teacher

This is what happened on my ride today. No warning, nothing, it just popped right off, jammed up my wheel and stopped me cold. The bike is 3 weeks old. I guess it's time for my bike's first tune up.

playera

That's REAL bad. If this is a new bike, you should get a complete replacement, with free water bottles and Powerbars for the hassle.

playera

And, for the embarassment among all of your Bike Forum friends.

maddyfish

Any frame damage?

And what type of bike?

teacher

No frame damage.
The bike was an 06 lemond poprad.

EDIT: yes, some scratches on the rear stay.

Markok765

Get it "fixed"

Bikedued

Jeez! I've only ever seen that happen on older badly maintained bikes. Never seen it happen on a new bike. I would definitely get some kind of compensation, that is ridiculous.,,,BD

OneTinSloth

i'm not saying this is what happened to you, but i've seen that happen when a shimano chain pin (mostly the 10 speed ones, but also 9 speed pins) fails and was improperly installed. shimano wants the pin on the "trailing" portion of the outer link (if you're looking at the drive side of the bike, this should be the hole that is closest to the rear of the bike when looking at the chain when it is above the chainstay), so that if it does fail, and the link spreads open, it doesn't hook the RD and do what happened to the OP.

did you experience poor shifting prior to this, or hear any loud pops, or have any grinding in your drivetrain? did you shift to a larger cog while standing on the pedals and grinding up the hill? is the chain broken? if so, does it look like one of the outer plates separated from the pin? does that pin look different from all the rest? did the outer plate hook the RD pulley cage? if you answer yes to all those questions, the pin was most likely improperly installed. if not, i don't know what to tell you.

teacher

did you experience poor shifting prior to this, or hear any loud pops, or have any grinding in your drivetrain?
no, only when the derailleur got caught in the wheel

did you shift to a larger cog while standing on the pedals and grinding up the hill?
i was shifting to an easier gear, while going up a slight incline..maybe standing, don't remember but not cranking hard at all.

is the chain broken?
no

no if so, does it look like one of the outer plates separated from the pin?
not sure
EDIT: yes

does that pin look different from all the rest? did the outer plate hook the RD pulley cage?
again, i'm not sure
EDIT: yes

if you answer yes to all those questions, the pin was most likely improperly installed. if not, i don't know what to tell you.
I haven't been riding it hard at all...only about 275 kms on the road. My guess is that it was just a weakness in the metal where the screw went in...does that sound plausible? But thanks for the ideas!

teacher

NO WAY! I love gears even if they break.
Fixies are lame

thedips

WOW that is insane what happened...looks like your derailleur exploded!

HillRider

My first thought was that the chain broke but if it is intact it was either a defective derailleur pivot pin or something hard ( a piece of wire perhaps) got picked up by the chain and run through the derailleur.

I distroyed a nearly new Ultegra rd a few years ago when I rode over a short piece of coat hanger wire and it got flipped up into the chain. The chain survived but the rd was a twisted wreck.

swifty

All I can think of, since your chain is not broken, is an improperly adjusted low-gear set screw. If the set screw was adjusted so that the derraileur would touch the spokes when in the lowest gear, this is what would happen in the worst case.

I would certainly hold whomever installed and/or adjusted that RD responsible IF your chain is OK.

blamp28

You can see a popped chain link in the second picture. My guess is that the chain failed and got caught in the derailleur as it entered the lower wheel. This forced the derailleur to wind up and twist into the spokes and break. Let us know how Trek backs you up on this. They have been great to deal with on my MTB but I have not heard anything on the Lemond line.

teacher

"My guess is that the chain failed and got caught in the derailleur as it entered the lower wheel. This forced the derailleur to wind up and twist into the spokes and break."

Yes, I have taken the bike to my dealer and this is what we suspect as well.

Let us know how Trek backs you up on this. They have been great to deal with on my MTB but I have not heard anything on the Lemond line.

Unfortunately my dealer says that Shimano will likely not cover this under the warranty..but we are looking into it.
Would Trek be able to do anything in this situation since they didn't make the part?

Luis Ocana 1973

Agreed. I think having a fixed gear defeats the purpose of a road bike.

cyccommute 

When you were shifting to an easier gear, were you in a small cog in the back and dropped the chain off the front? If the bike has a triple, were you dropping from the middle gear to the inner ring? It looks to me like the chain caught on itself when you shifted. This is common with triples that have chains that are too long. Yours is a bit more extreme but you can still twist off the derailer that way.

