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How did this happen?

Old 08-18-17, 06:17 PM
  #1  
Fritzov
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How did this happen?

Was going to go out on a overnight trip today but after a few hours biking this happened and i had to take a cab back home.

Looking at the pictures what happened and how could this happen?. This happened on a 6 month old Salsa Fargo.
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Old 08-18-17, 06:32 PM
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Limit screws not adjusted properly and the derailleur hooked into the spokes in low gear.... or a stick knocked the derailleur into the spokes. Either way, it looks like you're up for a new rim and derailleur and a hanger most likely.
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Old 08-18-17, 06:52 PM
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What is actually going on there.

The gear cluster in relation to the axle and dork disk, all look wonky.
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Old 08-18-17, 06:54 PM
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Originally Posted by 02Giant View Post
What is actually going on there.

The gear cluster in relation to the axle and dork disk, all look wonky.
I have no idea what is going on, all i know is that it happened when i shifted down to a low gear.
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Old 08-18-17, 07:05 PM
  #5  
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Originally Posted by Fritzov View Post
I have no idea what is going on, all i know is that it happened when i shifted down to a low gear.
That points to a low limit screw not properly adjusted. I expect this is the first time you used the largest cog or at least had to shift to it quickly. The rd moved inward too far and got caught by a spoke.
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Old 08-18-17, 07:17 PM
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The spoke guard will sometimes prevent failures like this, especially if it's a simple overshift due to a limit screw adjustment problem and the guard is large enough in diameter to catch the derailleur (and it looks like it could be). I suggest that the derailleur hanger or the cage got bent by a log or a rock, not enough to cause a failure when it happened, but it was setup for failure the next time it shifted close enough to the wheel. You also didn't say you shifted to "first gear", just to "a low gear". If this was a shift into the third or the second sprocket, that supports the theory that something got bent prior to the shift.
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Old 08-18-17, 08:48 PM
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derailer gets knocked against something and bends the hanger inwards -either in an actual crash, or bumped while parked

rider ignores telltale signs of misalignment: noisy chain, inaccurate shifting

eventually rider shifts into a low gear and the misaligned derailer makes contact with a spoke

wheel and derailer fight to the death, both are mortally wounded and die
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Old 08-18-17, 08:50 PM
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Originally Posted by 02Giant View Post
What is actually going on there.

The gear cluster in relation to the axle and dork disk, all look wonky.
the dork disk is broken loose and hanging off to the side on the right

what looks like an 'axle' that is off center from the cluster (also off the the right and coincidentally near the dork disk), is actually the mounting bolt for the Modular Sliding Dropouts (hard to see because they're painted black).

the actual QR axle can be seen over on the left, centered on the cluster where it should be

Last edited by xenologer; 08-18-17 at 08:55 PM.
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Old 08-18-17, 08:54 PM
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...what has already been said ^^^

Sometimes it happens because the limit screw was not adjusted properly.

But it can also happen if you drop the bike (even just once) on the drive side onto the ground,
and the derailleur hanger gets bent a little bit inboard. So after that it shifts too far inboard.

It's a maintenance item that you need to check regularly. Or just don't shift over into your lowest gear.
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Old 08-18-17, 09:24 PM
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To clarify for those confused by what they are seeing, this bike has Salsa's alternator dropouts. A type of swinging dropout...


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Old 12-16-20, 08:27 AM
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Talk about a deja-vu kind of moment here reading your post. I had the exact same thing happen to me this summer on my 4mo old Salsa Fargo. Pictures could be identical except the color of the bike.

My event happened on a somewhat soft / muddy road when I shifted gears - I was going pretty slow at the time. What I put it down too was possibly being slightly cross-chained when I shifted and there was enough slack in the chain that the derailleur couldn't compensate and everything went south at that moment. The OEM rear derailleur isn't a high end model.

The fix as I'll call it was to replace the bent parts and changed the derailleur to an RX Ultegra - the one with the lever for it. While its an 11 speed model the bike mechanic tuned it up for 10 cog set. It requires a little firmer shifting but its working well. I may over the winter look at doing an upgrade to an 11 speed but I haven't made up my mind as yet.
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Old 12-16-20, 08:33 AM
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look for scrapes on the outside of the derailer. if the derailer took a hit from the outside, it could bend the hanger. it does not take much for the hanger to angle the derailer in enough to catch the spokes when shifted in.

getting a "better" derailer might not help prevent this in the future, as this can happen to any derailer on any bicycle. paying close attention to derailer alignment and limit screw adjustment will help.

in a pinch, you can shorten the chain so it wraps around just one cog on the cassette and use the adjustable dropouts on that bike to make it a single-speed. that's not a long-term solution for most, but if you're far away from the trailhead and don't want to walk a long distance in the wilderness, it could help.
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Old 12-16-20, 08:39 AM
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is the drive side sear stay broke loose from the droup out too?
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Old 12-16-20, 08:44 AM
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Originally Posted by trainman999 View Post
is the drive side sear stay broke loose from the droup out too?
I think that's a split put there on purpose so the bike can be run with a belt drive.
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Old 12-16-20, 10:30 AM
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Originally Posted by mack_turtle View Post
look for scrapes on the outside of the derailer. if the derailer took a hit from the outside, it could bend the hanger. it does not take much for the hanger to angle the derailer in enough to catch the spokes when shifted in.

getting a "better" derailer might not help prevent this in the future, as this can happen to any derailer on any bicycle. paying close attention to derailer alignment and limit screw adjustment will help.

in a pinch, you can shorten the chain so it wraps around just one cog on the cassette and use the adjustable dropouts on that bike to make it a single-speed. that's not a long-term solution for most, but if you're far away from the trailhead and don't want to walk a long distance in the wilderness, it could help.
The bike was pretty new so there were no hits or scrapes to the derailleur. I would post a picture or two but given I'm new to the forum I need a few more posts before I can do that. I only had a 1km walk to get into cell coverage and text for a ride so didn't get creative for a fix. Given it was trashed I figured the upgrade to a better derailleur would be a good move in case it was the derailleur that was the issue and secondly it would position the bike for an upgrade to 11speed later on should I decide to go that way.
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Old 12-16-20, 11:18 AM
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It is 100% not a problem that can be fixed by 'upgrading' the derailleur. GO ahead and upgrade if you like, but this is a common problem that I have seen happen with 15$ derailleurs and 200$ derailleurs - either limit screw adjustment was off, or the derailleur took a knock and the hanger was bent in a bit. NB. the 'knock' to the derailleur doesn't have to be a crash or dropping the bike - it is more common on bikes transported in the back of cars, especially but not only when the rear wheel has been removed.

Most derailleur hangers are intentionally made to be the weak link so an accident doesn't damage the frame or derailleur. Unfortunately, this also means that minor impacts can sometimes re-align the derailleur such that it gets caught in the spokes.
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