Cykilist2

What can literally happen when your mechanic replaces your close to 3/4 stretch 11spd shimano chain with a same brand 10spd chain, on your 11spd set of Ultegra R8000 components?
SMN CN-HG95 116L 10SP CHAIN SIL-TEC ?


This happened to me in one of my service tune-ups (replacing an old chain).
The results were not pretty. I rode with it for about 3 weeks, including a trek up Waimea Canyon on Kauai.

Before I embellish, I would like to know what *could* happen if the above was done by a "trusted bike shop mechanic"

I appreciate your feedback

Crankycrank

I would think they would be liable for any damage that may have occurred if it's as simple as they installed the wrong chain.

trailangel

Wear Cassette and chain

kyumin2lee

10 speed chains only differ in outer plate thickness, if anything the chain should last longer. The only thing that is degraded is the shifting performance.

trailangel

Ya, that's why the 10sp is 5.88mm wide and the 11sp is 5.5mm wide. Ya, they are the same width.

shelbyfv

Worked well enough for you to ride it for three weeks? Surprising.

Cykilist2

shelby: When you say, surprised, are you surprised that I was able to ride with it in that condition for three weeks problem free? Certainly was not that. Here's what happened.

Frame was damage free up to this point...

2 days into this chain replacement, I dropped it once. pulled it back up around the chain keeper, and scratched up the frame.

Then did 51 miles with 6000' of climbing... After that, the fun began, with drops, almost anytime I went into attack mode. Brought the bike back to the shop, 3 different times, in 10 days, with them addressing OTHER issues, other than the wrong chain size. After I complained about it to a different shop, the guy realized that I was riding with an incorrect chain. This is after I nearly snapped off another derailleur hanger, and split the derailleur pulleys enough so that they fell out of the RD. So, I managed to ride three weeks on it, but you couldn't consider it smooth. I knew something was up, but didn't think I needed to check the work of mechanics that I thought knew what they were doing. In any case, all those pullouts resulted in a badly damaged carbon frame, that I'm none too happy about. AFTER the initial shop replaced the chain, the big chainring, things settled down until a 77 miler (less than a month later, chain at 1/2), where I dropped two times, and couldn't get the chain around the chain keeper (which I assumed was there to keep the chain from dropping inside, and damaging the carbon frame..). In those cases, I shifted without load, and it dropped, then was coming down a hill, stopped, and it dropped, as I started up again. The next day, the shop I bought it from (#3 in this story) took a look at the frame and said, "nope, don't ride. Repair or Replace"

So what I wonder is:
1) Predictably the chain will drop more, if it is ill fitting, like when one puts a 10sp chain on an 11sp drivetrain.
2) Chains will drop when you try and shift under load (I put that one to bed in January)
3) Does a chain keeper (I have a trek, or had) need to be adjusted when a new chain, chainrings, cassette are replaced.
I think I need to be just as well versed as any repair shop is considering I ride as much as I do, or at least check ALL their work before walking out of the shop.

shelbyfv

Yes, I would expect it to be problematic from the start, as it was, apparently. Bummer! The chain catcher should not need to be moved unless the size of the inner ring was changed. It's good to learn basic bike maintenance, do the easy stuff yourself. Better luck with the next bike!

trailangel

I actually don't believe this story.

Canker

Bought a used bike with a 10 speed chain on a 11 speed bike. Weirdly it worked perfectly fine till I bought a second wheelset and new 11 speed cassette. Then it started grabbing in one gear on both wheelset, felt like it was skipping, I actually posted a thread about it trying to figure out what was going on.
https://users.marshall.edu/~kessler8/...516_180352.jpg
Took pics where you can see the cassette grabbing the chain and pulling it down. It took a awhile before I finally notice the tiny little 10s stamped on the chain and I figured out I need to replace it with a 11 speed which fixed the issue.

sch

Locally, a friend and I have about 10k miles between us with 10 spd chains on
ll spd cassettes without any noticeable problems. Mybe we just aren't as
tuned to our bikes operation as much as some seem to be, but no dropped
chains, missed shifts with either mechanical or Di2 shifting. Which is great
as I picked up a dozen NIB KMC 10spd chains for $12 each 8-10 yrs ago,
probably a lifetime supply.

Cykilist2

Cranker: That's the problem I seemed to have. Skipping, Dropping. Too bad I didn't notice the 10s... Someone else did.
sch: maybe, some setups work well interchanging parts like that. Certainly didn't work with the Ultegra 8000 11sp set.
In any case, you would think that something simple like putting on the right speed chain would be elementary, and you wouldn't have to check for that. I did the next time they serviced it, but by then, it's too late.

Racing Dan

Not to excuse the mechanic for installing the wrong chain, but replacing a chain, even if it is the correct one, might result in a skipping chain, if the cassette and/or chain rings are worn. Imo, a good mechanic should identify that as well before handing over the bike, but possibly the only viable option is to replace both chain, cassette and rings.

