Campagnolo 12 and SRAM AXS compatibility

[yinzerniner]

Originally Posted by jpritchet74

There was a "chain test" on cyclingtips sometime in the last couple of years

https://cyclingtips.com/2019/12/the-...ciency-tested/

Cyclingtips also had a podcast about that article, and one of my biggest takeaways was that the SRAM 12s chains lasted a LONG TIME, but they would wear out chainrings and cassettes more rapidly.

I would rather replace chains instead of chainrings and cassettes.

Your takeaway is flawed. If a chain lasts longer then it lessens the amount of cassette and chainring wear.

Cassette and chainring teeth wear comes mostly from elongation of the chain. Elongation of the chain comes from the pin, plate and roller wear.

SRAM 12s chains are said to have very good tolerances and great wear characteristics, however their tight tolerances also lend them to be slightly less efficient than other chains. In other words, even though the tolerances are tight and the chains wear very slowly possibly due to construction and coatings that same tightness and coating combo could make it harder for good lubrication to stay in the chain.
Operative quote:

And so it’s not hard to imagine that a chain with looser interfaces, although not as durable, could prove to be more efficient.

[Dave]

One little appreciated fact is that some chains elongate very little and show little increase in length (pitch), but plenty of roller and side clearance wear. A Campy 10 chain that I deliberately used for 6,000 miles did this and wore out the two most used sprockets.

Elongation wasn't even 0.25%, but roller and side wear was huge. Most of the roller wear was on the hole in the roller.

AXS users are seeing the same thing. They see little elongation and don't change a chain, then find worn out sprockets when a new chain is installed. I keep at least 4 chains in a rotation per cassette, so I'll never have new-chain skip.

[yinzerniner]

Originally Posted by Dave

One little appreciated fact is that some chains elongate very little and show little increase in length (pitch), but plenty of roller and side clearance wear. A Campy 10 chain that I deliberately used for 6,000 miles did this and wore out the two most used sprockets.

Elongation wasn't even 0.25%, but roller and side wear was huge. Most of the roller wear was on the hole in the roller.

This doesn't seem correct - roller wear shouldn't effect sprocket wear.
See article below with quote from Adam Kerin of Zero Friction Cycling:

The reasons for this discrepancy are down to roller tolerances and roller wear. The fact that some chains start life with looser rollers than others is not news. However, in what’s arguably new information to everyone in the drivetrain space, Kerin found that some chains had rollers wear at a far higher rate in proportion to the pins and inner links. And as mentioned before, the cog’s teeth don’t care about these discrepancies, rather it’s simply the distance between the rollers under load that really matters.

https://cyclingtips.com/2019/08/bicy...ecking-for-it/

Originally Posted by Dave

AXS users are seeing the same thing. They see little elongation and don't change a chain, then find worn out sprockets when a new chain is installed. I keep at least 4 chains in a rotation per cassette, so I'll never have new-chain skip.

What AXS users are reporting chainrings or cassettes wearing out before chains? Other than a single user at weightweenies with two posts I've never seen any indication that the AXS chains are causing premature wear on other components.
https://weightweenies.starbike.com/f...rt=15#p1738770

And you've pushed this narrative before without any evidence, only conjecture:
https://forums.thepaceline.net/showt...49#post3029449

While there will be some natural wear on chainrings and cassettes just from the direct contact as long as a good lube is used and the chain is cleaned and relubed regularly it shouldn't cause premature wear. If the chain is stretched, regularly dirty or a poor lube is used that would cause premature wear.
Quote from same CT article above:

Remember those .5% and .75% suggested replacement points? Well, unfortunately, chain elongation is not the only cause of cog wear — pure metal-on-metal abrasion is a major cause, too.

Myself and countless others have experienced it where a chain may only be slightly worn, but due to a poor choice of lube and a lack of basic maintenance the chain has abraded through a cassette. There is plenty of truth to the old saying that a clean bike is a happy one.

In Kerin’s chain lube testing, he discovered huge differences in cog wear as the direct result of chain lube choice. Some of the poorer-performing chain lubes, such as White Lightning Epic Ride, would see the cogs abraded beyond re-use by the time a chain measured .5% wear. Meanwhile, good wax-based lubes would cause almost no measurable wear to the cogs with the same chain elongation.

