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SRAM RED eTap AXS 12-speed wireless road bike group – Complete tech overview

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specsSRAM went 12 speed a while ago, but there's still no mechanical version for road or gravel bikes.
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The all-new SRAM RED eTap AXS road bike group with 12-speed wireless electronic shifting takes everything they learned from the original eTap group and makes it better. Actually, it takes everything they learned from all of their road groups -design, shifting, noise, and more- and makes that better, too. The new RED group is a complete rethink of what road bike drivetrains should be, and the addition of a cog is only the beginning!

First, the wee bit of bad news. None of the original Red eTap components are compatible with this new group, for a number of reasons – geometry of the derailleurs, new electronic chips, another cog, new chain, etc., the list goes on as you’ll see.

Red eTap came out about three years ago, and it’s great. But there have been big changes in the road riding market in that time, and electronics continued their steady march of improvement. So they made a new group. All new. The only thing that’s the same is the battery and the hydraulic brake master cylinders in the hoods. OK, and the Blip buttons. But that’s it. Which means all new components, but also new chainring sizes and a new philosophy on gearing…

Mechanical improvements & new gear combos

why did SRAM change the chainring sizes and gear combinations on their new RED 12 speed road bike group

If we’re being honest, it’s kinda surprising that no one’s rethought chainring sizes for decades. Yes, we’ve added compact and 1x, but the standard road bike has used the same basic gearing combos for a long, long time. Yet, the ways we ride and our knowledge of how our bodies work has changed dramatically. And now, on this group, so does the gearing.

The derailleurs are new, with only one version each for front and rear. Which means only one cage length that works on any of their gear combos. To do this, they took some of the range from the front and moved it to the cassette. The effect is that you can stay in the same chainring longer, and steps between gears in the back are more consistent. Before, the typical combos with traditional chainrings are:

  • 53/39 with 11-25 cassette
  • 52/36 with 11-28 cassette
  • 50/34 with 11-32 cassette

what are the new chainring sizes and gear combos for sram red

The new X-Range gearing changes that up, keeping a consistent 13-tooth difference between small and large chainrings for all options. The new combos are:

  • 50/37 with 10-26 cassette
  • 48/35 with 10-28 cassette
  • 46/33 with 10-33 cassette

what are the new chainring sizes and gear combos for sram red

These new combos offer range that’s essentially the same or greater than the traditional gearing it replaces, thanks in large part to the new 10-tooth small cog on the cassette. The range is equivalent to 260%, 280% and 330%, respectively.

what are the 2019 sram red cassette options and tooth counts

On the small end of the cassette, they keep 1-tooth jumps for longer than the equivalent standard cassette, which means it’s easier to find the right cadence in more of the cassette. It also means you’re likely to stay in the big ring longer.

So, what about efficiency loss with going to a smaller cog in the back? They say that, first, you’d be hard pressed to measure the difference. And second, you’d be harder pressed to actually notice it on the bike. Technically, yes, a smaller diameter bend in the chain will have more friction. But, SRAM’s Road Drivetrain product managers explain (and can back it up with data) that when you have that smaller radius, chain tension is higher, which actually increases efficiency. And since you probably can’t really feel it on the bike, and since you’re more likely to stay in the big chainring, and since the entire gear system shrinks in physical size by about 10% and saves weight, and since the gear range as a whole is probably more usable and enjoyable, you end up with an overall win. Ultimately, that’s what it’s all about for SRAM – they want to improve the riding experience. Plus, really, how often are any of us really riding in the smallest cog?

what are the new chainring sizes for SRAM 12 speed cranksets

Oh, and when you’re in the small chainring, the 10-tooth cog is electronically blocked out, so you can’t run a small-small combo. It’s done to prevent the chain from trying to hit the pickup points on the big ring as it’s completely cross chained. Which actually let SRAM better optimize the entire system around real-world useable gears, not a small-small combo that no one should be riding in anyway.

A few terms you should know

As usual, the new SRAM group comes with branding, so here’s the new terms for the features and parts in the group:

  • AXS – Refers to the new digital family of wireless/electronic components that will all work together. Check our AXS overview story for everything you need to know on that. Basically, anything with the AXS logo can communicate with each other.
  • X-Range – The name for this entire new gearing concept.
  • Orbit Chain Management – A new fluid clutch to improve chain retention.
  • AXS app – Lets you customize the setup and integrate cross-category components, check riding time, battery level, how many times you’ve shifted, and when you’re due for service.
  • FlatTop – The new, narrower chain that’s also stronger, quieter and more durable. It’s not backwards compatible (nor is any other component), everything here is designed as a system to maximize performance.

