Sram Chains are That Slow?

Triathlon Forum
1

https://cyclingtips.com/2019/12/the-best-bicycle-chain-durability-and-efficiency-tested/#efficiency-comparison

They show chains treated the exact same have an increase of friction of 40% over Shimano 11 speed chains.

I would imagine two stock chains would have an even wider margin. Friction Facts original reports of 11 speed chains had Shimano chains 2 watts faster than Srams 11 speed (if I remember right) which would put their 12 speeds even slower. Likely widening out to 3-4 watts.

So in the end best case scenario is 2 watts and worst case 4 watts.

I know we are talking small numbers. But why are they moving in the wrong direction? Not to mention the AXS chain is twice as expensive.

I was looking at going Force AXS but I am no longer. Seems like a lot of $ for additional friction, and extra weight.

2

Yep, Hambini been saying SRAM is shite, guess he was right!

3

So in the end best case scenario is 2 watts and worst case 4 watts.

Not sure what you mean, when the article you linked to has CeramicSpeed’s chart that directly compares the Shimano 11-speed to the 12-speed AXS chain. The average difference @250W was 1.9W for Red AXS. And 1.2W vs. the Force AXS chain. And it should be noted that - though with extremely limited data - the efficiency gap closed with wear - with both the Red and Force ACS chains closing relative to the Shimano chains after just a couple hours. For whatever reason the Red chain only got 2 hours of break-in. But the Force AXS chain got 1.88W faster with a 13-hour break-in, which put it at only about half a Watt from the Shimano 11sp chain at 13 hours. Who knows where they’re at at 40 hours? So the article’s speculation about SRAM’s tighter tolerances might be valid. Maybe SRAM chains just need some break-in period to loosen up a little and let the lube do its thang.

The caveat that this is all includes CeramicSpeed’s coating, which could theoretically affect chains differently.

All in all, I don’t read it as being bad for SRAM. They come out as extremely durable, with a slight efficiency gap that could be plausibly explained to be situational.

I was slightly happy to read corroboration that KMC chains don’t hold immersion waxing for very long. I’ve been noticing that my immersion-waxed KMC X11SLs have been creaking after as little as 100 miles since coming out of the wax bath, e.g. sometimes within a single ride.

4

Anyone know the exact weight for 11 speed chain vs 12 speed?

5

Anyone know the exact weight for 11 speed chain vs 12 speed?

You’ll have to be more specific. Which 11sp vs. which 12sp?

6

What gets measured gets fixed - HP proverb

Lots of carbon frames were light and stiff, but were aero bricks…until tunnel testing revealed how slow they were and road frames suddenly got more aero.

Chains have typically been all about shifting performance (special plate designs), and weight (hollow pins, pierced side plates). It wasn’t until Friction Facts testing that we even knew you could save watts based on lube choice. Once someone (SRAM) starts losing sales because people feel their chains are slow, you can bet faster designs will be developed.

7

. Once someone (SRAM) starts losing sales because people feel their chains are slow, you can bet faster designs will be developed.

Well hopefully it’d be because the chains are actually slower, not because they feel they’re slower.

It’s not entirely clear that SRAM’s chains are slow. The data is not definitive.

And there was plenty of discussion about drivetrain efficiency before Friction Facts, including chain lube discussions. They just gave us a lot of great data to act on.

8

Why aren’t there any after market 12-speed AXS flattop chains to this day? Does SRAM own the patent to the flattop chain? Chances are chains from KMC, YBN, or Wippermann will be faster than SRAM Red if they’re allowed to make them.

9

Two part video here - very informative.

https://www.youtube.com/watch?v=uE7CqgRkD8c

GCN also did a video with the Friction Facts guy which was very informative.

10

Slower, but more durable. Train on SRAM, race on Shimano.

11

Slower, but more durable. Train on SRAM, race on Shimano.

Interesting.
German “Tour” nr. 3 of 2023 says exactly the opposite: Shimano and Campagnolo more durable than Sram.

12

Mollema “FUCKING SRAM!!!” - YouTube
.

13

. It’s not entirely clear that SRAM’s chains are slow. The data is not definitive.