Generally speaking, for 10-, 11- and 12-speed drivetrain users, replace your chain when it measures .5%, and you’ll be fine with re-using the existing cassette and chainrings. And you should get three chains to that one cassette, and perhaps as many as six chains to the chainrings. Wait till the chain measures .75% and you’ll likely need at least a new cassette, too.

If anything people marvel at how long chains, cassettes and chainrings last on AXS with minimal fuss.
https://weightweenies.starbike.com/f...p?f=3&t=165855
https://www.trainerroad.com/forum/t/...hains/69626/13
https://weightweenies.starbike.com/f...60556#p1568522
https://forums.thepaceline.net/showthread.php?t=277520

Personally I still have my original Red AXS chain which was ridden for roughly 2500 miles with regular cleaning and lubed with Squirt, then later lubed with Silca Synergetic and ridden about 4000 miles, and it shows less than .25 wear using the Pedros chain checker plus 3 point tool. That's now my emergency backup chain as I switched to waxing, and the new Red and Force chains I've used in rotation on my main ride have been ridden roughly 3k miles each and show no elongation using the Pedros tool. And still on the same Red AXS cassette with zero shifting issues nor noticeable tooth wear.

[Dave]

@Yerzernier. As a mechanical engineer, I wanted to verify the contention that ONLY excessive elongation will cause new-chain skip. I proved that idea to be false. My Campy chain with 6,000 miles on it had about 1/4 of the allowable 0.5% elongation, but my new cassette had two prematurely worn sprockets. Campy recommends a caliper reading that combines elongation and roller wear, but most of the increased length is roller wear.

Alternating the use of 3-5 chains is the smart way to maximize sprocket and chain ring life.

I measure both total length elongation and the increase in roller spacing, separately.

[jwest]

Originally Posted by Blown Reek

While moving some wheelsets between bikes last night, I realized that I installed a Super Record 12 wheel on one of my bikes with Red AXS. My initial frustration was replaced with curiosity when everything seemed to shift smoothly, so I left it. I took out that bike for a 40-mile ride today, and everything worked perfectly. SRAM Red cranks (48/35), SRAM flat top chain, and a Super Record 12 cassette (11-29) all had zero compatibility issues.

So cool to have found this thread. I was about to just try it but now I'm just going to plan on how to best implement it! I mostly have campy gear. several road bikes but all sram 12 axs on my mtn bikes. I recently got a great deal on red axs road and have found to LOVE it on the gravel bike I built up from a last generation Kona Major Jake but with a ROTOR power meter which means I can run almost anything you can dream up for gearing on the crank from 1x using mtb rings, like think 26-34 tooth choices! or their double ring down to a 30/46.

On the ROTOR interface you can also use an EKAR drivetrain by way of the rotor 5 arm 110BCD spider with a RATIO UK 13s ring, choosing from 34,36,38,40,42 etc. When combined with the EKAR 9-36 or 10-44, it's a hufe range of personal choice available.

On the SRAM/Campy route, I didn't like that the RED cassette only goes to 33, but that the Force is nearly 100g heavier. I have not checked yet but a Super Record -34 is probably pretty similar to the RED in weight.

I have tested a 30 ring with the 10-33 and the high end just wasn't enough for fast sections where you'd get over 25 mph and want to keep rpm below 100 for stability. I could see a higher rpm for a 100m sprint finish but bridging to a break or a slight descent hard drive would just get silly with 30x10.

At 34x10 I had a nice stable and maintainable 90 rpm at around 25 mph I think it was and that felt good on smooth gravel. Again, on a paved section it wouldn't be quite enough for any useful duration.

I REALLY prefer close ratio cassettes and while EKAR does well with the first 6 cogs, as does RED, I'm looking at the best way to do a 2x with a 30/46 but then smallest cassette possible and the campy SR -34 might help just enough for most routes.

I'm in WA state US so we have too many 30minutue to 1 hour climbs to ignore efficient and/or comfortable climb gearing.

[kierownik]

Has anyone had experience using Sram Red Etap AXS front and rear derailleurs and shifters with Campy chainset, cassette and rim brakes?

Hoping this combo will work OK without needing to upgrade many other components.

