After a year of
rumors and speculation, SRAM's new drivetrain has finally appeared out in the wild, installed on several XC race bikes in Les Gets. As we expected, based on a patent that was granted last May, the derailleur uses a direct mount design that places the derailleur body more inboard compared to current SRAM derailleurs. That should help keep it safe from impacts, and the direct mount itself has the potential to add stiffness and stability to the system, improving overall shifting performance.
The design also looks like it would keep the derailleur in a more stationary position, something that would go a long way towards reducing the amount of unnecessary chain movement, and noise.
It's likely that the new derailleur will only be compatible with frames that can run a Universal Derailleur Hanger in order to ensure there's enough room for the mount to sandwich the frame's dropout. If that's the case, it seems like a very smart tactic on SRAM's part. The UDH standard has seen widespread acceptance, making it it easier to find a relatively inexpensive replacement derailleur hanger, and now those UDH-compatible bikes will likely be able to run this system too if riders decide to upgrade, or companies decide to spec it.
The derailleur is wireless and electronic, with the AXS battery tucked in between the two sides of the direct mount, and the power button situated in a recess in what looks like a composite plate on the side of the derailleur. It's hard to say for sure, but the pulley wheels look like they could be aluminum. If that's the case, it'd be a welcome upgrade from the plastic that's currently used.
Interestingly, the chain has the same 'Flattop' design SRAM uses for their road bike chains, which is said to add strength while still allowing for the correct width for a 12-speed cassette. The cassette looks to be all new as well, with the cogs pinned onto a carrier rather than the one-piece design currently used for XX1 cassettes.
There's no review coming tomorrow, but we'll try to get on one of these drivetrains as soon as possible - the potential for a quieter, more reliable shifting system is certainly very intriguing. The fact that SRAM's athletes are racing it at World Champs is typically a sign that it's getting closer to full production; this article will be updated if any release timeline is revealed.
One of my bikes is running a cassette with over 5000 miles of UK mud through it (though the last chain took a few crunchy miles and stern words to bed in)
Someone tell me otherwise but I used my Park chain checker and its exceeded ‘1.0’ in a time that I would not have even thought to check full stop. My boy rides SX and thats done the same though granted its SX….
Either way, thats my experience and it will not be replicated with more 12spd sram.
I'm doing this (maybe) from constant cleaning (chainpig) & lubing about every 2-3 rides (plus not shifting under loads) and this is in rough-ass Pisgah (eastern US / western NC) enduro and some pretty raw / rough DH conditions about 200-250 miles +/- per month and year round riding here. This also includes rides throughout east coast & Rocky Mountain regions annually - but maybe yr issues just the eternal radioactivity where you live (insert smile here).
cyclingtips.com/2019/08/bicycle-chain-wear-and-checking-for-it
This article discusses (among other things) the fact that several common checkers (any tool that measures inside-to-inside or outside-to-outside) throw a false reading on SRAM 12 speed chains due to SRAM's roller diameters being larger than normal:
"SRAM chains, and their oversized rollers, throw a spanner in the works. If you’re dealing with SRAM chains, then definitely get yourself a tool like the Pedro’s Chain Wear Checker II or Park Tool CC-4. They’ll work great with all other chains, too."
Perhaps you're on the lighter side of the weight spectrum. Perhaps you clean and lube extra fastidiously. I'm 100 kilos, lubricate regularly (follow Dumonde Tech's recs, just wait until you can hear it, then reapply, 3-4 rides usually), and wore a GX chain to 1.0% stretch in 400 miles in New England.
If you're getting 3000 miles out of a GX with it's lack of hardening treatments, then you're just not putting the same forces through it, and/or it's always insanely clean.
"SRAM chains are one clear exception to using these suggested tools. Most chains on the market start with a roller that’s 7.63-7.65mm in outside diameter. SRAM’s chains are larger — for example, rollers from a Red 22 chain are 7.69-7.70mm, while an Eagle 12-speed chain uses rollers that measure 7.72mm. And SRAM’s new Flat-Top chain as part of the Road AXS groups is larger again (7.90mm)."
I use a caliper.
prolly works for shimano lolz
I got one of those CC-4 checkers, but using it on 4 bikes with Sram drivetrains over a year now I can say that the difference to normal chain checkers is so tiny that it doesn't matter at all.
I have 3 different checkers in total and when the CC-4 say 0,5, so do my other normal 2 chain checkers.
So yeah, the CC-4 is nice, but not really that important for Sram chains.
Then there is also after market possibilities for older bikes since the UDH is an open standard to bike manufacturers so they can design a retrofit hanger for older models (within reason)
I just measured every chain in my house, including Shimano 8-speed, Shimano 10-speed, KMC 10-speed, and Eagle XO1 12-speed. All had roller diameters within +- 0.01mm of 7.70mm, with the Eagle measuring exactly 7.70mm.
If it was true that so many chains, not just the FlatTops, have oversized rollers, then they should not be recommending _any_ of the opposing-side-of-rollers style of checkers, since they won't work for a large number of new chains. Yet, while they did quickly mention the matching-side-of-rollers style are better, they continued to recommend the style that doesn't provide accurate measurements on dirty chains, and, according to them, all SRAM chains. That makes zero sense.
