long before this catastrophe.
No a correctly adjusted derailleur, tightly mounted to a tightly mounted and true hangar will never do this.
From the picture I would guess low limit wasn’t set and the derailleur went into the spokes. Or the hangar got bent inboard at some point and then the derailleur went into the spokes.
Something was wrong before normal riding and shifting and caused everything to explode. Replace hangar and derailleur is the fix. And tune the derailleur this time.
The little screws on the derailleur, those are limit screws for the full range. Usually on bikes that don’t have the hanger bent, this only happens when someone has messed with them.
In your case the derailleur hanger is bent, which is causing the chain to pull over even further in the lowest gear causing this situation.
That’s why a straight derailleur hanger is so important.
Yes. Either the low limit stop wasn’t adjusted well enough or the derailleur/hanger was a bit bent in. The result is the derailleur shifted the chain too far, it overshot the biggest sprocket and got jammed down the back of it against the spokes. It then got dragged around as the wheel kept turning, and the derailleur itself got dragged around and destroyed.
Derailleur is dead, chain could be twisted and dead, dropout hanger is dead, spokes could be damaged gouged by the chain, and worst case the wheel might need replacing/re building.