Accordion

Saw it in a post on the SoCal forum with pics. Ugly. Made me think twice about the mechanical shape of my bike since I go way out into the boonies sometimes.

Minion1

Diegomayra

+1.

Come on, plastic teeth.

tero

I've had a similar experience, even though the limit screws were set properly and the hanger was not bent.

I had previously replaced the cassette and chain, and had set the limit screws. I had also replaced the hanger a few weeks earlier.

I was climbing a long steep hill, and had to zig-zag to keep from stalling. On one of the sharp twists I made, the (aluminum) frame bent just enough to drop the chain between the largest sprocket and the chains. The wheel locked up, and I did a slow motion fall to the side - I was only doing a few mph at the time, so the only damage was to my elbow (and ego).

Nothing on the bike was damaged, though, and I was still able to complete the rest of ride. I've put in a few hundred miles since, and it hasn't happened again. The hanger is still straight, and the limit screws where they are supposed to be.

hhnngg1

I still have my dork disk on my bike. I can take the cassette on and off readily for cleaning, but I leave it on. No reason to go all roadie on everyone, and gives you more stealth factor when you pull up on a roadie paceline and go for the pass!

justkeepedaling

In other words, your limit screws weren't set correctly

3 circles

LMAO.... -- I'm relatively new to cycling & that was the first thing I took off...not because of the "dork" factor but because It was annoying and made noise. -- ( damn murphys law...hopefully the scenerio listed above won't happen to me now that It's off!...)

...still laughing...

tw010r

Be careful it has happened to me before except the derailleur broke off of its hanger into the spokes, and through the seat stay. Needless to say I check my limit screws a lot now.

emveezee

Happened to me on my old 1990's steel bianchi 6 months ago. Had nothing to do with the limit screws though. I was in the middle of the cassette and unwisely continued to pedal pretty hard over a real rough patch of road. Either something hopped up from the road to get caught in the chain, or the bouncing around caused the chain to get caught up in the derailleur cage or pulleys, and derailleur gets pulled up and into the spokes, derailleur hanger gets bent (so far that it goes into the cassette), both front and rear derailleurs break clean through at the pivots, break about 6 drive-side spokes. bike wobbles to a stop. That was pretty much that. Managed to bend the hanger roughly back into line and have been rebuilding with ebay parts since.

ticktockpedal

haha!

Treefox

Can also happen if you set up your derailleur after forgetting the 10-speed spacer ring on Shimano, then realize you've forgotten it, and put it back in, thus moving the whole cassette outboard slightly.

But yeah, usually a limit screw error.

Rear dropout collapse can have nearly identical symptoms though - just it's the derallieur that checks out a moment before the chain seizes, rather than vice versa.

bikerjp

Surely you've been here long enough to recall the (non-serious) reference.

Accordion

Well, there are only two steps to removing a dork disk:

1) Remove the baby bolts from your rear dropouts
2) Burn off the dork disk

If you don't have any baby bolts then they probably were stollen.

tero

Sure, I could've tightened them until I wouldn't get a clean shift, but that's not really the point here...

What I was saying is that even when those screws are at perfectly reasonable settings - i.e. properly set for normal conditions - it is still possible to drop the chain if you flex your frame enough.

Braden1550

You can have your cake and eat it in this scenario, but if you don't know how to bake a cake...