What’s not definitive about it? Zero Friction Cycling came to the same conclusion.

14

. It’s not entirely clear that SRAM’s chains are slow. The data is not definitive.

What’s not definitive about it? Zero Friction Cycling came to the same conclusion.

Everyone seems to test new chains, e.g. Zero Friction ram it to just 13 hours in the efficiency test and took an average over that time. I posted above about one test where SRAM chains got faster with time, while the Shimano didn’t. This is after factory grease has been stripped. I’d just like to see someone run 'em out to a couple hundred hours to replicate or refute the one finding. Looking at instantaneous efficiency measurement at the end, not averaged over the window.

15

Not to mention SRAM uses small front rings and a tiny 10t cog in the rear. You can feel the friction through the pedals in that combo just pedalling. There’s good reason that pro’s request a 54/41 chainring combo effectively making SRAM 11 speed.

https://cyclingtips.com/2019/12/the-best-bicycle-chain-durability-and-efficiency-tested/#efficiency-comparison

They show chains treated the exact same have an increase of friction of 40% over Shimano 11 speed chains.

I would imagine two stock chains would have an even wider margin. Friction Facts original reports of 11 speed chains had Shimano chains 2 watts faster than Srams 11 speed (if I remember right) which would put their 12 speeds even slower. Likely widening out to 3-4 watts.

So in the end best case scenario is 2 watts and worst case 4 watts.

I know we are talking small numbers. But why are they moving in the wrong direction? Not to mention the AXS chain is twice as expensive.

I was looking at going Force AXS but I am no longer. Seems like a lot of $ for additional friction, and extra weight.

16

I assume you are talking about this graphic for the 13 hour test:
\

I’ve seen this in a couple of forums recently since Dylan’s video. It should be noted that this isn’t showing the chains themselves getting faster or slower over time, but is really showing a combination of the lubricant getting faster combined with the lubricant holding ability (or lack thereof) of the chains. When they run this test they run it until the friction hits a peak minimum break point and then begins to increase again. As this was all done with wax based lubricants, you see that the wax gets faster as it’s compressed, but then eventually gets slower as the solid lube is ultimately pushed out of the chain. The real takeaway should not be that X gets faster over time while Y gets slower but rather X holds wax lubricant longer.

In general we see that chains without fancy surface coatings hold lube better and longer, this is why SRAM second tier chains like the XO1 and Force test better than XX1 and red level chains, although SRAM has worked very hard to fix that. Though in this test the KMC Gold is a crazy outlier, my experience has been that coated KMC chains typically hold lube worse than most other brands, but most of my work has used the really fancy DLC coated ones.

We’ve built a rig with Purdue University which is at the moment the most advanced rig in the world to test this. We will be publishing stuff over the next year+ based on the learnings in the lab, and our goal is to ultimately help Purdue become to chain friction what Virginia Tech is to helmet testing, a fully independent lab focused on publishing for the public good… In the mean time we’re using it to not only compare lube and chain but to really try and understand the mechanisms involved here, like why does the friction reduce and then climb in these wax tests, what makes on surface or coating better than another, etc… What I can tell you from our learnings so far is that every chain and lubricant combination will go through a period of initial improvement over the first few hours and at some time (almost always less than 20 hours) it will hit a break point where things break down and friction begins to climb again.

This break point and climb is an indicator that you have metal on metal beginning to occur and that wear has begun, so you really want to avoid this regime of the curve.

If you catch the chain before this breakpoint and ‘reset’ it as Adam likes to say, you can repeat the same cycle over and over again hundreds of times with essentially no wear almost regardless of what chain you are talking about.

If I was after zero wear, I’d look at this chart and pick my chain and make a plan to ‘reset’ it before it hits the breakpoint, you’ll easily get 24-30k km from a chain treated like this.

If I was after the fastest chain, I’d look at this chart and buy the chain with the lowest peak minimum friction and then time it such that my event occurred in the Z amount of time before hitting the breakpoint

Screen Shot 2023-03-08 at 2.45.47 PM.png

17

on the chart you posted, do you know:

  1. was the test done using a bicycle drivetrain?
  2. were the chain ring and cog teeth totals the same for each chain?
  3. were the chain ring and cog for shimano congruent for each brand? (sram chain tested on sram cogs and rings; same for shimano.)

thx for whatever color you can provide on this.

