Hi,

Just a quick question, I took my chain apart today to give the derailiers and chain a good clean, it didnt have a split link and I just used a tool to push the spin through. Unfortunately I pushed the pin all the the way through and therefore can't put it back together. Question is, should I lose another two links (4 in total) to try and put the chain together or shall I just get a split link? Would losing 4 links be that much of an issue? It seems to me that my chain was tight anyway (just right). Also, what is the best way to add links if you take too many off?

The bike in question is a whyte caledonian c7, hybrid

Might sound like basic questions, I've only been biking for around a year but usually leave it to the shop to maintain my bike, thought I might as well start getting my hands dirty myself

Cheers

It depends, with the chain on the biggest rear sprocket and the largest chainring at the front, if you still have enough slack in the chain that you can join it, you ought to be OK. Chains will always feel tight on a bike with derailleurs as long as you haven't got so much length that the derailleur can't take it all up, so how tight it feels isn't necessary an indicator of length.

Modern chains (say from the mid-80's or so) should never have a pin reused. The chains are narrower than their predecessors and gain their strength from having the ends of the pins flared to rivet them in place. Pushing them partially out removes the flare and leaves a weak spot. Use a specific joining pin for Shimano chains or a master link for any make.

I'll give it a shot, I presume there should still be a little bit of slack even when on the biggest rings. I'll give it a shot and post back tomorrow,

Cheerz

Just seen that last post, I think I'd take your advice on that one, I'm doing a few long rides in the next month or so and don't want to rely on a weak chain. On that basis, as I am now 2 links short, probably 4 when I set the chain up add master links, how would I add another coupe of links, say from another bike chain?

Use a master link. I do not know why you should be 4 links short, but if this is the case you can patch in a few links using two master links. The new links will have to match the width (number of speeds) of the old chain closely. Buying two master links, it might be more straightforward, and not much more costly, to get a new chain which includes its own master link.

I wouldn't recommend adding a few links from a different chain unless you had measured inner/outer width and they were a near perfect match. In addition, you'd end up using 2 master links or new pins to add the extra links and also to join the ends together. The best advice about adding links I think is to avoid taking too many off in the first place. If you're like me and do swap wheels and cassettes and do swap chains, I'd recommend 2 chains. One for the bigger cassette and one for the smaller. It centralizes weak points to the master link which we can replace if it's question. But we don't introduce another possible weakness in the chain by breaking and rejoining chains on a regular basis.

If you have pushed through a pin on one outer link all you have to do is push out the other pin on the same outer link! At that point you have two inner links and can use a quick/master link.

You can rivet the ends with a hammer and a punch.

To get the pin back in, wedge something between the plates of the chain that's solid and about the same width - like a small open end wrench or even a few coins stacked together. Lay it on a hard surface like a concrete floor or the anvil portion of a bench vise. Hold the pin with a needle nose pliers right on the hole and gently tap with a hammer. It will just go in the hole and now you can use the chain tool to push the pin into place. As davidad said, you can then flair the ends with a punch and hammer.

DO NOT attempt to reinstall the pin using the above or any other method. That bike does not have a 1970's old-style chain that would somewhat tolerate such procedures. Attempting reuse, even when the pin has not been removed, can lead to sudden chain failure, damage to your drive train and possible personal endangerment.

Even if I had a chain that would tolerate such actions it makes no sense to do so when the simple addition of a master link removes the problem permanently.

For any newer chain, this is a nearly certain recipe for chain failure, sooner rather than later. Yes, you can get the pin back in this way. Yes, it will also pull out under load at the worst possible time. DON'T DO IT!

Serious question here. What is the explanation for the possible failure? The load on a chain is not lateral so what force would pull the pin out - especially if the ends have been flared even just a tad after installation? I ask this because I have done this after a few "oops" moments and after thousands of miles on a single speed where the load can be significant on a steep, lengthy climb (much, much more than a geared bike), there has never been even the hint of failure.

Again, why? What is it that will cause the side plate to move away from the chain - or the pin to move - and result in a chain failure? Each pair of outside plates has two pins. When one is removed, the plates are still held firm by the other pin. And it would seem reasonable that the more load on the chain, the less likely it would come loose due to the force put on the pins, which is not side to side.

There are a lot of people saying don't do it, but also a lot of people saying they've done it without problem (based on a quick search of the topic).

I would definitely not use a chain that has been taken apart and reassembled this way. Personal experience: I had a chain break when I was accelerating hard through an intersection. It snapped and I lost control - I was sent balance from the sudden loss of resistance, and I ended up going into the curb. Fortunately I just had a slight bonk on the helmet and wasn't hurt at all. In my case, the culprit was probably that corrosion on one of the pins weakened the flared out, riveted part on one side, and eventually the load cycles on it wore down the pin until that side was able to come free.



I imagine that pressing a pin all the way through would risk a similar failure, when using a modern chain. Remember, if the chain is going to fail, it'll probably happen at the worst possible time, when you are accelerating hard, not when you're just riding along. Don't take the risk; it's not worth it to save a few bucks.

