I got tired of the chain cleaning hassle with a mounted chain so I added a KMC link to one of my Campy 10 speed chains. Most of my bikes already have them. The installation went well and soon I had a clean chain and cassette. Reinstalled the chain and shifted through the gears on the stand with no problems. Later that day went out for a 50 mile ride with friends with no shifting problems, however, the chain sounded loud. After I got home, it dawned on me that I must have installed the chain upside down creating a situation where the worn cassette meshed with a new chain. Bad!!

A quick switch rectified the problem. I'll be more careful next time. Direction of travel and orientation are important.

I don't remove my campy chains except to replace but I've never heard of a directional chain. Still not clear what you are talking about.

I turned the chain upside down using the "new" side of the chain rather than the "worn in" side. Also, if you reverse the direction of travel, the chain will be running backwards creating a new wear pattern.

never heard of that one. i have 7 bikes and all of them have the missing link. i've never paid attention on if they are upside down or not. i've never had a problem.

you should try riding with the chain right-side-up but the bike up-side-down. now THAT creates a new wear pattern.

i did that once, and your right it created a new wear pattern down my back and shoulders.

My head hurts just thinking about that!

New one on me, too. One thing you don't want to do is install the slip link backwards. That will cause problems.

With a chain saw, on the other hand, it is a big deal. Cuts a lot better when the chain is pointed in the right direction.

Yeah, may not be exactly what you are talking about, but a few days ago I just replaced my first modern chain (Shimano 105 Chain). I say modern b/c of getting back on the bike last yr after 13 yr hiatus, I was only used to changing the old Sedis, or Sachs chains that were bi-directional chains. As per the instructions of the new 105 chain, I had to be sure that I installed it in the correct direction (stamped lettering on links righ-side-up when viewing bike from dirve-train side).

There is no upside down on a chain. They have rollers, so the wear moves about the roller. Some chains have direction, at least per their marketing.

If you used a KMC missing link on a Campy chain, you have to use the one specific to Campy 10 speed or 11 speed chain. A KMC link sold for a Shimano chain will make a noise through the cassette.

Yep, used the correct Campy link.

The wear pattern that I noticed showed up on the side links not the rollers. Not sure what is causing this pattern, maybe it is caused from tension between the cassette and the chain ring rubbing the front derailleur??. When I reversed the chain the noise disappeared.. Who knows, I have at least 6 bikes both Shimano and Campy with missing links and have never bothered to check. This is the first time I've had problems. Oh well, an easy fix.

Uhhhhhhh.......wut?

Now I've got to go examine my old worn-out chains with a magnifying glass! My assumptions has always been it would make no difference upside-down because of reasoning similar to above, the wear being internal in the links between the plates. But what if the links are worn more closer to one side and less in the middle? Turning the chain over would reverse that. If it even happens that way. What if each plate was bent infinitesimally in one direction because of a skewed chainline? Again that would be reversed. Is the chain actually worn that way, I don't know but hopefully if so there's some way to detect it.

This applies to roller chain, and should carry through to bike chain:

Link plate wear is uncommon as link plates are usually made out of 1040 or 1045, and through hardened. This means the hardness is full depth, and appreciable wear is very slow. Rollers are also full hard.

Pins and bushings are case hardened 1018 or 1020, with a fairly shallow case (.006-.008" on #40 chain, which is closest to bicycle). This shallow case, with a soft under layer (think nuggat), wears quickly and shows developed wear more quickly. With bike chain having a combined roller/bushing, I would expect it to be case hardened.

I think the title of this thread is very descriptive.

really? upside down?

My campy 10 chain with 6,000 miles on it had less than .15% elongation of about 1/16" over the full length. This figures out to be about .0006 inch of wear for each pin and pair of inner side plates. In contrast, each roller was about .005 inch smaller on the OD and about .010 larger on the ID. The side clearance between the inner and outer plates was a round .013 inch, which is about twice the clearance on a new chain. All of these amounts of wear are much greater than the pin/bushing wear. I also measured the space between the rollers and found that the original .200 inch reading had increased to about .240 inch, which is a huge increase, but it reflects the wear on two rollers - inside and outside.

What I discovered is that there is more to chain wear than just elongation. Despite the chain's low elongation, it was totally shot. It also wore one of the cogs on the cassette enough that it skipped with a new chain.

I had another bike in use at the time that had Ti cogs. After only 4,000 miles and even less chain wear, the 19 and 21T cogs wear both worn enough to cause new-chain skip.

After that, I began using the roller spacing as my most important gage of wear and also started using 3-4 chains in a fairly frequent rotation, so I never get new-chain skip and the cassette will last for the entire life of all the chain in the rotation.

Again, my knowledge is specific to roller chain:

To really measure component wear, you need to apply a static load of 1% of Ultimate, which is 18 lbs measuring load on a #40 or #41 chain (41 is the old ANSI designation for bike chain, but would have probably been an old 5 speed chain at this point). Under measuring load, the amount of wear seen grows dramatically, but again, this may be more pronounced on roller chain, with roller to bushing wear and bushing to pin wear.

Also, modern bike chain may not use a full hard link plate. Your information is very detailed, and a softer link would show more wear between plates.

Another interesting thing, most folks have no idea how much a chain will grow in length under load. We prestressed chain to 40% of ultimate at assembly, and you would have to allow 3/8" growth on 16" of chain (for 1/2" pitch chain, or essential 32 joints). Granted, that is a 700# load, and more than a bike sees in use, but anyone who thinks chain length is static under load is mistaken.

I've also measured brand new chains with my full-length measuring gage and found them only slightly short of an even-inch number. I always credited that to all the grease-like lube. I suspect that one ride would bring the chain to full length, without any significant load.

More than likely, the OP simply put his chain on the wrong side of the chain guide between his jockey wheels. He examine that little piece of metal for marks on the outside.

Actually I think it's the opposite. It's ACTUALLY saying:

1. In reality the OP is smart because unlike the rest of you dummies he knows there is an upside down side to a chain and YOU DIDN'T!
2. Or, the OP is really hard on himself to call himself stupid three times for a trivial mistake that really amounts to no big deal, didn't even prevent him from riding.

I'm feeling nice so let's go with number two. Relax OP, you're not that stupid. Trust me, I've done stupider things um...just about every day of my life...including saying stupider.

Hilarious. good one ahsposo. Gotta love da 41.

Some of Shimano's chains (6700 Ultegra, 7900 Dura Ace?) are "directional" in that they have inner and outer plates.

yup!

New Dura Ace chains are indeed directional. Put them on wrong, they shift like crap, put them on right, shifting's dead on perfect.