Derailer torn in half while touring
 

This is to be filed under "lessons learned" and "stuff happens". Pemberton, New Jersey:

I was at the beginning of my fifth day of touring from Delaware to my home in central New Jersey. I was about a mile away from my campsite in the morning when I heard (and felt) a tremendous crunch from my bike. The drivetrain was pretty much frozen.

The chain was hanging in a loose loop, not quite touching the ground, and the derailer was hanging with it. It appeared it had been ripped off the bike. I got off and walked the remaining half-mile to the Dunkin' Donuts I was heading towards.

http://farm5.static.flickr.com/4006/...c81717f907.jpg
Busted derailer by neilfein, on Flickr
It's hard to make out in this picture, but my derailer snapped clean in two.


Ouch. I'd noticed on the way there that the rear wheel was now rubbing the brakes, obviously out of alignment, and probably severely out of true. I imagine a shock like this can't be good for the rear wheel. After some web searching (and a cup of coffee), I found that no nearby bike shops where I could try to get this fixed. I called my wife; she was happy to pick me up, and I settled in for a wait. (If she hadn't been able, I would have asked my friend for help, or rented a car.)

"I've seen this before", said the REI mechanic a week later. "You probably got something caught in your drivetrain, something like a stick or a rock, and it jammed things up." I told him about having ridden through the Cape May peninsula, where the air is filled with salt and the roads have sand blown on them; and also about having camped on a farm the night before, with paths of dirt and straw and pine needles.

http://farm5.static.flickr.com/4015/...faedc77721.jpg
Camp Pine-Needles by neilfein, on Flickr
Packed up and ready to leave the campsite; the bonfire from the previous night is behind the bike. Little did I know I wouldn't get far.

The final bill was just over $100 to replace the derailer and true the rear wheel. (I had them do a full tuneup and cleaning while the bike was there.)

I asked the mechanic how to avoid this in the future, and he told me that the trick is to learn to listen to your drivetrain. If you feel anything sticking or catching, stop and take a look. Pick things out of your drivetrain if needed. Even small objects can hurt. (I'd been squirting some lube on the cogs from time to time, and that can also help. It may have even bought me time until this happened.) Of course, this is an extreme case of what can go wrong!

' glad you're back on the road.

Thanks for sharing.

Spoke protectors , though some disparagingly call them 'Dork Discs' ,
prevent damage from chain going into the spokes ,

a common cause of major rear wheel damage both off road and on tour.

Saves a long walk and pleading phone calls.

I'm fairly sure it worked on mine. The spoke protector was cracked in half, and the chain and derailer stayed on the drivetrain side.

suppose there's a lot to be said for hubs rohloff.

Was a general comment for the rest of the readers,
there is also the wheel lacing priority of having the right side head in spokes not trailing,
so the pedaling force does not pull the chain harder in,
if it goes into the spokes ..
have cut into 14 gage spokes to breaking all of them with one uphill overshift.

Storage dust gathers on my derailleur bikes after getting a Rohloff hub equipped one.
including my nice Touring bike with it.
spoke protected friction shifted 80's Campg MTB derailleur.
6 x 3 drive-train.. It has trip memories though
and some in the field prompted upgrades ..

Is it true it's not good to oil derailleurs because they get dust in them?

I had this happen some years ago. I carry a chain breaker which allowed me to break the chain, remove the derailleur and shorten the chain to make the bike a single speed, allowing me to ride it to a bike shop for repairs. Worth considering as part of your tool kit.

One advantage of horizontal dropouts is that in the event of a damaged derailleur you can setup any gear combination as a singlespeed to get you to the nearest town.
With vertical dropouts you can usually get some gear combinations to work with sufficient chain tension but it may help to experiment at home.

I am glad you were not stranded, and thank you for the interesting picture for demonstrations.

Yes, one thing that can cause a broken derailleur like in the photograph (#1 post), is a mis shift that passes over the biggest rear cog, and wedges the chain between the last cog and the spokes where they cross near the hub.

One must not rely on the cable tension adjustment (shifting) to prevent this, but to check the limiter screw (low-gear, marked L or - sign) and putting thread lock on it or clear nail polish.

The "dork disk" (hilarious name) also do usually work in preventing this. A lot of old schwinn bikes had ornamental metal ones that were chrome plated.
Most bikes now come with plastic ones that are slid onto the hub body behind the cassette. Simply removing this and reinstalling the cassette, can cause the misadjustment of a few mm, CAUSING the wreck described above!

Bicycling Magazine just covered issues about broken spokes in this month's issue. Interesting reading.

Yes there is..any IGH drivetrain actually...especially if that derailleur gets ripped off a long way from a LBS.

Definitely pay attention to weird/unusual noises and feelings. (An obvious suggestion.)

Seems (to me) like an odd thing to do. Seems like a great way to make things dirtier/grittier with little benefit.

By not having an indexed shifting scheme I can feel things thru the lever,
that may be missed in the quick mechanical click.
and like not forcing a shift in an inappropriate part of the terrain.

It stopped the squeaking, and two bike ships have told me, essentially, "it can't hurt!"

I'd love to go to barend shifters, but I haven't had the money. Well, I'm out $100 now. Could barends have helped me feel what was going on in the drivetrain better, possibly avoiding this incident?

What?

I'm going to guess that you are talking about the derailer pulleys. Rather than the cogs (sprockets on the cluster).

It also sounded like you were putting lube on the teeth (of whatever), which would be a useless place for lube.

If your derailer pulleys use bushings, you can disassemble them, clean them up, and put a bit of grease on them (to kill the squeaking). This worked much better for me than "squirting some lube" on the pulleys.

(Some derailers use ball-bearings, which might be a bit more work.)

Neal,
Think about it, a hub flange has spokes coming out each side one goes clockwise , the other goes CCW.

If there is tension on the chain, and the nearest spokes are going CCW the chain will jam in hard,
pulled into the center by the spoke lacing pattern .

wheelbuilding 201, perhaps but a consideration.

Probably not. If you shifted into the spokes, the barend shifters wouldn't have stopped that. Shifting into the spokes can be caused by a bent derailer hanger or an improperly set limit screw. If the bike had been performing well before hand, I doubt that it was a limit screw. Those just don't come out of adjustment once they are set. But it is easy to bend a derailer hanger.

The only advantage of barend shifters over STI is the friction option on the barends. Friction allows you to be sloppy and let your bike get out of tune. STI (and similar systems) require precise cable movement and thus are finicky about adjustment. It's really not much of an issue if you keep the bike tuned.

Friction doesn't really let you 'feel' the drivetrain any better. Your ears will tell you more about the drivetrain than the lever. If you hear something clattering and clunking or something that just doesn't sound right, check it out to see what the issue is.

That happened to me about 25 years ago. The bolt that holds the cage to the upper part of the derailleur came unthreaded. In my case, I heard the metal parts hit the pavement, that was my warning so I had no damage to any other compoonents. I was about 40 miles from home and could not find all of the parts in the grass on the side of the road to reassemble. Major bummer. Fortunately it happened when it did, a half hour later I would not have heard the parts land in the new snow that had started falling.

Sometimes when things go wrong, there is no warning. A few weeks ago on tour my left side bottom bracket cup started unthreading. I was unaware until it had unthreaded out so far that it contacted my crankarm and caused more friction. I did not carry the wrench for it so I had to use a cresent wrench on a pair of long nose pliers to tighten it up. (And retighten it every 5 or 10 miles since I could not get it very tight.) I will never figure out why it started to unthread in the first place, it simply acts as a spacer for the cartridge bearing unit.

I might be the only person out there that has actually purchased spoke protector disks for my touring wheels.