Scottcg

I took a brand new chain to a bike shop. They cut the chain too short. I pointed it out. They added a link back by pushing a pin half way out and adding a link. He said it was ok since the pin wasn’t completely out. Is this safe to ride? I thought you couldn’t use a pin once it was pushed out at all
edit: 12 speed sram red flat top chain (ice friction) I know it was too short because I brought my current chain (only 150 miles on it) to measure against. $150 chain so really didn’t want to just buy a new one but looks like that’s what I’m going to do.

veganbikes

I am glad you provided useful info like the number of gears that chain is designed for or how it was determined the chain is too short? Anywho not being a jerk it is generally fine with older chains but the 11-13 speed stuff I probably wouldn't myself however most folks have issues pushing the pin out without going all the way.

JohnDThompson 

It depends on the chain. Pinned chains, like those used on single-speed, fixed gear, and vintage bikes with seven or fewer sprockets on the rear cluster can re-use pins. Modern riveted chains, used on clusters with nine or more sprockets, should use a master link to rejoin the chain ends.

Kontact 

How would the OP know that the number of speeds is relevant? Why would the OP need to tell you why he AND the bike shop agree that the chain is too short? The chain has already been lengthened.

So I disagree with everything you say, including "not being a jerk". Kinda being a jerk, and giving the wrong information about chains.

Here are the facts: SRAM and Shimano 8 speed chains are too narrow to re-use a rivet, as are all chains for speeds greater than 8. There is some confusion about this because Sedis and Campagnolo used to make 8 speed chains that didn't require a special pin or quicklink - but that was because they were designed for Campy/Sachs/Mavic 8 speed cogs that were spaced 5mm like 7 speed. KMC, SRAM, Shimano and all other 'modern' 8 speed chains go with 4.8mm spaced cogs, So if the chain says "5, 6, 7 or 8 speed", that is a narrow 8 speed chain.

If you force an 8 or narrow chain pin in, you damage the flared end of the link that keeps the side plates in contact with it. Force the pin out and back in it can fail under force and pop the rivet free.


There are all sorts of things you might get away with, so whether someone did this without getting hurt is immaterial. This is a known way for chains to fail.

soyabean

If a pin is virgin, it'll still be very taught when it goes back in. I've removed/reinserted a same pin over a dozen times and it's still good. A lot of its reliability comes from not removing the pin completely, so only one end and always that same end of the pin is what gets "worn" while the other side is never touched and remained flared out.

When I fix/resell curb finds that are missing a chain, I re-use everything I have already hoarded, including frankensteining a complete chain if so. A new chain is like $10 and that cuts into beer profits.

Kontact 

And hopefully no one was seriously hurt because of your actions.

79pmooney

@Scottcg, tell us how many cogs you have and what brand. Brand and model of the chain if you know it but that can b4e hard to chase down with just a dirty chain in hand.

With that info, we can tell you whether what the shop did was indeed OK. (What the shop did was common practice 40 years ago and perfectly safe if done with quality riveter and with a modicum of care. That changed as cogs got closer and thinner and chains went to pins that sat flush on the outside.)

cyccommute 

There are ways to add length to the chain but this isn’t it for any chain above 8 speeds…and even that would be somewhat questionable. You could double up on the quick link without issue but any time chain pins are peened (aka “mushroomed”) on the ends to keep the chain from pulling apart under the side load of shifting. Removing the pin breaks that peened bit off and allows the plate to slip off the pin. Often when you remove a pin on a chain, you’ll hear a “snap” which is the peen breaking off. Occasionally, the ring that is broken off will be on the pin of the chain tool.

TLR: No. Just no.

50PlusCycling

You can get a couple Quick Links, this will solve your problem, and allow you to easily remove your chain for cleaning.

veganbikes

Because it is rather important information, why would someone think that useful information is not relevant? I get that maybe you won't but that is on you. Also where did it say the bike shop agreed? The OP felt it was too short and the shop added a link but nowhere did it state anyone was in agreement.

Also where did I give bad advice. I have put in countless pins on 8 and 9 speed chains with zero issues I think you might be thinking about reusing certain master links. Maybe you learned something different from a different mechanic but in my experience and various mechanics I have worked with over the years I haven't heard what you said. I am sure there could be a risk in what you said but I haven't yet seen it.

The not being a jerk was the second part the first part was fully recognizing I was a bit of a jerk and the reason was because I do get tired of people not giving relevant information when they post thinking we are psychic.

Scottcg

Thanks for reply’s. It was a new 12 speed sram red flat top chain I was going to use strictly for races. Seems like the consensus is to just get a new one. My bike mechanic knowledge is minimal so wanted to see what others thought.

Koyote

Perhaps you know how to replace a chain, and merely had the shop do it while the bike was in for some other work -- I've done that. But if you don't know how to do it, you should watch a couple youtube vids, buy a chainbreaker tool, and do it yourself! It's one of the easiest and most-useful skills, right alongside changing your own tires.

Crankycrank

Seems that the "flat top" chain uses a special "flatlock link" so this info could be VERY important. RED Chain | CN-RED-D1 | SRAM You'll need 2 of them to lengthen your chain and says 1 is already included. It looks like the chain has hollow pins that may pose problems trying to re-use, I wouldn't try it.

Kontact 

I guess it is just a problem of empathy. For some reason, you believe that everyone is born knowing that the number of speeds on the cassette dictates the chain type, rather than the derailleurs, gear ratios, shifting system, chain brand, group brand or bike brand. Apparently the OP should have already known what you know.