18

When they run this test they run it until the friction hits a peak minimum break point and then begins to increase again.

Well maybe they do in other tests, but not this one?

Because friction was still decreasing in the last recorded sample for a bunch of the chains, including Force AXS and KMC 12S. Questionable if the 0.02W difference for Red AXS at hour 2 is really a change in direction or just noise. IIRC, the ones that didn’t run to 13 hours had some sort of test apparatus issue where they had to throw out the data.

So we don’t know what the “peak system efficiency” is or when it happens for combinations of chain and lubricant they didn’t run past the change-in-direction point. Nor do we know how long that peak efficiency might last for those chains.

I’m not criticizing the testers - I’m happy for any and all public info. Just pointing out the limitations as I understand them.

Edit: For a few chains, including Shimano, it looks like that change-of-direction to increasing friction happens around ~6.5 hours. So I wonder if they based their 13 hours on doubling that time period to safely capture the “valley” in the middle of the test period? But clearly that doesn’t apply to some newer chains?

19

So this isn’t my test or data and I honestly don’t know all the answers or details. This data comes from CeramicSpeed and was taken on the Jason Smith designed test machines at FrictionFacts which CeramicSpeed owns. This is just a chart I’ve seen on numerous forums recently discussing this whole ‘Shimano is fast but SRAM is more durable’ thing.

The testing is done in 2 steps, they use a full drivetrain test machine called the FLT, then then remove the chain at set time intervals and run it on a machine called the FTT which is much more accurate and capable of finding much smaller differences, but is essentially a fixed gear single speed setup that holds a very controlled tension between cog and chainring, this way you are just measuring chain or lube and minimizing non-chain related losses like pulleys and bearings.

I know from pictures that they use DA rings/cogs for the Shimano test and for sure they will have to use AXS rings and cogs due to the different roller diameter on AXS chains. I’m not sure what level rings/cogs used here nor am I sure what they use for non Shimano chains, though I assume they just use the same DA rings/cassette that is used with Shimano.

To answer Trail’s points, I’m not sure why the testing is done at these time intervals, but can assume that since the chain has to be removed to take the final data they do it this way to minimize the time and labor involved in the testing. Also remember, Ceramicspeed has all of their equipment and protocols designed around lubricant testing and development, so data sets like this are something they are throwing out there as an added service, but it’s not their focus and I think it’s fair to say that if you were designing a test to really look at specifics of the chains themselves you would do it differently. I imagine that the 13 hours is probably the norm as it captures the break point and pretty much all lubricant testing is done with DA chains as they test very fast, but are also extremely consistent in their manufacturing.

From our experience developing this new test machine with Purdue, I think this new machine will be able to better able to test for friction and continuous performance as it will allow for nearly the accuracy of the FTT machine, but with the continuous data readout of the FLT style machine. I think we will still need to develop test protocols that are separate for lubricant performance than for chain longevity or inherent chain friction, but this might be the first chance for a single machine to exist that can do it all.

I can say that we’ve found some really interesting curve shapes in terms of performance over time with some lubes hitting peak minimum quickly, some hitting it slowly, and wildly varied time spend in the trough. From that I’d say that the timing of the test in the chart is just way too coarse to catch much of this performance variability and ideally you probably want more like a minute by minute plotting of the friction to properly understand what’s happening.

20

let me answer my own question that i asked you: based on the picture of what i think is the chain efficiency tester the chain is used on the drivetrain made by the chain maker (or i assume the drivetrain the chain maker intends for its chain).

unfortunately, there is no mention of teeth totals or gear matching or whatever. i guess i wonder about protocol because the differences are a fraction of a watt. i wonder if older testing rigs are retrofitted to accept (say) XD drivers or if the testers just say fudge it and run the chain on an unoptimized cassette.

regrettably, our audience is programmed to take any test as better than no test, whether protocols be good or bad, unless the test displays obvious math errors. we’re less good at the rigor of protocols that ensure a fair and real world analysis.