2019 SRAM RED Cranks

why did SRAM change the chainring sizes and gear combinations on their new RED 12 speed road bike group

The new RED cranksets will come in 2x, 1x and aero variants, with the latter aimed at TT and triathlon bikes and also being available only in 1x designs as 48 and 50 tooth options. Smaller tooth counts will be available, but they’ll look like regular 1x chainrings, not aero.

The new 2x chainrings are machined from a single piece of metal, and that’s the same for the Quarq power meter versions. They wanted a fully integrated power meter, so yes, the power meter is fully integrated into the chainrings as a single piece. This makes it a lighter-weight powermeter system, and easier to upgrade to power. But, when you want to change your chainrings, you’ll be replacing your power meter, too. Fortunately…

why did SRAM change the chainring sizes and gear combinations on their new RED 12 speed road bike group

…the chainrings are shaped to improve durability, particularly keeping the teeth holding shape for longer. And they’re silver, so they’ll look newer for longer than the old black ones where the ano color would wear off. So, how long will they last? Probably three or more years, or tons of miles, but there are simply too many variables (conditions, how well you clean and maintain it, chain replacement schedule, etc.) for them to make numerical claims. They say you shouldn’t have to do it that often. And when they do, SRAM will give you 50% off a replacement powermeter chainring set and recycle the old one.

what are the new chainring sizes for SRAM 12 speed cranksets

New tooth profiles are designed to reduce noise, particularly in cross-chain situations. They also shift very crisply, something we’ll talk about more in our first ride review post.

1x12 road bike chainring and cassette option for SRAM red etap axs group works with their new Eagle AXS electronic wireless mountain bike group

For 1x, they’ll offer 36-50 tooth count options in two-tooth (even number) increments. The larger 48-50 tooth options use the completely integrated powermeter or direct-mount designs. The smaller 36-46 sizes bolt to a direct-mount spider (in a new Asymmetric 107bcd, available with or without a powermeter) using four T30 bolts, and the spider/power meter attaches to the crankset with eight T20 bolts, same as their D-Zero cranks. These new 4th generation X-Sync chainrings that have a slightly different tooth profile than Eagle. The goal was to reduce noise, and the angle of the chain is different because you’re running larger chainrings on the road, so the shaping for entry and exit had to be different. They say this along with the new chain results in a 50% improvement in component life. They’re working on a 52-tooth for their pro athletes, which may or may not make its way to the public.

1x12 road bike chainring and cassette option for SRAM red etap axs group works with their new Eagle AXS electronic wireless mountain bike group

That sleek looking Quarq power meter bit is merely a cover, the internals and function of that part are same as they ever were. Here’s what the TT cranks look like:

sram red 12-speed 1x chainring for TT time trial and triathlon has a built-in Quarq power meter

sram red 12-speed 1x chainring for TT time trial and triathlon has a built-in Quarq power meter

sram red 12-speed 1x chainring for TT time trial and triathlon has a built-in Quarq power meter

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

Back to the cranks: They rolled out their DUB system for mountain bikes about a year ago, and now it’s come to road bikes, too. So, only one spindle option, then find the right DUB bottom bracket to fit your frame. Except that they will have options for the few frames that can’t accept a DUB BB, but mostly they want you to go with the DUB setup for BSA, BB30, PF30, BBRight, PF30A, 386 and PF86.5.

The new SRAM X-Range Cassette

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

The cassette is new, too, and switches to their XDR mounting design. Which is, in all honesty, a far better system than the standard freehub body. It’s one piece, machined from steel like the prior Red level cassettes. Tooth profiles are refined, but the overall manufacturing process is the same. It keeps the elastomer Stealth Rings between cogs to silence shifts.

whats new or different about the 2019 SRAM eTap 12 speed road bike group

To fit 12 cogs into the same space as 11, they used a couple of design tweaks. First, the cogs are a bit thinner, but as strong and durable as the 11 speed cogs. Second, the actual overall width of the cassette is just a bit wider, which is possible because the smallest cog is now 10 teeth, so there’s just a bit more room next to the dropout (depending on the bike’s design, of course). Combined with a thinner chain, there’s room for that extra cog.

SRAM XDR XD Road freehub driver body for 12 speed road bikes
The smallest cogs hang off the end of the XDR driver body, letting them use smaller tooth counts than is possible on a traditional freehub body.

To make room for the 10-tooth cog, you’ll need to use the XDR freehub body, which is widely available on a number of hub brands. XDR is their road specific version of the XD driver that was introduced with the wide-range mountain bike groups years ago, and the difference is that they’re 1.85mm wider. This extra width is necessary to provide the right clearance for the cassette next to the spokes since road cogs aren’t as big and can’t dish like a 50-tooth MTB cog can.

new SRAM RED 12-speed cassette

Their main focus for development was 2x performance and endurance road bikes, which is why you see these tooth counts. Which means there’s room in the future for something like a 10-38 or 10-40 cassette for 1x gravel and cyclocross. But, in the meantime, the Eagle mountain bike cassette, though, is essentially a 10-42 with a 50-tooth bailout gear.

