This is not as if it never happened before :

https://www.theguardian.com/...ce2003.tourdefrance1

The problem : no front shifter

It was removed at Millar request - aero gain, I suppose - against the will of the team (as the mechanic perfectly knew what will happen.... and it happened).

Clutch solve this ? ..... well, apparently, no

It's going to be interesting to see what Trek does for the cobbles. I'd imagine they have to go 2x or run a catcher (or both).

i only know what i read on cyclingnews.

SRAM AXS derailleurs don't have clutches. they have a damper, that works well enough that a clutch is not needed. so, did it not work in this case? i don't know. what i read says he couldn't get his chain back on his bike, which tells me he wrapped the chain around something - either the BB or between the cassette and the frame, which means it wasn't a chain derailment, as you're thinking, but - if it's on a descent, which it was if i read it right - a high gear adjustment screw?

if it derailed off the front ring, yeah, that's troubling. but i'd like to know the circumstances first (as you might guess). i can't imagine that the wrong CR was used, or the wrong chain, or the wrong RD, but, before i blame the equipment i'd like to know what happened.

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Dan Empfield
aka Slowman

Saw that on TV : while riding downhill, he was putting its hand at crank level. It seems to me a front ring chain jump, but can't be sure.

Several articles (in france) talk about lack of front derailleur/chain guide, but they have no proof.

Degenkolb and the team made no comment, which IMO tend to confirm a 1x problem. IMO, if not an 1x problem they would have stated it clearly. Again, this is only my interpretation.

This remember me the David Millar / TdF 2003 Prologue event... but at this time, no damper, no clutch.

Personnally, i would feel better with a chain guide. Especially one mentioning wolves :-)
http://mynameiswayne.com/...ocross-vessel-build/

You are correct and it was off of the front ring lodged between the frame and ring. I was re-watching the finale 20km on the trainer and you could see it. He was trying to pull it out and couldn't. Degenkolb was visibly PISSED. I didn't see Stuyven's incident but Degenkolb mentioned it was the same failure that he had.

I wonder how many fails and race contention has to be lost until they go back.

That's what it looked like to me too. In fact the announcers thought he was slamming the front end of his bike down in frustration, but I think he was just desperately trying to dislodge the jam.

Jeez, how many times must the Miller incident from 16 YEARS AGO be brought up!?!

Of course Miller dropped his chain in 2003 using a crappy (by today's standards) chainring that probably had shift ramps on it! 1x technology has moved on people!!!

Fact is, chain drops happen, no matter what system you use. How many races have been lost from a missed FD shift & chain drop on a 2x system? Schleck come to mind?

All I know is, since I changed to 1X I have had a fraction of the number of chain drops that I used to have with FD shifts (I haven't I dropped a chain once on my etap 1x setup in the last 2 years of riding, and that's without any clutch/damper or chain catcher). And before people start shouting "but Shimano is perfect", my training partner with the latest Dura-Ace Di2 synchro-shift setup has dropped his chain 3x in our last 2 rides shifting the FD, which is a nightmare with synchro-shift as you can't shift the FD back and forth independently to try get the chainrings to re-engage, so it's a forced stop each time. Granted, maybe his FD setup is out, but still...

 
Your case is n=1
My case is n=1 (so, little interest to talk about it)

What would be more interesting would be some valid statistic, on reasonably large cohort.

Milan San Remo bring a large number of pro.
What was the % of chain jump on 2x ?
What was the % of chain jump on 1x ?

I don't know.

Too bad for 1x, during money time, it "seems" the % on 1x is much higher. But no formal proof.

We will see what happen on the other races.

If you look at the violent shifting in a chaotic pro tour spring classic, there is a great chance of a miss shift or dropped chain.

That the mechanics did not fit a chain catcher, just to be cautious knowing this is new system and all, is a mistake on their part.

Chain dropping is a possibility on any system, and and only a chain catcher can keep it close enough to shift back on very quickly.

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"Only those who risk going too far can possibly find out how far one can go." T.S. Elliot | Cycle2Tri.com
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I'm really surprised that we still see this chaindrop issue with 1x in the pro peloton. After all the bad news we got from Aqua Blue last year one would have thought the new AXS is bulletproof. I mean, I ride Eagle on my MTB and have never dropped a chain. Chain guard is really not necessary, even in the roughest trails.

Dege and Stuyven probably shell out massive watts so any comparision with us mortals will have to take into account that these guys push the limits of each system. But it's road. Something is not working right yet.

Miller was running a track ring on the front. No ramps, tall teeth.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

http://www.cyclingnews.com/...3-binckbank-classic/

Not to mention Pedersen now has a chain guide on his 1x at E3. Might as well have a FD at that point. Now every system has occasional failures, Sagan had a DI2 cable come loose on Friday at a critical moment and he was stuck in the 11, cost him the race. He also dropped a chain a few weeks ago as well and lost contact at a critical moment. I think it is important to understand why these failures happened. The failure at MSR was on the downhill and that is also the only time i have ever dropped chains with 1x. When you are in the big ring up front and 11 rear (or smallest cog) you have low tension. The narrow wide teeth and chain help prevent the chain from slapping around and falling off, a clutch RD eliminates this chain slap. My guess is the new sram RD does not apply proper tension, he hit a bump and it bounced off. I had the same thing happen back before i was using a clutch RD. The problem is the clutch RD introduces unwanted power loss that is not ideal. My guess is by Flanders they are all on 2x.

I think you are on to something. The most I've seen people drop 1x chains is in crits on smooth roads. I think there's some combination of the larger-ring/smaller-cog, and more "jumpy" power application (including sudden stoppage of crank movement) that is conducive to chain droppage.

So did Degenkolb ride a FD today? He did on Friday because he needed a "wider gearing" according to his mechanics :-)

Quite flat today:

I will bet a lot of money that we never again see JD on 1x.

The consensus it seems is that when you're pedaling at very high speed and start freewheeling drag from the freehub bearings causes the top of the chain to go ever so slack, and that makes it really easy to drop a chain.

Has anyone tested an AXS 1x with a 11S chainring?

Yes, I asked 3T because of the Torno. They said it is not compatible but they will make some changes. Whether that means change 11sp or to add a separate line, I don't know

OK, seems the problem is now clearly identified.

As well as the short terms solutions :
Degenkolb on 2x (with FD)
Pederson on 1x with chain guide

Any evidence that a "pure" solution (with no FD, no chain guide) can be found with some increased RD tension, clutch, .... without increasing measurably friction losses ?

What would such evidence look like? Some people say they ride with low tension, no clutch, and no FD, yet they never dropped a chain. Others say they drop chains even with a clutch, NW ring, and chain guide. There seem to be too many other variables to consider for standardized testing, such as pedaling style, types of surface roughness, chain length, cage length, cassette size, chain line, chainring tooth design, etc.

I'm pretty sure that statistically (measured on a large number of occurence), with existing SRAM AXS 1x system, chances to drop a chain with a FD or chain guide are much lower than without these additions.

And apparently Degenkolb, Pedersen, and some others pro .... think the same.

So, "What would such evidence look like? "
Probably some statistical validation, such as elite and pro using it regularly, without hating it.


But, before such proof, maybe just some reasonable testing in difficult situation of some innovative solution, avoiding the issue of low chain tension on "small cog" situation, such as during downhill ?

Do we have any companies making compatible chainrings yet? I am trying to run AXS with a SRM power meter.

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2024: Bevoman, Galveston, Alcatraz, Marble Falls, Santa Cruz

Just a general bump to this thread.

Anyone have any live or real world feedback?

Thanks,
Maurice