Sprout97 

I'm curious, as we --rather I (the captain is responsible for everything that happens [at least in my book])-- managed to both bend the hanger & crack the XTR RD on what ended up being our final ride of last year (non-crash, btw). Our LBS wasn't surprised given frame length & torque. Ric at House of Tandems indicated that it happens more often than one would think. Yet, I've never run into anyone (metaphorically speaking) who's had that happen on either a tandem or a half-bike. Inquiring minds want to know.

radsmd

How did the hanger bend and derailleur crack? There must have been some sort of impact to do that. Highly unusual for that to happen in normal riding without some sort of direct force, such as leaning it against something when stopped, pushed up against the wall or seat if packed in a suv or minivan, etc...

I always carry an extra derailleur hanger just in case something like this happens. Not much you can do about the derailleur though.

andr0id

This makes no sense mechanically.

All the force is transferred by the top segment of chain between the chain ring and the cog. By the time the chain wraps down through the RD, it is slack.

twocicle

It was that sneaky bast*rd named "Not Me"!

The only tandem hanger we ever had bent, was apparently upon new delivery of our Santana to the dealer the bike box fell over. Result was a cracked hanger for which we had to fight to get a replacement once I had figured out why the rear shifting sucked. Since then, we always had a spare but never the need to use it. When traveling, I always remove the RD from the hanger to avoid that potential extra leverage issue.

Trsnrtr

Bent one years ago when bike fell over next to a curb and rear derailleur took the hit.

reburns

It happens, usually due to collision or improper transportation or just falling down on the drive side when trying to prop up the bike. But it can also happen if a link freezes, or something is pulled into the chain, or even trying to back pedal when the gears are not aligned.

my daughter bent hers on her half bike recently through a minor collision. Unfortunately the LBS installed the new one with short screws and it fell off again twice before she figured it out.

Tandem Tom

This October my wife and I were riding the GAP. About 2 miles from Ohioplye we must have hit a stick or something. BANG the RD literal exploded into a dozen pieces, the chain got wedged between the cassette and the spokes. Was able to remove the cassette and make the drivetrain into a single speed to get us back. A nice fellow took us to the bike shop in Confluence ,PA where, knowing the owner, I had use of the shop. New RD, new chain, retued the wheel, and re-aligned the DR hanger and we were off again. Forgot to mention we were touring so we han rear panniers on. A few days later on our return ride the spokes, 3 of them, started breaking! But thanks to disc brakes we made it back to our truck. since then I have rebuilt the rear wheel.

DubT

We bent the hanger when the RD got pushed into the rear spokes. LBS straightened it with no problem.

Sprout97 

I'd really miss-entered when I started the thread. The RD did crack around the upper idler gear. The hanger was maybe only slightly bent, but what was really bent want the drop out for the RD. If I can coax my camera into, I'll post the pics.