The smaller chainrings, along with the switch to their XDR freehub body and cassette, also let them reduce the minimum chainstay length to 405mm, down from 420mm, while still keeping proper chainline. It drops to just 395mm for 1x bikes. This is important for disc brake bikes, which originally required a longer chainstay length because they were using a 135mm wide hub standard (as opposed to 130mm for rim brake hubs). So this design allows the same shorter chainstay length as rim brake bikes enjoyed.

The new SRAM FlatTop Chain

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

To accommodate all of the gears in the system, they had to make the chain thinner. Which raised concerns about strength. By adding the material back at the top of the plate, as opposed to using the usual figure-eight shape, they gained back any strength that was lost to reducing the chain width. And it’s the same weight as the prior 11-speed chains.

The outer plates are thinner, but the overall proportions of plate thickness and internal space between the plates are all smaller now. Meaning this 12-speed chain is a lot thinner than the 11-speed one.

How much thinner? We’re working on that. But it got more narrower than the space between the cogs, so there’s actually more clearance between the chain and the cogs on either side of it, too, so it runs quieter. It’s a dedicated road chain, so it’s not compatible with their Eagle mountain bike groups. Why? Because these are designed to shift on the front, which their 1x MTB groups don’t need to do. Which means if you’re setting up a 1x bike with a mountain bike cassette, you’d use the Eagle 12-speed chain.

the new SRAM FlatTop 12-speed chain tech details and design overview

It also gets a hard chrome finish treatment, which improves its life by reducing wear by at least 50%. Put another way, it should last about 50% longer. And this also helps it reduce wear on the cassette, too, because as your chain deforms from wear, it starts to reshape the things it’s in contact with. Remember when shark tooth shaped chainrings meant they were really worn? That was caused by a worn-out chain being run well past its prime. So, when the chain lasts longer, the cassette and rings will, too.

New SRAM RED eTap AXS Shifters

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

Inside the shifters are faster chips, which means the whole system reacts more quickly to your shift inputs. The hood and handle shapes are similar to before, but the textures and paddle shape and size are more refined.

how does the new SRAM eTap AXS wireless electronic shifting road bike group work

how does the new SRAM eTap AXS wireless electronic shifting road bike group work

Reach adjust and bleed ports are up top, and the CR2032 coin cell battery that powers the wireless shifter now sits on the bottom of the lever body.

what does the small button do on the inside of a SRAM eTap shifter

The pairing button is still on the backside of the paddle and is used to connect the shifters to the derailleurs during setup. Once that’s done, they can be used to trim the rear derailleur, and turn Enhanced Mode on or off without having to use the AXS smartphone app…keep reading.

SRAM RED eTap AXS Front Derailleur

what size tire will fit next to the new SRAM RED eTap AXS front derailleur battery

Even with all the other news around this group, perhaps the biggest question we had was the FD’s battery-to-tire clearance. The original eTap front derailleur placed the battery far inboard, which limited its use for gravel bikes because it could potentially rub on anything bigger than a 40. Now, clearance is better by 2.5mm, which means you can now run tires that are 5mm wider overall. They say it’s good for a 700×42 with 415mm chainstays. Want bigger tires? Get a bike with longer chainstays or go 1x.

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

Now for the rest. There are geometry changes to the cage, made to accommodate the smaller gear combos, but they’ll still fit on existing road bikes using existing mounting standards. They shift a little quicker, too, because they have faster chips inside them, and the motor and gear units inside are new and faster, too. But not so fast that they’ll throw the chain.

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

More important than speed is accuracy, and SRAM Road PM Paul Cantor says it’s able to position itself more precisely based on where the chain is on the cassette, so there’s less chance the chain will rub, so it’s quieter.

SRAM RED eTap AXS Rear Derailleur

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

The new eTap AXS rear derailleur becomes 1x compatible thanks to an integrated motion control system. It’s a fluid damper, serving the same purpose as a clutch on mountain bike derailleurs, but does so without a mechanical clutch. Called Orbit, it’s essentially a speed sensitive damping system for the derailleur cage, and you can check out our patent coverage of the design right here.

SRAM Orbit hydraulic derailleur clutch

Inside is a vane (think “paddle”) that moves through the fluid as the cage is pulled forward. So if you hit a big bump and the chain jumps and pulls the cage forward quickly, the fluid will resist that rapid movement of the vane. But the slow movement of a shift won’t create fluid drag, so it doesn’t sap power from the battery. Think of dragging your open hand through water – go slow and it’s easy, try to go fast and you feel a lot more resistance. They’re not calling it a clutch, but it basically does the same thing and will allow this system to work well in a 1x system on gravel and cyclocross bikes.

