What could have caused a rear derailleur to end up in the back wheel suddenly?What exactly happened to my...
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What could have caused a rear derailleur to end up in the back wheel suddenly?
What exactly happened to my rear derailleur?Replacing multiple spokes (9/36): more like replacing spokes or rebuilding a wheel?
This is a similar question to What exactly happened to my rear derailleur? but with some significant differences.
My bike had recently been serviced (about 3 weeks/500 km previously). All that had been done to it since that was a little tightening of new brake cables and oiling the chain the day before a planned big ride. The RD seemed fine when I oiled the chain. Over the first 100ish km of the ride (link includes pictures of the aftermath) I'd used the full range of gears, front and rear. On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up. I barely unclipped in time and got off to find the RD tangled in the spokes and wedged against the seat stay. After two failed attempts to set up and emergency singlespeed conversion (snapped chain) I got the train and a lift home. No spokes broke at the time but several are damaged (two snapped after about another 150 km with a borrowed rear mech).
All parts were present including the B screw and both cage/axle screws (though one was torn out of its thread) and the mounting screw was still firmly in the hanger (which despite being solid steel was quite bent).
I've started putting the bike back together, but what should I be looking out for either as I reassemble it, or before a ride - I've got a tour coming up.
derailleur-rear
asked 10 hours ago
Chris HChris H
25.5k140114
add a comment |
This is a similar question to What exactly happened to my rear derailleur? but with some significant differences.
My bike had recently been serviced (about 3 weeks/500 km previously). All that had been done to it since that was a little tightening of new brake cables and oiling the chain the day before a planned big ride. The RD seemed fine when I oiled the chain. Over the first 100ish km of the ride (link includes pictures of the aftermath) I'd used the full range of gears, front and rear. On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up. I barely unclipped in time and got off to find the RD tangled in the spokes and wedged against the seat stay. After two failed attempts to set up and emergency singlespeed conversion (snapped chain) I got the train and a lift home. No spokes broke at the time but several are damaged (two snapped after about another 150 km with a borrowed rear mech).
All parts were present including the B screw and both cage/axle screws (though one was torn out of its thread) and the mounting screw was still firmly in the hanger (which despite being solid steel was quite bent).
I've started putting the bike back together, but what should I be looking out for either as I reassemble it, or before a ride - I've got a tour coming up.
derailleur-rear
asked 10 hours ago
Chris HChris H
25.5k140114
1
I don't think the pictures of the end result will add much but I can easily edit them in.
– Chris H
10 hours ago
1
There's sometimes a hint beforehand - if you hear a "tink-tink-tink" noise when in the lowest gear then the rear cage is tapping on a spoke. Doesn't need much more after that to fully catch a spoke.
– Criggie♦
7 hours ago
3
@Criggie I've learnt to investigate a spoke tapping noise promptly, as even a luggage strap can cause a sudden stop. So I think I'd have noticed on a quiet road, but I can never be sure
– Chris H
7 hours ago
add a comment |
This is a similar question to What exactly happened to my rear derailleur? but with some significant differences.
My bike had recently been serviced (about 3 weeks/500 km previously). All that had been done to it since that was a little tightening of new brake cables and oiling the chain the day before a planned big ride. The RD seemed fine when I oiled the chain. Over the first 100ish km of the ride (link includes pictures of the aftermath) I'd used the full range of gears, front and rear. On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up. I barely unclipped in time and got off to find the RD tangled in the spokes and wedged against the seat stay. After two failed attempts to set up and emergency singlespeed conversion (snapped chain) I got the train and a lift home. No spokes broke at the time but several are damaged (two snapped after about another 150 km with a borrowed rear mech).
All parts were present including the B screw and both cage/axle screws (though one was torn out of its thread) and the mounting screw was still firmly in the hanger (which despite being solid steel was quite bent).
I've started putting the bike back together, but what should I be looking out for either as I reassemble it, or before a ride - I've got a tour coming up.
derailleur-rear
asked 10 hours ago
Chris HChris H
25.5k140114
This is a similar question to What exactly happened to my rear derailleur? but with some significant differences.
My bike had recently been serviced (about 3 weeks/500 km previously). All that had been done to it since that was a little tightening of new brake cables and oiling the chain the day before a planned big ride. The RD seemed fine when I oiled the chain. Over the first 100ish km of the ride (link includes pictures of the aftermath) I'd used the full range of gears, front and rear. On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up. I barely unclipped in time and got off to find the RD tangled in the spokes and wedged against the seat stay. After two failed attempts to set up and emergency singlespeed conversion (snapped chain) I got the train and a lift home. No spokes broke at the time but several are damaged (two snapped after about another 150 km with a borrowed rear mech).
All parts were present including the B screw and both cage/axle screws (though one was torn out of its thread) and the mounting screw was still firmly in the hanger (which despite being solid steel was quite bent).