That's a fair comment and frankly, an experience I wouldn't want. But my question remains - aside from a general chain failure due to wear or corrosion such as in your case, how would the pin pull out when the load is linear and not lateral? If the pin is corroded to the point where the end simply gave way, I can understand that and that's why we check and replace chains. But I'm trying to figure out why an otherwise good pin would pull out especially if the end was flattened to some degree after reinsertion.

Bottom line is this. I'm hearing that this isn't wise due to possible failure, yet I've personally had no issues. Maybe I'm just lucky and buying my time, but I'm not hearing any reason why this would happen on an otherwise good condition chain with no corrosion or repeated breaking/rejoining of the same pin. Educate me.

Scroll down to "​Procedure for ShimanoŪ Chain".
It is all explained there along with enlarged photos.

https://www.parktool.com/blog/repair-...railleur-bikes

1. The discussion here was in regard to modern derailleur chains, and in the OP's case his bike came with a Shimano chain. Your experience with 1/8" chains is irrelevant, as they are not built the same way. That being said, when Sedisport came out as one of the first bushingless chains we always installed them the traditional way, as repair links were almost unknown at that time. I'm not aware that we ever had a failure, but they required much more care due to the smaller rivet protrusion. I would have never have reinserted a pin on anychain when working on someone else's bike or recommend that anyone else do so. If a person wants to make that decision, fine - but I'm not going to advocate it. Better just to replace a complete link, or the chain if a compatible link is not available.
2. There is plenty of side-to-side stress on a chain every time you shift, as well less than even tension on the side plats in the more angled combinations. Even aside from that it should be obvious that in the normal tension/release cycle of a chain there would be enough vibration and flexing that a side plate that is not tight or confined by a pin flange could easily "walk" its way off the pin. The fact is it does happen, so any theory that it shouldn't is useless.
3. Mechanical issues are not subject to random opinion or anecdotal evidence. The advice to not reuse links on a modern chain is a result of substantial experience and knowledge of chain construction/technology. The fact that some individuals have gotten away with a bad procedure is hardly a reason to risk the result of being one of those for whom it does not work. It is absolutely ill-advised when the solution is both safer and offers more convenience down the road. Rather than ask us why not I would ask you what recommends reuse over just installing a quick-link, other than saving a couple bucks?

I have reused pins on a few older bikes and exactly 136 miles ago on my hybrid mountain/road bike. I put on a new X3 derailleur and broke and reused the pin to join the chain back together. I was cranking up a hill when it went and that made me veer all the way over to the double yellows. I somehow managed to clip out and not fall but if there was a car coming either way, I would have been hit. I am surprised it made it 136 miles before separating and I will never do that again. Luckily I was only 4 miles from the house. I have been more than 10 miles away with that risky setup. Imagine my surprise when I found that a new SRAM chain was a whopping $15.

Just replace the chain. They're cheap. Al

Again, all the OP needs is a quick/repair outer link, or a Shimano repair pin if it's the OEM Shimano chain - end of problem.

i am confused why remving one link will make the chain four links too short

there are three correct ways to handle this situation with a modern chain

remove one pin and chain to do whatever
reinstall chain
use new replacement pin
this one only works with shimano chains

remove one pin and chain to do whatever
remove the other pin from the outer plates that first pin was taken from
reinstall chain
connect with a quicklink made for your size of chain

remove one pin and chain and discard whole chain
install new chain according to chain manufacturers instructions

When the chain is derailed, it experiences some amount of side load. When the gears are in cross-chaining mode and not perfectly centered, there is side load, and over time, that might translate to links popping off the pins and after one end of the link loses integrity, the chain is likely to deform at that link and fail.

But you are right about some of us folks who will push back pins on most any conventional chains 5, 6 or 7speed. And I'll do that on my own chains up to 8speed drive trains. I won't do it with every chain, but it depends on the maker and how much the ends of the pins stick out from the sideplates and how peened the ends are on each link. In a shop situation, I'll usually follow mfg recommendation and replace the pin and charge for it. But between friends and for myself of course, I will take more care to push out the pin and get plates aligned well and push it back in and to make sure any excess pin length is evenly balanced on either side of the plate. Not everyone does this to the same quality and I can understand why the mfg'er of chains recommends a fresh pin or master link to join the chain.

One quick link, and it''s fixed forever, and can be taken apart whenever you need to.

Because that's what forums are for - discussion. I'm not recommending, I just want to know why its not an option. So far I have heard no explanation as to what would cause the failure. I'm willing to listen but "don't do it" and "Shimano says so" aren't really answers. Also, I did it with an old 3/32nd 8spd chain not a 1/8. If the issue is a 9/10spd vs 8spd or fewer, what is the difference between a pin that had the peen sheared off upon removal and a pin that never had a peen in the first place? Keep in mind I'm also considering the flattening of the end of a pin after installation. If we want to get a bike on the road that day and don't have access to a master link the bike can still be made road worthy. And how do those who have chain failure know it was the same link they fixed that broke? Or not an error on the part of installing the pin? Isn't this anecdotal evidence as well? That's why I keep asking for an explanation when I've heard this is such a bad idea. Bash me of you will, but tell me why.

I don't doubt its a slightly weaker point in the chain, I just haven't heard what it is that makes it prone to seemingly inevitable failure.