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

Side note: If you’re running a 1x system, the rear derailleur will actually shift a fraction of a second quicker because it’s not having to double check against front derailleur position.

There’s only one model now, no short- or long-cage options. Just one, and its length sits between short and long. Because the tooth count jumps are the same between all three chainring combos, it works, regardless of which cassette you pair with which chainrings. So, even though the pairings are designed for specific use cases, you can still mix and match.

Blips & Blip Box

new smaller blip box for SRAM eTap AXS
Photo: SRAM

The Blip buttons themselves carry over unchanged, but the Blip Ports on the drop bar shifters are now independently assignable from the lever shifters. So, just because you have a Blip button plugged into the left shifter doesn’t mean it’s doing the same things as the left shift paddle…it could be set to shift the other direction, activate a dropper seatpost, or something else in the future.

The new Blip Box is about 50% smaller than the original, and there’ll be a new Zipp Vuka Aero cockpit (shown in photo above) that hides it inside a fairing for a cleaner, sleeker and more aero package. They say OEM partners are also looking at new ways to hide and integrate the Blip Box inside the frame, stem or aero bar…look for that in 2020 or 2021 models.

New rotors, same brakes

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

For traditionalists, they’ll carry over the mechanical rim brakes, and will have new eTap AXS shifters available with mechanical cable pulling levers. For the hydraulic brakes, the only real change is at the rotors, and even there it’s mainly cosmetic. The braking surface part of the rotor is the same, but there’s a new carrier that’s way better looking.

SRAM RED eTap AXS 12-speed road bike group with wireless electronic shifting - full technical details and specs

They say the vents and shaping were not done for heat management, but to our eyes it does look like it should provide more cooling surface area.

Tying it all together with the AXS app

how to use the SRAM axs app to set up wireless shifting on road and mountain bikes

For the full overview of how the new SRAM AXS family of components works together, read our AXS tech post. Here’s the summary recap specific to the road group. The new RED eTap AXS group doesn’t require you to use the app to ride it, but you’ll get more out of it if you do. Through the app, you can turn on “Enhanced Mode” that offers two different versions of auto-shifting: Sequential and Compensating.

how to turn on enhanced mode for SRAM eTap AXS road group

Sequential mode will automatically shift the front derailleur as you move through the cassette to optimize the cadence steps. Compensating mode will, when you shift the front, automatically shift your rear derailleur 1-2 shifts in the appropriate direction, also to maintain a smooth cadence step. The idea is to keep you focused on the ride and let the computer figure out the best gear combo for you. You’ll need to input which cassette and chainring combos you’re using so it knows how to perform, but after it’s all set, you can simply turn it on or off using the trim buttons on the shift paddles…no need to pull out the app.

The app also has a mode control that lets you assign the shifters to different functions, swap which side does what, and turn the multi-shift on and off. Multi-shift is when you just hold down the paddle and it shifts through multiple gears. You can choose how many it’ll shift through at a time, limiting it to just 2 or 3 cogs, or letting it rip through the entire cassette if you hold it down long enough.

When is it available? What else? What’s next?

complete sram red etap axs drivetrain group tech details and specs

It’s available now. They wanted to have product ready at launch, so production has been running and things are shipping from the factory to be in the market today. Parts will be ready for aftermarket first, with limited availability on complete road bikes, too. They partnered with 15 brands to have bikes on sales throughout the world (we’ll have a post showing most of them later today). More complete bikes will follow in a couple months.

Force eTap AXS coming in April 2019, but they’re holding the details on that group until it launches. As for this RED group, we’ll have pricing and actual weights in our first ride review (links below).

What about mechanical groups? Will they see these same gearing and functional changes? We asked but haven’t received an answer yet. But our guess is yes, it’s almost certain that this new design will roll out to the mechanical shifting groups.

Important: Make sure you upgrade your indoor trainer to one of these new 12-speed cassettes and XDR driver body if you plan on using your bike on a trainer. They say Wahoo will have a driver body ready for their KICKR trainer very soon, and other trainer companies were alerted a while ago.

