BNB

Shipped my bike, the quick link lost one pin, local shop said they had a quick link in stock and left it for me after hours in mailbox (long drive, shop closed Sunday and Monday). Turns out it is a 12sp sram eagle flat top connector. I'm assuming I cannot use this link with a KMC X12E chain but looking for reality check as my Sunday ride is blown if I can't / shouldn't use this link. Any help with this appreciated.

Just found a new 11sp power lock; would it work?

Duragrouch

I'm not an expert, but I assume by flat top, you mean one of those chain links or connector outer plate that is flat on one side/edge but concave on the other? If so, should work fine, you just install so the concave edge is to the inside (not inboard toward the frame, but inside radius when wrapping around cogs and chainrings); My guess is, that design was done to still have clearance on smallest cog, but the flat top edge provides more strength. Note, some chains these days do have a direction, and which side should be inboard to face the frame. Install, if it rides fine under climbing load (especially on the smallest cog), and shifts fine, you're good I think.

BNB

I'll give it a try. Thanks for the info. Oh, yes, everything you said is correct regarding the flat top link.

Duragrouch

Like I said, I have zero experience with that modern a system, just trying to logic things out. Fit should be most critical on smallest cog, if it works there, probably others as well.

BNB

I'll give it a shot.

FBinNY 

Possible no fit.

Sram flat top chains use a different roller diameter than standard half inch pitch chains.

Since connectors don't include the rollers, a standard connector might be OK, but I don't trust companies willing to pointlessly use non-standard rollers, to not also tinker with pins.

Duragrouch

Thanks as usual, FB. Y'know I wondered about pin size after I posted, but thought, nah, probably same. OP will tell us.

If flat tops use a different roller diameter, that also means only compatibility between their chains, and chainrings, and cogs, and even derailleur pulleys. Well that's lovely. I hope there's a darned good reason for it.

Next thing y'know, they'll have chains with Reuleaux triangles as rotors, I mean rollers.

FBinNY 

It's entirely possible that they stayed with the same pins, which is why I said, "possibly".

As for a, "damn good reason", of course they have one ---- protection of after market business. After all, they can't have THEIR customers buying KMC chains, or brand-X cassettes can they.

Duragrouch

AH, well, if you just mean the roller ID/pin OD as possible change, yeah. But outside roller diameter, yeah, that's a definite compatibility issue. Of course, I don't think they can patent a particular diameter, so stand back, as the aftermarket gears up to produce yet another different standard.

Bikes used to be simple devices with garden-variety parts with inter-compatibility among many part sources. Of course, things like firearms rapidly proliferated to all proprietary parts from the get-go, but at least most of those parts were durable, not needing regular replacing. At least that Buffalo bike I just read about, for Africa or other less-developed nations, is designed for common bike parts, and immensely rugged and durable.

BNB

In the end, I'm going to be cautious and not use it. Not worth the hassle of a broken chain in the middle of nowhere with no cell coverage and certainly no Uber for 300 miles.

I'm not a fan of the variation of bike parts and complications on what should be a simple machine. But when you own N+1 bikes and they're all different, well, I guess it makes life complicated. No bike ride for me today.

Duragrouch

Sorry to hear that. The success of fit should be pretty straighforward; No binding, no more slack lateral* or in tension than other links, doesn't protrude above the other links when wrapped on a cog or chainring, no more visible gap between rollers and teeth than other links.

* I've debated at times what proper side plate gap should be (which can be adjusted with a chain tool); Looser and the chain has more lateral flex and the pins more flush; Closer (but still free pivoting, not binding), may have more bearing area between rollers and inner plate swages, and this may also help keep wax in place if using wax. I should research before I clean and wax a chain as I go back to that.

Camilo

I hope it works out, and let us know. Although it sounds like the shop did you a good favor, I wonder why they didn't understand what kind of link you needed. That's a pretty basic level of (mis)understanding.

I always carry a spare (usually used) link in my saddle bags - for whatever chain is on the bike that the saddle bag is on. Some 9, some 10, some flat top. I've never needed to use one though.

BNB

It does seem the shop should have asked specific question about the exact chain I have.

I too carry spare links but not this time for this bike, apparently. Probably because I had 4 bikes to pack up and ship plus a car and a dog. Way too many things to think about.

Camilo

I was reluctant to post that because, although I "usually" am prepared for stuff to happen, I often lack something I knew I might have needed. No holier than thou intended.