I've started putting the bike back together, but what should I be looking out for either as I reassemble it, or before a ride - I've got a tour coming up.
derailleur-rear
derailleur-rear
asked 10 hours ago
Chris HChris H
25.5k140114
asked 10 hours ago
Chris HChris H
25.5k140114
asked 10 hours ago
Chris HChris H
25.5k140114
asked 10 hours ago
Chris HChris H
25.5k140114
asked 10 hours ago
Chris HChris H
25.5k140114
25.5k140114
1
I don't think the pictures of the end result will add much but I can easily edit them in.
– Chris H
10 hours ago
1
There's sometimes a hint beforehand - if you hear a "tink-tink-tink" noise when in the lowest gear then the rear cage is tapping on a spoke. Doesn't need much more after that to fully catch a spoke.
– Criggie♦
7 hours ago
3
@Criggie I've learnt to investigate a spoke tapping noise promptly, as even a luggage strap can cause a sudden stop. So I think I'd have noticed on a quiet road, but I can never be sure
– Chris H
7 hours ago
add a comment |
1
I don't think the pictures of the end result will add much but I can easily edit them in.
– Chris H
10 hours ago
1
There's sometimes a hint beforehand - if you hear a "tink-tink-tink" noise when in the lowest gear then the rear cage is tapping on a spoke. Doesn't need much more after that to fully catch a spoke.
– Criggie♦
7 hours ago
3
@Criggie I've learnt to investigate a spoke tapping noise promptly, as even a luggage strap can cause a sudden stop. So I think I'd have noticed on a quiet road, but I can never be sure
– Chris H
7 hours ago
1
1
I don't think the pictures of the end result will add much but I can easily edit them in.
– Chris H
10 hours ago
I don't think the pictures of the end result will add much but I can easily edit them in.
– Chris H
10 hours ago
1
1
There's sometimes a hint beforehand - if you hear a "tink-tink-tink" noise when in the lowest gear then the rear cage is tapping on a spoke. Doesn't need much more after that to fully catch a spoke.
– Criggie♦
7 hours ago
There's sometimes a hint beforehand - if you hear a "tink-tink-tink" noise when in the lowest gear then the rear cage is tapping on a spoke. Doesn't need much more after that to fully catch a spoke.
– Criggie♦
7 hours ago
3
3
@Criggie I've learnt to investigate a spoke tapping noise promptly, as even a luggage strap can cause a sudden stop. So I think I'd have noticed on a quiet road, but I can never be sure
– Chris H
7 hours ago
@Criggie I've learnt to investigate a spoke tapping noise promptly, as even a luggage strap can cause a sudden stop. So I think I'd have noticed on a quiet road, but I can never be sure
– Chris H
7 hours ago
add a comment |
2 Answers
2
active
oldest
votes
Every time I've seen a rear derailleur go into the spokes while riding it was because something made the chain jam in the rear derailleur and the force of pedaling tore it off and put it into the spokes.
a few possibilities:
- broken chain - if the chain breaks in such a way that it won't go through the pulley cage.
- Foreign object in the chain - something gets caught in the chain in such a way that it won't go through the pulley cage.
- Incorrect chain installation. If a chain was installed such that the pin wasn't seated correctly the chain can pull apart under stress and get stuck in the pulley cage.
- On an abused chain (not like your well oiled chain) links can get tight or rusty and fail to make the sharp bends between the pulleys and get stuck.
Do a careful inspection of your chain when putting your bike back together.
answered 10 hours ago
David DDavid D
2,246214
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
1
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
add a comment |
On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up.
I've had similar things happen not once, not twice, but three times. Uphill, shift to the smallest gear, hear a grinding noise for a few seconds, then BAM the rear wheel locks up with a broken rear derailleur in the spokes.
What I think happened was the chain dropped inside the largest cog, got stuck, and dragged the derailleur into the spokes.
Now, why would an otherwise well-adjusted bike do that in that situation? I've never had problems with the chain dropping inside the largest cog outside of that situation. At all. Ever. Yet I've had it happen three times on two different bikes - and each time when climbing. I think it's related to load and frame/wheel flex when climbing.
Under climbing loads, I think my chainline was changed and/or the derailleur position moved relative to the cogs, making it more likely for the chain to drop inside the largest cog where it got wedged and wreaked havoc on the entire drive train.
I'm also 200+ lbs and have no problems hitting 1200W+ peaks...
So now I ride with a spoke protector/dork disk to prevent the chain from dropping inside the largest cog.
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
add a comment |
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2 Answers
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active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Every time I've seen a rear derailleur go into the spokes while riding it was because something made the chain jam in the rear derailleur and the force of pedaling tore it off and put it into the spokes.
a few possibilities:
- broken chain - if the chain breaks in such a way that it won't go through the pulley cage.