Want more? Here’s all of our tech stories from the SRAM AXS launch event:

SRAM.com

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Fred
Fred
5 years ago

210mm discs? sounds big for road, the carrier is indeed better looking, the more black the better

greg
greg
5 years ago
Reply to  Fred

that looks like the max size for the lock cap, not the actual size of the rotor. Likely 140 on the tarmac pictured

tom jones
tom jones
5 years ago

For some, I’m sure this is great news. For me, I ride bikes to get away from computers and screens and smartphones and all of that. I’m quite sure there are many others that do the same. I know I still can for now, but how about in ten years? Will all of this stuff trickle down to the point where even moderately priced bikes will be equipped with all of these “must have” features? Believe me, I am stock piling parts for my cable operated “obsolete” 10 speed drivetrains. Even looking for 1 1/8 inch suspension forks, since those are apparently becoming a thing of the past… Been around long enough and have learned how to play the game that the industry has created.

Jan Saj
Jan Saj
5 years ago
Reply to  tom jones

Old Man Yells At Cloud

Aaron
Aaron
5 years ago
Reply to  tom jones

Yes. I wish I had just spent all my money stocking up on Campagnolo SR from around 2000.
It would have been a much better investment than the stock market… NOS Carbon Record seatpost? $450?

Dolan Halbrook
Dolan Halbrook
5 years ago
Reply to  tom jones

I hear ya. Some days i feel like archeologists a million years from now will wonder why we worshipped the lowly CR2032 battery, given how many of those damn things we discard. As cool as electronic shifting is, I’ll stick with my DA 9000 mechanical until it dies. Hydro brakes, on the other hand, are the lord’s work.

Bob
Bob
5 years ago

their rotors look like a cheap crappy non-functional knock-off of shimano’s.

Tiago Silva
Tiago Silva
5 years ago

what abou rim brakes?

hleogr
5 years ago
Reply to  Tiago Silva

Also available for rim brake

matt
matt
5 years ago

I’m really intrigued by the concept of this, but it all hinges on whether or not SRAM were able to make a decent front derailleur. Also, I know it’s all just ad copy, but I don’t think their gearing options have as much to do with learning about how bodies work, or whatever, as they do with making you use their proprietary freehub design. Though the knees of the world will probably be happier with smaller chainring options. And while I’m griping like an old fart, can we just not with clutches on road drivetrains?

Dinger
Dinger
5 years ago
Reply to  matt

The Yaw F/D’s are equal to Shimano in shift performance and superior in that they do away with the need for a trim index in the shifter. I used Shimano F/D’s on my SRAM groupset before the came out. I never missed them after these came out.

Mark
Mark
5 years ago
Reply to  matt

It’s not strictly a clutch, but really a damper. Yeah, it’s not necessary for just road riding, but since they don’t have a gravel derailleur, this is supposed to do double duty. And I guess it doesn’t have as much friction as the clutch, which they’re retaining on the MTB group. So you can choose whether you want a clutch or damper.

Speaking of how much friction you get from the damper or clutch, in the future I expect to see the damper having an electronic valve on it so it can have much higher damping when an accelerometer sees that there’s a lot of bouncing around, and no damping when shifting. Maybe then the MTB group will switch over to the damper.

If you really dislike having the damper, I’m sure you can drain the fluid out of it somehow. Or if you want more damping, change to a heavier fluid, just like with forks.

TheStansMonster
TheStansMonster
5 years ago
Reply to  matt

Why not clutch/damper on road bikes? With electronic shifting there is literally no downside. Not all roads are smooth.

J-DOG
J-DOG
5 years ago

These are some exciting developments. SRAM clearly has done their homework and I look forward to getting some time riding these new technologies. Hear that sound?? That’s Shimano scrambling to stay relevant.

Joe
Joe
5 years ago

How do I wash the bike?

mateo
mateo
5 years ago
Reply to  Joe

The whole thing is IP69K certified. Wash it however you want.

Fred Gravelly
Fred Gravelly
5 years ago
Reply to  Joe

Dry cleaning

mudrook
mudrook
5 years ago

So after using Shimano’s freehub standard for years, Sram is going their own way with XDR. The advantages of a 10 tooth cog are undeniable. But Shimano is stubborn, and loathe to use someone else’s standard. We’ll see how long they hold out.

Dinger
Dinger
5 years ago
Reply to  mudrook

“The advantages of a 10 tooth cog are undeniable.”

What are they? I can’t think of any.

“But, SRAM’s Road Drivetrain product managers explain (and can back it up with data) that when you have that smaller radius, chain tension is higher, which actually increases efficiency.”

I’d like to see this data.

