I have 2 bikes, both set up as singlespeeds--a Kona Unit 29'r MTB and a Surly Cross Check. I pretty much rely on my LBS for all my repairs, etc. though I'm gradually learning basic stuff.
My question is, I'm starting to take longer and longer rides, and have an overnighter coming up and hope to do more of that, so I'm guessing it would be good to be able to fix a busted chain by myself if I had to.
From my measurements it appears the MTB (Kona Unit) has a 1/8" chain, while the Cross Check has a 3/32".
My multitool has no chain tool of any kind, but my research suggests I might not even need one - just have some spare links on hand, is that correct? If so....

For the 1/8" I found this: https://www.amazon.com/KMC-Z410NP-Co.../dp/B004JKJLU2

For the 3/32" I'm unclear on what to get. Would it be this?: KMC Missinglink - 10 Speed, Single Link > Components > Drivetrain > Master Links & Pins | Jenson USA

Am I on the right track here? Any advice appreciated!

I carry a KMC missing link for my chain as well. Haven't needed it myself but gave one to another rider a while back. If your chain breaks you most likely need a chain tool. You would need to push out the pins on each side of the damaged link(s) to be able to insert the missing link.

Thanks Jim. I'm totally down with buying a chain tool, I've just been googling all this and getting all kinds of info, some of it conflicting!
So then, I'd be looking at this, correct?: KMC Missinglink > Components > Drivetrain > Master Links & Pins | Jenson USA

That one is for "singlespeed or 9 speed"

I'm a little confused by the chain size thing--as I say, one of my bikes seems to have a 1/8", while the other a 3/32". This Missing Link doesn't say a spec in that regard. Will it work on both?
There ARE different widths available - 7.4mm, 6.6mm, 7.1mm - but I don't understand those specs.

You could simplify things by running 1/8" chain on both bikes.

You will need a chain tool to get the other side of the broken link off the chain.

Each link has two pins. You need to get both pins out to remove the link so that you can use the replacement link. If one pin breaks then you need to get the other pin out to remove the link.

You definitely have to use the right width missing link to match the chain. I've just bought them based on the speed rating. My old Trek 820 is a 7 speed, my road bike is a 10 speed, and my wife's is 11 speed. So far so good. The 1/32 difference between your chains is significant, if the link is just wide enough to fit the chain and lock it should be fine. Any narrower and it wouldn't lock. Any wider and it would probably hang up in shifting and in a derailleur.

Thanks Guys. Think I'll throw the bikes on the car and head to my friendly LBS and have em help me get it sorted out. I see there's different pin lengths available too for these Missing Links, so I want to be sure I'm getting the right thing.

If you have a broken link, you will probably need a chain tool to remove the damaged pieces before you can repair with chain pieces and/or quick-link. Here's one I just bought for ease of packing in a small bag.

For single speed there are two pin lengths. These correspond to the width of the chain. You either have a 3/32" (narrow) or 1/8" (wide) chain.

You just need to know if you have a narrow or wide chain and the LBS should be able to sell you the correct links or you can order it online.

I am 100% certain that if you have a wide 1/8" chain then the KMC brand missing link you need is CL-555.


-Tim-

1/8" chains don't break on the road, as a rule. Derailleur (3/32") chains didn't, either, until we got 8-speed and above chains, because they're made with tighter tolerances. I believe a major factor causing breakage on the road is improper installation.

I don't carry chain tools for two-day trips. The risk just doesn't justify it.

This was almost certainly the case where I gave another rider a missing link. Her bike was just a couple weeks old, 10-speed with Shimano chain, looked like the installation was botched.

My LBS guy doesn't like KMC chains for some reason, but I've never had a problem with them or the missing link. My multi-tool has a light duty chain tool. Given that I already have that with me, carrying the extra link is no biggie.

KMC chains have been champions for me, and I recommend them.

But it's very hard to disengage one of those links without the proper tool to compress it. If I wanted to prepare for chain repairs, those pliers would be in my kit.

I've always been able to do it by hand up to 9 speed chains. Once I got to 10 speed I could not. I made a set of pliers from a pair of mig welding pliers I found in the road by filing/grinding

+1. Over fifty years here of single speed thrashing on BMX, clunkers and cruisers. Never broke a chain. No failure of any kind actually. Not even close. They just go in simple circles, never have to move (get abused) from one cog to another, and are exposed to very low torque forces. I don't even carry a spare master link.

That extra 1/32nd of an inch in chain width will not be a Burden.

are both bikes 1 speed or is the other a [5,6,7,8] speed Derailleur drivetrain?

Both are single speed. Not even chain tensioners in the equation---as SquidPuppet says, just going around in a simple circle!
It's starting to sound like maybe I shouldn't worry so much about this, since a ss chain rarely, if ever, breaks?

I Prefer old style full bushing chains .. pins wider, not flush , side plates wider than the Rollers ,
and the bushing sleeve supports the full width of the roller and the pin , for more wear life.

[MENTION=152773]noglider[/MENTION] and [MENTION=362748]SquidPuppet[/MENTION] make a good point.

Keep them clean and lubed, replace proactively and I've never had a chain fail once since starting to ride in 1977.

The problem improper installation and lack of maintenance. The "Splice old and new chain" thread is a perfect example.

I went ahead and bought a small portable Lezyne chain tool that fits both 1/8 and 3/32 size chains, and the shop gave me a 3/32 Missing Link and a 1/8 master link (the kind with the little clip). Upon examining it all with my bikes when I got home, I see that I have a 1/8" chain on the MTB, and a 3/32" on the cross bike. The links they gave me look like the proper fit (without actually installing them, but they LOOK exactly right to my eyes).
So, now I've got the tool and one of each size spare links, fwiw (after all my hand-wringing over it, if I DIDN'T get this stuff I'd prolly be the guy who's chain would break out there in the boonies for no good reason

I suggest that you ask the LBS for an old worn out chain and practice repairing it at least once at home in a controlled environment.

You don't want to be using the chain tool for the first time out on the road.

[MENTION=418438]TimothyH[/MENTION] gives great advice!

Great idea. I'll stop by the LBS and see if they'll give me an old one to practice on!

My new signature?