[Dave]

SRAM AXS works great with Campy 12 48/32 cranks, The AXS chain works fine with the cassette and chain rings. I didn't use my Campy 11-34 cassette long enough to fully evaluate shifting with AXS rear derailleur, but it wasn't bad. I wanted a 36 large sprocket. I used my SRAM AXS 10-36 cassette with my Campy 12 drivetrain and it worked fine, too.

The SRAM FD may not go high enough to use with chain rings over a 50, unless your frame uses a clamp on adapter.

Red, force and rival parts should all work the same.

[kierownik]

That’s great to hear. I do have a steel frame with clamp on adapter for the FD, so hopefully this works out with my 52/36 Chorus 12 cranks.

The Red etap RD says the max sprocket is 33, so I’m guessing I’d at least need to change my cassette to a 11-32 from 11-34.

[Hilltopperny]

Originally Posted by kierownik

That’s great to hear. I do have a steel frame with clamp on adapter for the FD, so hopefully this works out with my 52/36 Chorus 12 cranks.

The Red etap RD says the max sprocket is 33, so I’m guessing I’d at least need to change my cassette to a 11-32 from 11-34.

The AXS RD will shift 11-34 without any issues. I have tried it with the D1 Force that was rated 33t. Word on the street is they will shift up to a 36t rear!

[Dave]

The 33t capacity RD will indeed work with a 10-36 cassette, but don't overdo the B gap.

Using a 52/36 crank creates an extremely tall top gear. A 48/32 is a much better choice, since a 48/10 is like a 53/11. I use a 46/30 Shimano GRX crank. The top gear is like a 50/11.

The same RD with a Wolf Tooth road link and longer chain will shift a 10-44 cassette, except for the big/big. Sequential mode will prevent that combo from being used, but I dislike the unexpected FD shifts with sequential mode. I use extended range RD cages.

[kierownik]

Thanks for the input. Good info!

Any experience with Sram Red AXS etap levers with Campy Chorus 12 or Record 12 rim brakes? Hoping to keep my campy brakes.

[Grifter23]

Here is my experience with Campy Chorus cable 12 spd, Ekar, SRAM for bikepacking. I am running older long calipers brakes with 43mm GravelKings, no disks. The front Chorus derailleur says a max of 35mm tire so the tire doesn’t rub. So far I can get a 43mm to clear without rubbing. I am running a Chorus 48/32 compact crank. Start with a 11/34 Chorus cassette, rear Record hub, using KMC 12 speed chain. Everything worked fine, then I needed more gearing. So I switched to a White Industries MI5 rear hub, and switch to a SRAM gravel cassette 10/36. Still using 12 spd Chorus derailleurs front and rear. 130mm spacing on the rear hub.

Then again I needed more gearing. So I switched to a SRAM 10/44 rear 12 spd cassette, put on a Ekar 13 speed rear derailleur. I pulled off the KMC 12 speed chain and went with a Chorus 12 spd chain because it was 5.1mm to KMC 5.2mm. The chain is close inside the Ekar rear derailleur on the sides, but so far nothing is rubbing. So far this setup is working perfectly. It does feel like the spring is stiffer in the Ekar and it took a little bit to get used to pushing the paddles a little harder.. I will update late if anything goes wrong.

[gorkypl]

Originally Posted by Grifter23

Then again I needed more gearing. So I switched to a SRAM 10/44 rear 12 spd cassette, put on a Ekar 13 speed rear derailleur. I pulled off the KMC 12 speed chain and went with a Chorus 12 spd chain because it was 5.1mm to KMC 5.2mm. The chain is close inside the Ekar rear derailleur on the sides, but so far nothing is rubbing. So far this setup is working perfectly. It does feel like the spring is stiffer in the Ekar and it took a little bit to get used to pushing the paddles a little harder.. I will update late if anything goes wrong.

So you are saying Ekar rd works with Chorus 12 shifters and Sram 12 cassette? Wow!

[Dave]

Originally Posted by kierownik

Thanks for the input. Good info!

Any experience with Sram Red AXS etap levers with Campy Chorus 12 or Record 12 rim brakes? Hoping to keep my campy brakes.

SRAM etap levers works fine with Campy rims brakes.

[Gwerziou]

Originally Posted by gorkypl

So you are saying Ekar rd works with Chorus 12 shifters and Sram 12 cassette? Wow!

This would be unexpected and intensely interesting, can anyone confirm this?