Aaron
Aaron
5 years ago
Reply to  Dinger

Yeah.. pretty sure physics disagrees with this. All else being equal, a chain turning a smaller radius increases friction.

mateo
mateo
5 years ago
Reply to  Aaron

The SRAM claim is that the small cogs also end up creating slightly higher tension on the chain, which has a positive impact on efficiency.

mudrock
mudrock
5 years ago
Reply to  Dinger

I would expect some trolling from Shimano fans, but from the the 10t cog, Sram can:
1. use smaller chainrings, which
2. allow smaller cassettes, which
3. allow tighter gear steps
4. reduce weight

JeromeB
JeromeB
5 years ago
Reply to  mudrock

Actually, using a 10t cog INCREASE the gear step. The difference between 10 and 11 is actually larger than the difference between 11 and 12.
An 11-32 (with a 52-36) would have a range similar to the 10-28 (with 48-35) with more consistent gear step.
Also, using larger gear is more efficient since the chain as to bend less.

jasonmiles31
5 years ago
Reply to  mudrock

Tighter gear steps is bogus. The difference in gear ratio between 10/11 and 11/12 is around 1% bigger.

Smaller CRs may increase chain tension reducing some of the efficiency losses from the cassette. But it will also reduce CR transmission efficiency and increase chain, chainring and cassette wear.

Dinger
Dinger
5 years ago
Reply to  mudrock

Smaller cogs don’t make smaller gear steps, they make larger gear steps, because 1 tooth is a percentage of the circle it’s a part of. By percentage, the difference between a 12 and a 13T cog is greater than the difference between a 13 & 14, 15 & 16, etc.

I’m still interested in seeing proof that a smaller chain sprocket can be as or more efficient than a larger one, with the same chain pitch, not even considering that the chain line can be compromised, depending on which chainring/cogset is chosen.

Bob
Bob
5 years ago
Reply to  mudrock

i thought a bigger chain ring gave more leverage as the chain is farther from the axle around which it is turning. this is why TT bikes go to a 58T chainring and then just run farther up the cassette. dont larger diameter cogs also give a mechanical advantage to accelerate a wheel? like the opposite of a larger brake rotor?

Sounds like the trek “engineers” started talking to the SRAM guys. “Just make it technical and they will be too stupid to know any better but we will still sell a crap load of them.”

Ve Mandaric
5 years ago
Reply to  Bob

Bob, Crank/Chainring is double side lever.
On one side is crank, the other is CR radius.
If crank is 170 and CR radius is 68 (for 34T) it is 2.5 ratio. When you have big chain ring like 54 ratio is 1.5.
What that means it is much easier to turn 2.5 than 1.5.
One can move more load with 2.5. If gear ratio stays the same let say 5:1 (55-11 or 50-10) it is easier to move %0-10 as ratio is bigger. That’s huge advantage of 10T. BTW for your info, Shimano made two patent pendings last November for new cassette body and cassette, both XTR and DA, both start with 9T
That ratio is also chain breaker. What is not good. As ratio is bigger it is putting more and more tensile force on the chain, what cause failure. That is with present chains. KMC started using higher grade alloys and heat treating of plates (beside bushings, but that cost money.

JBikes
JBikes
5 years ago
Reply to  Ve Mandaric

What? Maybe I’m missing something, but I am not sure I agree or even follow anything you wrote.

Gear ratios provide just that, a gear ratio, which is simply a torque multiplier (technically a reducer for any common road gears). The “higher” the gear ratio (CR to Cassette tooth count), the harder it is to pedal for a given desired wheel torque. Humans have a tight power to cadence relationship, hence our like of many gear ratios.

FWIW – One can’t tell the difference between a 45:9 vs 50:10 vs 55:11, except the latter will have reduced chain friction losses. Humans don’t accelerate their legs fast enough to have rotational inertia effects from their chainrings and cassettes.

rob
rob
5 years ago
Reply to  mudrook

just a guess, but shimano has a new freehub body for their XTR 10-51 12sp cassette, that if i just had to guess (or hope), they will use.

briannystrom
briannystrom
5 years ago

There are some interesting innovations here, but the glaring mistakes/shortcomings make it much less attractive.

Why in the world did they go even higher on the high-end gearing, when “standard” gearing options are already way too high for most riders? If they offered cassettes that started with an 11-tooth cog, I might be interested, but the 10-tooth cog basically makes the 12th gear useless.

Having to replace the power meter when you replace the chainrings is just insane. If they’re going to do that, they should have an exchange program where you send in your chainring/power meter combo and they replace the rings for a reasonable price. Even 50% off is going to extremely expensive.

Pete
Pete
5 years ago
Reply to  briannystrom

Yeah, having to replace the entire powermeter just to replace the rings is a HUGE mistake. They claim that the last longer and you may get 3 years out of them but with all of the alternatives on the market why would anyone go for this?

rob
rob
5 years ago
Reply to  Pete

if you recycle your powermeter thru sram, it’s 50% off. making the chainrings basicall inline with a set of dura ace rings… people already pay astronomical prices (compared to years past) on chainrings, so not too much changes here, except that you get a fresh PM with it…

mudrock
mudrock
5 years ago
Reply to  briannystrom

Regarding gear range, go with the 48-35 or 46-33 crank if the top end is too high for you. The 10t makes all this weight savings possible.