- Foreign object in the chain - something gets caught in the chain in such a way that it won't go through the pulley cage.
- Incorrect chain installation. If a chain was installed such that the pin wasn't seated correctly the chain can pull apart under stress and get stuck in the pulley cage.
- On an abused chain (not like your well oiled chain) links can get tight or rusty and fail to make the sharp bends between the pulleys and get stuck.
Do a careful inspection of your chain when putting your bike back together.
answered 10 hours ago
David DDavid D
2,246214
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
1
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
add a comment |
Every time I've seen a rear derailleur go into the spokes while riding it was because something made the chain jam in the rear derailleur and the force of pedaling tore it off and put it into the spokes.
a few possibilities:
- broken chain - if the chain breaks in such a way that it won't go through the pulley cage.
- Foreign object in the chain - something gets caught in the chain in such a way that it won't go through the pulley cage.
- Incorrect chain installation. If a chain was installed such that the pin wasn't seated correctly the chain can pull apart under stress and get stuck in the pulley cage.
- On an abused chain (not like your well oiled chain) links can get tight or rusty and fail to make the sharp bends between the pulleys and get stuck.
Do a careful inspection of your chain when putting your bike back together.
answered 10 hours ago
David DDavid D
2,246214
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
1
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
add a comment |
Every time I've seen a rear derailleur go into the spokes while riding it was because something made the chain jam in the rear derailleur and the force of pedaling tore it off and put it into the spokes.
a few possibilities:
- broken chain - if the chain breaks in such a way that it won't go through the pulley cage.
- Foreign object in the chain - something gets caught in the chain in such a way that it won't go through the pulley cage.
- Incorrect chain installation. If a chain was installed such that the pin wasn't seated correctly the chain can pull apart under stress and get stuck in the pulley cage.
- On an abused chain (not like your well oiled chain) links can get tight or rusty and fail to make the sharp bends between the pulleys and get stuck.
Do a careful inspection of your chain when putting your bike back together.
answered 10 hours ago
David DDavid D
2,246214
Every time I've seen a rear derailleur go into the spokes while riding it was because something made the chain jam in the rear derailleur and the force of pedaling tore it off and put it into the spokes.
a few possibilities:
- broken chain - if the chain breaks in such a way that it won't go through the pulley cage.
- Foreign object in the chain - something gets caught in the chain in such a way that it won't go through the pulley cage.
- Incorrect chain installation. If a chain was installed such that the pin wasn't seated correctly the chain can pull apart under stress and get stuck in the pulley cage.
- On an abused chain (not like your well oiled chain) links can get tight or rusty and fail to make the sharp bends between the pulleys and get stuck.
Do a careful inspection of your chain when putting your bike back together.
answered 10 hours ago
David DDavid D
2,246214
answered 10 hours ago
David DDavid D
2,246214
answered 10 hours ago
David DDavid D
2,246214
answered 10 hours ago
David DDavid D
2,246214
2,246214
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
1
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
add a comment |
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
1
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
That chain is in the bin, badly damaged and I've got a new one on there. While not the most forceful bit of pedalling of the ride it's possible the chain opened up just then - though it had only recently been fitted by the LBS. Something getting caught is certainly a possibility I can't rule out though I try to avoid debris and don't recall any
– Chris H
10 hours ago
1
1
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
@ChrisH Even badly damaged if the bin hasn't been taken away it would be good to get a look at the link on either end of the chain.
– David D
10 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
I keep a metal bin in my garage for recycling so I've still got at least most of it. I had to drive a pin out to remove it so it wasn't completely broken even after the RD was, though some had a permanent twist (I removed that bit of course, but took it home - any littering was unintentional). There was no pin sticking out when I attempted to convert to single speed, but there was afterward that failed so I can't tell which bit to inspect.
– Chris H
9 hours ago
add a comment |
On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up.
I've had similar things happen not once, not twice, but three times. Uphill, shift to the smallest gear, hear a grinding noise for a few seconds, then BAM the rear wheel locks up with a broken rear derailleur in the spokes.
What I think happened was the chain dropped inside the largest cog, got stuck, and dragged the derailleur into the spokes.
Now, why would an otherwise well-adjusted bike do that in that situation? I've never had problems with the chain dropping inside the largest cog outside of that situation. At all. Ever. Yet I've had it happen three times on two different bikes - and each time when climbing. I think it's related to load and frame/wheel flex when climbing.
Under climbing loads, I think my chainline was changed and/or the derailleur position moved relative to the cogs, making it more likely for the chain to drop inside the largest cog where it got wedged and wreaked havoc on the entire drive train.
I'm also 200+ lbs and have no problems hitting 1200W+ peaks...
So now I ride with a spoke protector/dork disk to prevent the chain from dropping inside the largest cog.
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
add a comment |
On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up.