Since Shimano introduced 8 speed, every mechanic I have ever met has used a Shimano one-use pin to join the chain, or a quicklink when those later became available. The directions to do so are very clear, and the dangers are rather obvious. I was there when these chains came out, and all us groaned about needing to replace a pin every time - but all the mechanics understood why and did it. Re-using quick links isn't the same kind of problem, because quick links don't become week from re-use, they just lose their latch. I wouldn't re-use single-use quicklinks on a jumping or downhill bike, but it never seems to be an issue otherwise because the chain is never not under tension. (One shop I worked at would not reuse them, another did. The first was being smart about avoiding litigation.)

There are people that will use a shift cable in a Vision brake lever, and get away with it. There are people that will put a starnut in a carbon steerer, or cut a carbon steerer with a pipe cutter - and get away with it. The measure of doing the wrong thing is not whether people get away with it, but what happens if it causes a failure. Everyone can do all the stupid stuff they want with bearings, position, shifting, etc. But doing dumb stuff with the structure of the bike is extremely negligent, and the chain is structural because we stand on it.

Please stop telling people that something Shimano declared dangerous 34 years ago is okay. It isn't. If you want to potentially hurt you and yours, at least have the decency to keep it to yourself. 8 speed sideplates are too thin for friction riveting.

Kontact 

Just so it is clear: Your bike shop could have caused you serious injury. They were absolutely wrong about pushing the rivet half out and back in. There is only one way to safely connect this chain.

I would contact the owner or general manager and make it clear to them that what their mechanics did was completely egregious. SRAM's manual says:
That's here in the chain installation section:
https://docs.sram.com/en-US/publicat...se-this-manual

Tell the owner you want all of your money back and a replacement chain. Don't ever go back there.

veganbikes

So nobody should then post any information that is relevant because it isn't empathetic...gotcha! Will keep that in mind.

I have pushed out pins not all the way but partially and re-used on various chains and known plenty of mechanics who have done so. If you are suggesting re-using a fully pushed out pin, I don't subscribe to that and was not what I was talking about and if that was confusing you I am sorry you got confused on that.

Kontact 

No, people should post what they think is relevant, and then other people should patiently ask them for whatever information they didn't know to put in their OP. Instead of insulting them. What a concept, eh? It is called being polite.


Pushing the pin half out damages the peened over edge, so when you push it back in it is no longer being held in that plate the way it was designed. The plate on the other side isn't going to help that.

I feel like you have never seen a broken chain. First the damaged side of the pin goes:


And then the other side can't take the force on its own fails and the chain is severed completely:

grumpus

I'm not sure if it's the pin that gets damaged, so much as the side plate, because you have to ram a larger pin through a smaller hole with brute force both ways, resulting in a loose fit. Also you have to push the pin through further to get it to seat, then push it back a bit. I've done this with my chains if I haven't had a quick link to hand, it hasn't yet caused a problem, but it will probably fail at some point when I'm shifting under load on my e-bike, hopefully off-road rather than in traffic.

Kontact 

You're wrong. It damages the end of the pin.

In the first photo I posted you can see part of the forced out pin, and a bright metal edge on that pin. The bright metal is a lip that was peened down flat against the outside of the sideplate, but is now bent parallel to the pin after being forced through the outer plate. That lip is what makes up for the interference fit that retained pins on pre-8 speed chains.


You re-riveted a link on an ebike? Well that is just extra stupid if it has a BB motor. But the likely failure will happen when standing up on a hill with all your weight on one pedal. The chain then fails and you come crashing down on the top tube.

All this dumbness to avoid using a $3 quick link just boggles my mind.

Iride01 

I was all set to tell you that I'd put back in the pin on a 11 speed chain that I'd made to short. If it hadn't been for the fact I did this on a Saturday after all the bike shops were closed and wanted to ride on Sunday, then I would have just gotten a new chain or gotten a extra quick link. However against all the other nay sayers here on BF when I told them what I'd done, the pin held until the chain wore out and was replaced just prior to reaching 5000 miles.

Since you say you are going to use this chain for racing, then you need to suck it up and get another chain IMO. Or at least get another quick link and use that to add back the other links. Unless this chain does do like some models of Shimano chain and uses a new pin that you break the tapered end off that goes through the hole first. In that case, see if a shop has extra pins.

I don't ride with a hellacious amount of power, nor do I race. So that is one of the reasons I may have gotten away with it.

Trying to get that tiny piece of the old pin lined up to press into the chain properly was a big effort on my part. You don't want that tiny pin to start into the hole crooked.

Welcome to BF!

TiHabanero

Fortunately I have been super frugal since the beginning of time and have developed quite the skill set of scavenging, reusing, and modifying everything under the sun, including 8 and 9 speed chains. Several times I have saved scraps of 8 and 9 speed chains over the course of a summer at the shop and assembled them into usable chains for myself. Have yet to encounter any failures by doing this over the past 40 years.
Honestly, people think too much and limit themselves to what they are told is the limit, when in fact the limit is much further out.

Kontact 

The 'limit' in this case was that old 7 speed chains had straight pins and an interference fit, and 8, 9, 10, 11, 12 speed chains rely on a lip for traction on the outer plate. They are different devices and work differently. Wishful thinking doesn't grow that lip back after you force it off.

veganbikes

I don't wholly disagree with the first statement but when you ask a question it is good to put useful info in the post at the get go.

In terms of your feeling, I really hope you don't become blind or have to touch things for a living, your feeling is way off. I have seen broken chains with some regularity over the years usually not from pushing a pin in a chain. I am sure it has happened many things have happened but I don't know that is a common and at least not in any of the shops I have worked at or with mechanics I have worked with.

frdfandc

Quick links for 10/11/12 speed SRAM drivetrains are designed only for one time use. Remove a QL, install new QL.

frdfandc

As a former LBS manager, this is what needs to be done.