There are so many power meters out there, don’t have to be stuck with the Quarq.

mateo
mateo
5 years ago
Reply to  mudrock

This. Gear range is a bigger equation that just cassette sizes. The available ratios are barely higher than the current 53×11.

briannystrom
briannystrom
5 years ago
Reply to  mudrock

A 46×10 is still much bigger than I need; it’s a 124″ gear! Heck, when I was racing I never used anything bigger than 110″. A 46×11 would at least be usable on occasion.

Regardless of what SRAM claims, 10-tooth cogs wear quickly – if you actually use them – and they’re not smooth to pedal. It’s shortsighted of them to force this nonsense on customers when the industry trend is toward providing gearing that’s more friendly to the non-racing masses.

Jörg Hippo Thomsen
Jörg Hippo Thomsen
5 years ago
Reply to  briannystrom

I couldn’t agree more. The 10t is bonkers. WHO will be able to spin even a 46/10 at 90-100 RPM? Just forget about 50/10 or 48/10… especially with the bigger tires everybody is riding these days. Of course, for a thriathlete who will not exceed 75 RPM these gears may be sound, but for everybody else it is a pseudo scientific hype driven by the arketing department.
I love SRAM Red, but I do hope these “novel” gear combos are not here to stay.

Mark
Mark
5 years ago
Reply to  mudrock

Hopefully the apps will allow you to enter different gear ranges in the future. There are a lot of other companies making cranksets and chainrings, which it’d be a shame to be limited by the three gear sizes.

Third party cassettes might not be too common, but not completely out of the realm of possibility, and there are some manufactures making extra-large cogs to add onto a cassette.

JBikes
JBikes
5 years ago
Reply to  mudrock

I once stalled and started rolling backwards down a hill due to the weight of my 12-29 cassettes and well endowed chainring sizes.

rob
rob
5 years ago
Reply to  JBikes

lol. +1

Larry Kaatz
Larry Kaatz
5 years ago
Reply to  briannystrom

I son’t see a problem with power integrated into the chainrings.
I’m surprised BikeRumor said the chainrings would last three or more years. I’ve had old-school chainrings (not as sophisticated design as modern ones) that lasted five years or more. The (not) secret is to replace your chain often. Probably every 1500-5000 miles, depending on riding conditions and how often you clean the chain. The chain is the least expensive component of a bike’s transmission – replace it before it’s fully worn.

Marc L
Marc L
5 years ago

So Red AXS shifter, Eagle AXS derailleur, Eagle chain, and Eagle cassette for 1x groad? I didn’t see it explicitly stated but it was sort of implied above.

briannystrom
briannystrom
5 years ago
Reply to  Marc L

They actually show a “monstercross” bike with this setup in one of the other articles.

AJ
AJ
5 years ago
Reply to  briannystrom

monstercross is a thing.

Alex
Alex
5 years ago

This article definitely buried the lede: Force eTap!

Zach Overholt
Admin
4 years ago
Reply to  Alex

This story was from Feb, 2019. SRAM Force eTap AXS wasn’t released until Apr, 2019.

Brian
Brian
5 years ago

CycleOps already has an XD/XDR driver for their Hammer and H2 trainers. https://www.cycleops.com/product/hammer-xd-driver

Hank
Hank
5 years ago

Did they change the battery or can I use the batteries from my original eTap group?

Mark
Mark
5 years ago
Reply to  Hank

Other sites say it’s the same battery.

Joe Spam (@JoeSpam1)
5 years ago

Holy smokes, chainrings integrated with power meter is a horrible horrible design and an obvious cash grab.

Not to mention they kept arguably the worst hood design ever

ackertinc
ackertinc
5 years ago

They put the power meter in the chainrings??!?!? Why?!

Chris Trunek
Chris Trunek
5 years ago

lot of innovations here
, very impressed SRAM. haters gonna hate but bravo for bringing the hot new new. Cables will always be there for traditionalist

briannystrom
briannystrom
5 years ago

I just received a Jenson ad with the pricing on the road groups; it’s two grand for the rim brake 2x and hydro 1x, and $2500 for the hydro 2x. You also need an XDR driver for your rear wheel. These prices don’t include the power meter.

Dolan Halbrook
Dolan Halbrook
5 years ago

Some really interesting gear combinations could be done with this… great news for those looking for a wider gear range using road components. However putting the powermeter in a wear part is just waste of the highest order. And as the crank arms are carbon (AFAICT) I don’t think third party power meters are a possibility, at least not for a while. Terrible decision there.