Edit: And, since there is so much twisting going on during this, your derailer hanger is probably severely bent. The bad news...and I really hate to be the bearer...is that your hanger doesn't look like it's replaceable. If it's steel (looks like) the twisted hanger is a problem. If it's aluminum, the twisted hanger is a very big problem.

well biked

The bike is an '06 model but you've only had it three weeks? Was it a bike the dealer just hadn't sold despite having it for over a year, but sold it to you as a new bike, with a full warranty? If so, I don't know exactly how such a thing is handled in terms of the warranty (I would guess the dealer simply deals with the bike's manufacturer, in this case Lemond/Trek), but whatever the case, you should be entitled to having it made completely right. If there's frame damage, a new frame, new derailleur, etc. Whatever it takes. Don't take "no" for an answer. Something wasn't right with the bike, and it wasn't your fault.

teacher

Yes, that's right.

teacher

My bike is only a double.

Blamp 28 called it when he said "You can see a popped chain link in the second picture. My guess is that the chain failed and got caught in the derailleur as it entered the lower wheel

....so my current quandry is whether the chain was properly installed in the first place. "

Deanster04

The dealer where you bought the bike should repair any damage and get you a new RD from Shimano. Shimano should take care of everything the dealer does to the bike. The casting for the RD arm was definitely defective. Good luck.

cyccommute 

I doubt that the chain came apart and got caught in the derailer. There's a lot of room between the plates of the derailer arm and the chain. To catch on the arm, the chain would have to be a long way out of place and would likely separate before causing this kind of damage. A chain with a damaged link is very weak. The pin would slip out of place and the chain would separate...especially if you were to put enough torque on the derailer to tear it apart.

If, on the other hand, the chain had caught on itself...like you'd see in a little ring/little cog combination with a chain that is too long...it would still have enough strength to tear the derailer apart. The derailer is folded back on itself in this combination. When the chain catches on itself, the jockey arm could swing backwards and around the rear cluster. Since you don't have a replaceable hanger, the hanger is strong enough to hold on and the next weakest link in the drivetrain breaks. In this case it's the derailer arm. It's more common to have this happen (still rare, however) with a triple but I could see it happening with a double and a short cage derailer.

I would argue that your chain shouldn't have been left that long when the bike was set up but if you were riding in the little/little combination, you are partly culpable. If you weren't in that combination, dropping the chain from the big ring to the little one can cause the derailer to bounce around a lot...especially if the chain is too long. The end result would be the same.

OneTinSloth

i think you are mistaken. i work in a shop and have seen this particular failure many times, and once actually in person as it happened. it usually happens on brand new bikes (happened on A LOT of '06s when 10 speed ultegra and 105 was first introduced) with chains that were installed at the factory. it goes like this, the pin fails, as you're putting pulling force on it, the link deforms, the outer plate is now sticking out just enough to grab the RD by the pulley cage. it doesn't matter how much force you put into it, because the chain is now stuck on the RD, pulling it backward as you continue pedaling, unaware of what is going on. once the derailleur gets pulled around the B axle as far as it can go, it is going to bend and either go into the wheel, or snap off at the mount. the reason why the pin fails is because it either a) wasn't installed properly in the first place, meaning, it wasn't pushed all the way through one of the plates, or b) a heavy side load was put on it, either from shifting from the smallest cog up to the largest cog all at once, while pedaling very slowly, or shifting in the front while pedaling very slowly.

Bob Dopolina 

+1. Spot on. Seen it. done it.

blamp28

Trek or the dealer should back you up on this unless you have been experimenting with the drive-train on your own in the three weeks you have owned the bike(of course not). Trek/Lemond's Warranty:

Limited Warranty

LeMond Racing Cycles

All LeMond bikes are sold exclusively through our network of Authorized Dealers who we entrust with professional assembly and service of your bicycle. LeMond Bicycles warrants each new LeMond frame, rigid fork, or original component part of the bicycle against defects in workmanship and materials:
For the lifetime of the original owner:

• The bicycle frame, except the fork

For five years:

• Rigid forks
• All Bontrager components and accessories, except consumables such as tires and inner tubes.

For one year:

• Paint and decals
• All original parts, excluding Shimano parts.
• All Shimano parts shall be covered by the stated warranty of the original manufacturer.

This warranty does not cover:

• Normal wear and tear
• Improper assembly
• Improper follow-up maintenance
• Installation of parts or accessories not originally intended for, or compatible with, the bicycle as sold
• Damage or failure due to accident, misuse, abuse, or neglect
• Labor charges for part replacement or changeover

They do not cover improper assembly but the dealer should be accountable if that is the root cause. But note that they do cover components originally installed on the bike such as Shimano etc.

I'm still going with the chain failure. I lost a couple of Shimano chains this way and have been using SRAM for the last five seasons both on and off road.