Not to sound rude but does it really matter? Perhaps the 11 speed cassette and 11 speed chain weigh less than a 12 speed cassette and a 12 speed chain due to less material.

If you are concerned about chain weight manufacturers often mention the weight in the product description. I have seen titanium cassettes if you have the money, perhaps titanium chains are out there also.

.

---

Once, I was fast. But I got over it.

Looks like they're basically equivalent, slightly lighter for 12 speed. 11 speed: 247g for 114 links, 12 speed: 249g for 116 links. 2.17 g/link vs 2.15g/link. Definitely not a difference that matters.

Appreciate that!

In theory a 12spd chain will be lighter since the pins and rollers are narrower. In practice, chains of the same speed have different weights (dura ace is less than 105, wipperman might be less than sram, etc.), so the question does not have an absolute answer.

There is also the system to consider. A 12spd will have an additional rear cog, and the wider range may result in using an RD with a longer cage. Complex systems, thus the complex answer.

---

ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

Yes.. My thoughts are every little bitty watt you produce is scrubbed by the chain.
If we have the lightest chain (assuming its clean & waxed etc) by the end of an IM those watts add up.

Marginal yes, but better

In that case what you want is the lowest friction chain, not the lightest. For example, dura ace chains are lower friction than sram even when identically lubed (ideally waxed).

Check out Friction Facts on the lowest friction chains and waxes. There are several companies that make “race day” chains that have been specifically prepared to reduce losses.

Side note: every watt “scrubbed” by the chain is also impacted by other systems; for example tires/tubes. There are lots of areas for reduction of frictional losses.

---

ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

The weight of the chain has nothing to do with friction.

Although 12s Dura Ace is not as low friction as 12s, and so you need to now go to KMC for the lower friction.....

However in real life, as 12sp is 9.1% faster than 11sp (12/11) then for the same power (holding same constant NP on headunit) then to obey the laws of physics with the conservation of momentum, and we know that's speed x mass you can see the 12sp chain will become the equivalent of 9% lighter at race pace.

The above para is written in the style of any manufacturer white papers you've seen on bike and wheel aero in the last 5 years.

And one other tiny correction to the above, someone suggested the rollers are narrower. That's incorrect, the rollers are the same width, it's the plates on the side that are thinner, which does mean the pins are fractionally narrower. The outside width is narrower, but the inner width is the same.

Thanks for the correction on the rollers. Yes, it's the pins that are shorter; though the thinner sider plates are lighter as well.

High-level to the OP: it's not the weight difference that matters that much; differences in frictional losses between chains are far more important.

https://zerofrictioncycling.com.au/...e-data-consol-v3.pdf

---

ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

That was true with 11sp, not with 12sp, though.

SRAM and Shimano 12sp chains are about the same friction. Campy and KMC are both a bit faster.

Zero Friction Cycling.
CeramicSpeed.

ZeroFriction has 12sp DA/Ultegra and SRAM AXS Force/Red all at a "2".

CeramicSpeed found the Force AXS chain slightly faster than Shimano 12s after 5 hours @250W. With UFO treatment. Shimano has slightly faster factory grease, so is faster untreated. But who does that?

For Shimano drivetrains, KMC looks like the speed king. Only flattop chains work well with SRAM AXS, though.

Is that flattop only chain on Sram AXS actually true tho? I see it said all over, and then I hear it's only Sram Eagle, and then I see plenty of guys running not flattop chains on Sram.

I understand it's in Srams best interest, both legally and economically, to say the only allowable chain is the flattop.

It's probably true. The roller is a different size. It's a real, measurable difference in a key aspect of the chain, not marketing mumbo-jumbo. I think you can change out jockey wheels and do a little better, as apparently the jockey wheels don't work well at all without flattop. But even then you're probably going to be compromised in performance, and with rollers not meshing as designed with the teeth, probably not getting any gains in efficiency either.

I've never seen anyone use non-flattop on AXS. Granted I don't exactly look.