Kontact

I have my doubts that this is going to work. While I can't find X12E on the KMC website, it does say that that the X12 chain is not Flattop compatible, but only Eagle compatible. So I would expect that a Flattop link is going to be too narrow to hook on an Eagle width chain.

A SRAM Eagle or Shimano 12 link would likely work. An 11 speed link might work okay.


Good luck.

Duragrouch

Completely understandable.

Going forward, I cannot overemphasize the helpfulness of checklists, for travel especially. And once done for a given type of trip (or standard template), the big work is done, just go through for each trip. Either print out, or on your phone just put a + in front of the line item after checked off, - if item not satisfied but you want to move on down the checklist and come back to it. On trips, I usually carry a skinny binder with paper backups of checklists, air tickets, maps and directions, etc, in case of phone loss or failure, the binder fits in the front pocket of my carryon roller. I also back things up to my email. Triple redundancy, super easy these days. Revise the date and time at the top of each document so you'll know if it's the most current.

I read an article a couple years ago, the number one factor for reducing errors in surgery, is checklists, and that we should ask our surgical team if they use checklists.

BNB

FWIW, and having nothing to do with the topic, I live by checklists. I have a checklist of my checklists! In the end there are only so many hours in the day, only so much I can do. Checklists can be impossibly long. Mistakes are made despite checklists. I use "Notes" on my phone/computer with convenient bubbles to check stuff off. It's almost fun to see those bubbles get checked off! Today's checklist has 15 items on it - time to get moving!!

grumpus

Rewarding to check things off, depressing to see them still there.

rosefarts

Here’s the stupid part.

An Eagle chain is not a flat-top but it comes with a flat-top link. And it all works great with Eagle.

A 12 speed SRAM road chain is flat-top throughout including the link, and is not compatible with Eagle.

So when you say flat-top, it really depends on whether you’re talking about SRAM 12sp road vs mountain groups.

Camilo

I love my Force AXS bike. But the proprietary flat top chain, and incompatibility with even other Sram drive trains, other 12 speed chains, let alone Shimano or Campag, is really souring me on Sram, and I've been a strictly Sram guy for many years because of the shifting design and ergonomics.

It's just stupid imho.

Duragrouch

" ... a mistake, or DID HE DO IT TO US ON PURPOSE?" - Jack Nicholson, The Witches of Eastwick (1987)

rosefarts

This thread got me thinking about cross compatibility because it could directly impact me.

I carry a 12s quick link on the top cap chain tool on my MTB. It’s not a SRAM and I’ve never used it, so no idea if it would bail me out.

So let’s see some pics.

This is a 12s SRAM road chain from the parts bin. Per SRAM, it is not compatible with Eagle MTB stuff. It comes with a quick link that works.



It’s pretty easy to read.

Next is an Eagle chain, this one is a waxed XX1 but I also have a waxed NX I periodically change between. Note the oil slick quick link. It says Eagle on it. It works great with this chain.




Up next is the rapid link from my top cap chain tool. On close up examination it’s a 12s KMC.




Lets install it on the XX1 chain and see if the walls bleed.




Turns out that it’s a perfect fit. Arguably weaker than a SRAM OEM link but it fits and rotates just as smooth as any other link.


So there we have it. An actual definitive answer.

I’d stay away from the flat-top road stuff but whether it’s KMC or Eagle, you’re not going to have a problem.

Kontact

I don't see a quick link in your Rival photo.

Do you have the ability to try a SRAM road 12 link in a different chain?

rosefarts

I pulled the (no longer used) rival chain from the bottom of a box. I’ll check said box for the link. I have no idea if I still have it. I didn’t look since the question I wanted to answer was with their Eagle line.

I’ll look in the morning. If I have it, I’ll take a pic of it next to the Eagle link, and if they seem close at all, I’ll see if they install on each other.

Gotta get kids fed and in bed now, it’s going to have to wait.

rosefarts

Confirming what we already know.

Oil slick is an Eagle link, silver is a Rival 12s




Rival quick link installed onto an Eagle chain



It was tight but actually installed. It was way too stiff to ride well. I think it would get you home but you’d have a tick, possibly auto shift in each pedal stroke. The road chain has short pins by some fraction of a mm.

Id try it if I had a busted chain and a Good Samaritan had that to offer. As far as packing your repair kit, it’s not going to work well enough to try.