Afternoon all,

I have to add a couple of links to a 12-speed 1x Sram drivetrain. My kid wants a 36 tooth chainring instead of a 32.

I have a new chain but the current one has no discernible stretch, so I was going to lop off a couple of links and add them.

I have never had much success with this in the past; the chain pin always seems to end up really stiff and the ‘new’ link won’t flex nicely.

I have a decent chain tool.

any tips from you guys for a better result?

thanks in advance.

Are you opposed to Sram quick links?

The chain goes on half the chainring, so the difference between 32 and 36 is 2 teeth, which is one link pair. Are you sure the chain needs one more link pair?

If it does the only way to add it is with a quick link. Period.

As mentioned above, you must use quick links. Trying to drive a pin back through a 12 speed chain will crack the side plate.

When I shorten my 11-speed chain, the pin's expanded "mushroom/rivet head" end shears off. It can't be reused.
Maybe the current chain is okay. Try the new chainring and "carefully" shift to the biggest cog with the bike on a stand or held by the saddle. Is there any angle left at the pulleys? Does it shift easily to the big cog?

If you actually do need a longer chain, use the new one. Save the shorter one for another project. And yes, quick links are the way to lengthen a chain going back to at least 9 speed.

First…you do NOT have to use any quick links…at all…if you don’t want to. And personally, I wouldn’t use more than one quick link in any chain. I mean it’s possible to include as many quick links as you want. You could make an entire chain of quick links. But they’re not as strong as a regular link so I would only use one. Secondly, the remedy for the stiff link is this…
Once you’ve located the stiff link, place it in the ‘cradle’ of the chain tool farther out from the tool’s push pin ON THE OPPOSITE SIDE that the chain pin was pushed out from. Turn the handle until the tool’s pin contacts the chain pin, and then give it another slight turn…like just ⅛th of a turn or less. That should loosen it. — Dan

It's a 12 speed chain, it needs a quick link. The side plates are thin, the pin is peined over, it will distort the plate when pushed out and again when pushed in - it's no longer "as strong as a regular link". The chain will likely hold together on the work stand, and the test ride, but after that it only needs a heavy shift on the wrong bit of chain ... it's another form of Russian roulette.

This is terrible and dangerous advice for modern chains.

Save the old and good chain for future use with something that it'll work with.

You have checked to be sure the new 36 tooth sprocket on the rear will be inside the specs for the RD haven't you. While it might work if you are outside spec. It also might not work.

How so? Using multiple QLs isn’t recommended. And regarding loosing a tight link…what’s “dangerous” about using the recommended method to loosened and pin/link, and what’s your method?

Dan

As already explained, the tight link isn't the problem. The problem is that the link side plates are too thin for pressed in pins. The pins MUST be factory peened on the ends to not come out of the side plates. Period.

Since the quick links don't interact with each other, there is no limit on how many you can use.

Re-pinning chains hasn't been okay since Shimano went to 8 speeds.

If you contact SRAM they will tell you their quick links are as strong as the chain links. Generally as said above breaking the peened edge reduces the strength needed when shifting between gears, as opposed to a single speed where it can work and unless you have new pins for multispeed like Campagnolo and their peening tool you will chance breakage.

It’s pretty basic knowledge that modern chains with peened pins can’t be safely joined this way.

The solution is simple - if you’re not comfortable using multiple quick links, install a new chain.

I'm sure all that never re-rivet a modern chain is just propaganda BS from Big Quicklink to sell more quicklinks ! !

Don't Be Fooled ! ! Rivet anything that you want and it will be just fine. For a while ..... Probably .... Maybe ....

youtube

Get a new chain or add links using an extra quick link. This is common knowledge since 10 speed. This lesson was learned the hard way, not through hearsay.

It's good until you hit your first hill and then it'll snap.

I feel like I've done this with 8sp and 9sp and was fine? 🤔

With 10 speed chains, you could technically "re-pin" with their special pin.

There was an implied "/s" on that post...

I stand corrected. And I will admit that although I do all my own work on all my bikes…they’re all older, with wider chains. I knew that more modern bikes, with more gears, have the narrower chains, but I wasn’t aware that the pins/rivets on them are peened. Now I understand the necessity for QLs. Sorry for the confusion.

Dan

Those are also rivet chains. The only exception was 8 speed Campy and Sachs that used 7 speed chains. But Shimano has been insisting on a special replacement pin since 1989 Dura Ace 7402.

Quick links are just a nicer replacement for special pins.

"Possibly", you don't need to lengthen you chain.

Shift to the largest cog and see how much "slack" you.
You'll use 1" of what you have.
IF you have say 1-3/4" of slack with my method, I'd use the chain as is. (as an absolute minimum, I'd want 1/2" extra)

quick links: is it a one-time use or can they be re-used after cleaning the chain?

they come in both flavors - the packaging or space should state whether they’re reusable of single-use