I mean, they state the following useless crap: "This digital chain wear checker proves that chains don’t wear evenly across their whole length. Additionally, dirt and grease (as seen here) can greatly impact the measurement." So in trying to prove that chains don't wear evenly, they use a dirty chain and also state that dirty chains can change measurements. The series of pictures showing differing measurements on the same proves _nothing_ about uneven wear because the chain is dirty, which definitely causes differing measurements. It just proves that those kind of checkers are wildly inaccurate unless used on a perfectly spotless chain (with rollers of a certain size and within a certain tolerance).
Currently on XX1 drivetrain with 4992.1km, almost 5000km(lol) and it seems it can go for a long time more, I bought a new XX1 chain last month, but my mechanic told me the chain is in very good condition and no need to replace it yet
I live on a island, with a lot of dust, rocks and sea all-round and Sram rocks,
Big respect for Sram.
And I was a Shimano guy.
I have exactly the same experiences with longevity of XX1 chain and cassettes (two bikes).
Maybe choosing more teeth at the chainring would help to wear all cogs at your XX1 cassettes more equally?
(considering that you write : "But if I used more of the cassette more often the XX1 would probably be the better choice")
I have an X01 & 2 GX cassettes on 3 rear wheels, the X01 brand new and my 1st one so I'm just assuming it'll be better than GX but about 1.5-1.75 yrs per GX cassette, give or take a bit (and lots of summer park riding so maybe less harsh overall?) those seem to last overly long. I'm actually wondiering if riding harder / steeper stuff means less overall wear (for me) that general trail / XC style - usually do bigass pulls much of the day then bomb down vs. constant gear switching all day as in XC. Dunno - I've not even tried Shimano in a decade, maybe I should check it out.
It's the cheaper chains that don't last. Lack of hardening on the pins is the big thing. GX gets hardened plates only, which maybe exacerbates the pin wear. NX and lower I think get hardened nothing, might actually be better than GX...
It's not really gear switching that wears the chain, it's just pedaling and dirt. A bad shift might break it, but doesn't really add much wear-wise.
Def try Shimano, I know lots of people beating the shit out of SLX and XT 12-speed and that stuff takes it well. The lever action is also way lighter than the past couple generation, which is super nice. I run SLX shifter & mech with GX cassette and XO1 chain, and race face ring (104 bcd for bash guard FTW!), works awesome.
However I don't support it, imo it's unnecessary time and effort trying to refine derailleur technology when the focus should be on gearbox style drivetrains, dérailleurs shift perfectly fine now and no one wants to spend thousands on a frame all for the latest dérailleurs to not be compatible...it's ridiculously unnecessary...sure it may be be better on paper, but I think most would rather know they can keep using the latest dérailleurs on their 10k super bike rather than have a 2% increase in shift performance and have to buy a new frame. Better sure, but nobody asked for it and nobody needs it.
If so how the heck does a clutch save a frame when the RD is slammed into a rock?
Anecdotal evidence but I haven't yet seen someone break a 12-speed hanger before replacing their derailleur.
This is the internet. There's a pretty clear record of what you said. Perhaps you misspoke. But it certainly was a general statement about hangers, which is untrue.
After seeing you whine about the down votes, I added one to the tally. I really do feel like I've accomplished something.
This design looks like it involves the axle, and if you break the frame there, well, I suspect other "bad things" happened that day...
As I said, new hanger, everything was fine. Still riding that derailleur (Eagle X01). But I guess I was babying my bike that day...
Your experiences are also proving what others have said: that _some_ hangers are too strong and break mechs before the hanger breaks. Run with that instead of just whining about being picked on for being a hypocrite.
If you keep breaking mechs, maybe try scoring your hanger with a dremel or such. In the 7 speed era (and earlier), when replaceable hangers were rare, mech bolts were designed with a thin section in order to break away upon a large impact, in order to save the hanger and the mech. Worked reasonably well, similar concept might work for someone with a too-strong hanger.
If you never broke/wore-out a front mech on an MTB, you didn't ride enough or enough trails.. Every one I've ever had eventually wore through one of both of the plates from the chain rubbing against it and scraping dirt and muck along.
*Riding my gravel bike parallel to some railroad tracks and a piece of rebar hooked my spokes, Wrapped around my wheel, and jammed in the derailleur. I was able to bend the cage back.
**My GX derailleur felt really sloppy, so I bought an X01 to replacement. No change in shifting performance, so I have a spare now
www.mtbr.com/threads/attn-all-axs-drivetrain-owners.1207581
Could link to the reliability of the parallelogram.
No axs of mech rear mech I’ve worked on has had a clutch problem. They just work. Maybe the chain slap isn’t a derailleur problem but specific to some bikes
that first bike is a supercaliber that DOESNT run a UDH in its current form....
That said, can hardly wait to buy one!
Also, we all knew that the open-source UDH was NOT going to be a free-lunch. SRAM is pretty smart in trying to get everyone to adopt to this all-new open-source standard...only to then drop products that are patent protected that other manufacturers cannot adopt. Making their original UDH mostly proprietary other than for older tech competitor parts. Very smart. Sneaky. But smart none-the-less.
Theyre basically the same as plastic ones, but worse
But, I'm sure they can figure something out for the next gen.
Also, Seth's bike hit the battery quite a bit, would likely still hit even with the post slightly out like 10-15mm.
That said, Shimano 11 speed rear derailleurs were waaaaay more durable than the 12 speed ones. Hopefully they don't chase SRAM further into making stuff with more features and less reliability.
Not everyone rides the same conditions
www.youtube.com/watch?v=BeOS9pG6vjU