I've had similar things happen not once, not twice, but three times. Uphill, shift to the smallest gear, hear a grinding noise for a few seconds, then BAM the rear wheel locks up with a broken rear derailleur in the spokes.
What I think happened was the chain dropped inside the largest cog, got stuck, and dragged the derailleur into the spokes.
Now, why would an otherwise well-adjusted bike do that in that situation? I've never had problems with the chain dropping inside the largest cog outside of that situation. At all. Ever. Yet I've had it happen three times on two different bikes - and each time when climbing. I think it's related to load and frame/wheel flex when climbing.
Under climbing loads, I think my chainline was changed and/or the derailleur position moved relative to the cogs, making it more likely for the chain to drop inside the largest cog where it got wedged and wreaked havoc on the entire drive train.
I'm also 200+ lbs and have no problems hitting 1200W+ peaks...
So now I ride with a spoke protector/dork disk to prevent the chain from dropping inside the largest cog.
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
add a comment |
On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up.
I've had similar things happen not once, not twice, but three times. Uphill, shift to the smallest gear, hear a grinding noise for a few seconds, then BAM the rear wheel locks up with a broken rear derailleur in the spokes.
What I think happened was the chain dropped inside the largest cog, got stuck, and dragged the derailleur into the spokes.
Now, why would an otherwise well-adjusted bike do that in that situation? I've never had problems with the chain dropping inside the largest cog outside of that situation. At all. Ever. Yet I've had it happen three times on two different bikes - and each time when climbing. I think it's related to load and frame/wheel flex when climbing.
Under climbing loads, I think my chainline was changed and/or the derailleur position moved relative to the cogs, making it more likely for the chain to drop inside the largest cog where it got wedged and wreaked havoc on the entire drive train.
I'm also 200+ lbs and have no problems hitting 1200W+ peaks...
So now I ride with a spoke protector/dork disk to prevent the chain from dropping inside the largest cog.
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
On a gentle uphill, at least a few seconds after changing down, there was a nasty noise and the back wheel locked up.
I've had similar things happen not once, not twice, but three times. Uphill, shift to the smallest gear, hear a grinding noise for a few seconds, then BAM the rear wheel locks up with a broken rear derailleur in the spokes.
What I think happened was the chain dropped inside the largest cog, got stuck, and dragged the derailleur into the spokes.
Now, why would an otherwise well-adjusted bike do that in that situation? I've never had problems with the chain dropping inside the largest cog outside of that situation. At all. Ever. Yet I've had it happen three times on two different bikes - and each time when climbing. I think it's related to load and frame/wheel flex when climbing.
Under climbing loads, I think my chainline was changed and/or the derailleur position moved relative to the cogs, making it more likely for the chain to drop inside the largest cog where it got wedged and wreaked havoc on the entire drive train.
I'm also 200+ lbs and have no problems hitting 1200W+ peaks...
So now I ride with a spoke protector/dork disk to prevent the chain from dropping inside the largest cog.
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
answered 9 hours ago
Andrew HenleAndrew Henle
3,396915
3,396915
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
add a comment |
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
I had a spoke protector (until that point, I've still got pieces of it), and it's out possible that I changed into the biggest sprocket. Of course behaviour under load is one of the hardest things to test, but I wasn't even breathing very hard, probably putting out no more than about 250W (I'll check strava's estimate) unlike the brief 15%er a few minutes earlier. That's one of the things that surprises me - the timing. I don't trust my lack of reflection of a grinding noise
– Chris H
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
@ChrisH I don't trust my lack of reflection of a grinding noise First, see if there are any deep gouges in the parts of what's left of the spoke protector that was behind the largest cog. If there are, then the chain probably got in there before things snapped. If not, check the chain then. If one of the plates came loose and caught in the RD, that could explain what happened - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link.
– Andrew Henle
9 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
I'll look at the pieces but it's pretty smashed up
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
And of course it was supposed to be "recollection" but my train was about to go into a tunnel before I could check
– Chris H
7 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
@Andrew Henle " - and that's the kind of failure I'd expect from a new chain, especially if it's one that doesn't use a quick link." I'm curious about the reasoning behind this. (Not doubting you, just respectfully trying to learn more). Why would you expect a new chain to do this?
– Jeff
2 hours ago
add a comment |
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1
I don't think the pictures of the end result will add much but I can easily edit them in.
– Chris H
10 hours ago
1
There's sometimes a hint beforehand - if you hear a "tink-tink-tink" noise when in the lowest gear then the rear cage is tapping on a spoke. Doesn't need much more after that to fully catch a spoke.
– Criggie♦
7 hours ago
3
@Criggie I've learnt to investigate a spoke tapping noise promptly, as even a luggage strap can cause a sudden stop. So I think I'd have noticed on a quiet road, but I can never be sure
– Chris H
7 hours ago