Racing Dan

It sure does sound dramatic. Not that I ever tried riding with a +1 chain, but the only difference is a few 1/10 mm in width. The difference is so slight that many chain sets are in fact both 10/11 speed. If anything at all, I would expect increased noise from the chain rubbing on the cogs and possibly some false/ghost shifting from the (too wide) chain catching on the shift ramps. All the other issues sound more like issues with the adjustments rather than the chain.

CliffordK

I don't think I have any 10s chains.

However, when I first made the jump to 9s, I had a slightly used chain + quick link that I tried. The quick link disintegrated within a couple of days. So, I decided to try a 6/7/8 chain on the bike. Friction shifted.

I rode it for a few miles, but I just couldn't get the trimming right to keep the thing from chattering. So, within a couple of days riding, that chain was removed, and I sourced the proper chain. I think maybe a couple of gears were ok, probably the smallest sprockets.

As far as 11s, most of my cranks and chainrings I'm using aren't 11s. But, I use a chain to match the rear cassette.

The 10s chain should work fine on the 11s chainrings, with perhaps an issue of cross-chaining small/small.

If the OP is regularly dropping a chain up front, my guess is that it has to do with either excessive chainring wear, or poor derailleur adjustment.

Do you manually trim the front derailleur if you hear rubbing?

Issues on the rear? It is hard to say. That is where one would more likely notice chattering from a wide chain. I suppose ignoring chatter, one could potentially cause excessive cassette wear. Or, perhaps if the chainrings were toast before the new chain, the cassette was too.

I'm not sure about other issues with the rear derailleur. I suppose if things are way out of adjustment, then one could potentially get ghost shifts pulling things sideways.

I have to agree with others... that to some extent this falls on the rider. One should be able to ride the bike around the block and notice that something is way off. Then ride right back to the shop to get it fixed.

I would encourage the OP to carry at least a minimal set of tools, and to know how to use them. If something is stuck, then don't force it, but rather fix it, whether this means removing chainrings or guides.

CliffordK

Oh, another thought.

I'm still trying to figure out how the frame was damaged. Are you getting "Chain Suck"?

Workbench: How to un-suck your chainsuck - Mtbr.com

Not as much of a dropped chain as a poorly disengaged chain?

Iride01 

I just went and measured the chain on my 11 speed Shimano 105. The chain is shimano slx CN-HG601. I was getting about 5.57 mm measuring externally from one side plate to the other going over the pin area.

Similarly I was getting about 5.85 mm on a Tiagra 10 speed equipped bike. All I know for certain is that is a Shimano HGX and I assume Trek put a 10 speed chain on their 10 speed bikes when it left the factory.

So that is a difference of .28 mm or .011 inch. Less than 3/64ths of an inch. To express it in fractions with less than a 10% error you have to go all the way down to 5/512.

Just FYI mostly.

Cykilist2

If the OP is regularly dropping a chain up front, my guess is that it has to do with either excessive chainring wear, or poor derailleur adjustment.

Do you manually trim the front derailleur if you hear rubbing?

Issues on the rear? It is hard to say. That is where one would more likely notice chattering from a wide chain. I suppose ignoring chatter, one could potentially cause excessive cassette wear. Or, perhaps if the chainrings were toast before the new chain, the cassette was too.

I'm not sure about other issues with the rear derailleur. I suppose if things are way out of adjustment, then one could potentially get ghost shifts pulling things sideways.

I have to agree with others... that to some extent this falls on the rider. One should be able to ride the bike around the block and notice that something is way off. Then ride right back to the shop to get it fixed.

I would encourage the OP to carry at least a minimal set of tools, and to know how to use them. If something is stuck, then don't force it, but rather fix it, whether this means removing chainrings or guides.

Cykilist2

OP: I do carry a minimal set of tools with me. Probably not everything to fix every possible situation After the problems surfaced again, I did ride back to the shop 3 different times, in 7 days, to have it addressed. Unfortunately, these issues would start popping up after I was 25 miles into a 60 mile ride.
I don't know what "manually trim the FD" means. Time to check the internet on that one. I had the small chainring replaced, then the big one, after about 3 weeks. Pretty much, during the time I was having this problem (after the 10sp chain went on), the bike had a complete overhaul, I think , in part, to address /fix the problem that eventually got fixed when an 11sp chain, big chainring were put on. Everything settled down after that.

Cykilist2

Clifford: Chainsuck? I'm not sure. Seems like I might be. All I know that when jumping into attack mode, the chain would drop. The damage to the frame was the result of all those "pulls" I had to do get it out of there. Maybe, there was "whipping" too from chainsuck. I don't know.

Bike Gremlin

Using a chain for more speeds on a lower sprocket count cassette is no problem.
Using a chain for fewer speeds could affect REAR shifting - since the chain's outer width is greater than recommended for the sprocket spacing. It might not engage sprockets well.

Inner width is the same for 6 to 11 speed chains. Outer width difference between 10 and 11 speed chains is negligibly small compared to the front chainring spacing (and fd cage width). So it should not affect the front shifting, if the chain drops from the front chainrings, it's probably FD setup error (limit screws, cable tension, FD positioning etc). I'd also check the chain length - whether it's optimal.