Heffe
Heffe
5 years ago

The circular mounting mechanism for the chainrings looks exactly like the patent SRAM released for a chain alignment gizmo a short while ago. It was supposed to alter the chainring angle to line up with whichever back cog was being used. So… is it in fact in this crank but was not mentioned?

Trybo Bike Tech
Trybo Bike Tech
5 years ago

I am radically indiffrent.

Cassette wise, it’s all just numbers shuffling – there was enough range for majority of people before, now we have even more, so. Yay – more range I won’t use. Other then that – the group seems like a carefully crafted cross-dependancies which require to go all or nothing on it.

For example – its electronic for God’s sake. Why can’t I program it to run 9 speed? Or 11, for that matter. What is the reason other then silly vendor lock-in? Also – the power meter – an expensive part – being tied to a wear item? Who thought of that? A Darth Vader level evil marketing guy?

The clutch is cool tho. I admit.

Tom
Tom
5 years ago

I’m not a current power meter user so my comment may not carry any weight, but most of my friends have had multiple problems with their power meters, especially over the long term, certainly I did my PowerTap back in the day. So the fact that the PM is part of the chainring to me is not a problem – most of the PM stuff doesn’t seem to last much longer than a couple seasons anyway. And by using the system they have, they might be able to drive the cost down so that it’s not a big deal to replace. With regards to the 10T cog, color me unimpressed. That thing is definitely going to wear faster than an 11, and certainly a 12. And it’s going to be less efficient, and the gear jump is bigger. I’ll stick with standard rings & cluster.

Scott
Scott
5 years ago
Reply to  Tom

I agree a 10T will wear faster than 11T, but I’ve never worn out an 11T. I always wear out around 16T or 17T first, then just chuck the cassette. Is wearing out an 11T a thing people do IRL?

rob
rob
5 years ago
Reply to  Tom

+1 here.
i’ve used a ton of different power meters over the years, some solid, some not so solid. Powertap was less solid (there’s worse), but Quarq was probably one of the most reliable power meters that i have ever used. i have a couple with over 10,000 miles on them. that’s not to say that i havent seen a quarq go out. but i agree with you here, that it’s really cool that you’re able to just get a fresh unit when it comes time. plus the whole thing about 50% off when you recycle thru sram. i think they really nailed it here.

William Clay
William Clay
5 years ago

This came about a year too late for Aqua Blue…

Michael
Michael
5 years ago

https://www.bike24.de/p1313745.html?q=etap

just 1000 Euro more for the 12th gear, pretty pricy. I think I´ll order 2 sets tonight, or wait, I take 3. One for my winter ride….

Dan the angry man
Dan the angry man
5 years ago

I like how every time Sram brings out a new product they express how crap their last models were with percentages claiming the new stuff is 50% stronger etc… How long until this version of their life changing group gets made redundant and is no longer compatible with any of their new products? Every level of Shimano’s groupsets work flawlessly and their technologies trickle down the models each year keeping you able to buy replacement parts cheap for years to come when they create something new. Yeah they might not have the craziest innovation claims with fake non accessible public data but their stuff actually works so they don’t need to claim to recreate the wheel every 5 minutes.

Don
Don
5 years ago

My only hope is that SRAM did us all a solid, making the spacing on their 12 speed cassette, the same as Campagnolo, like they all did for 11 speed. Being able to grab any wheelset in my garage to ride on either a SRAM or Campy bike, is magic really. PLEASE tell me this is the case.

drjwbriand
drjwbriand
5 years ago

this is getting creepy! at some point all of these drivetrains will self-connect with skynet and revolt against us! where will the terminator be when we need him?????

rob
rob
5 years ago
Reply to  drjwbriand

skynet is going to strand us in the 33/33 at the top of the descent, and the 50/10 at the bottom of a climb.

William Pennino
William Pennino
5 years ago

guess people dont care about weight anymore

briannystrom
briannystrom
5 years ago

What makes you say that? Electronic shifting systems are only marginally heavier than mechanical systems and SRAM is the lightest of the electronic groups.

William Pennino
William Pennino
5 years ago
Reply to  briannystrom

didn’t realize close to a pound is considered marginal. my bad.

mateo
mateo
5 years ago

a pound? Compared to what?

Michael
Michael
5 years ago
Reply to  mateo

There is not much of a difference between RED and ETAP 11spd, never forgett about the cables

Thomas Bonamy-Cossard
Thomas Bonamy-Cossard
5 years ago

Nothing compatible with the already existing eTAP ? BS arguments only to sell more. Don’t tell me SRAM couldn’t make the wireless signal of the actual lever not compatible with the derailleur. They are laughing at people.

briannystrom
briannystrom
5 years ago

I just saw the price of replacing the chainrings/power meter combo. At 50% off, it’s still $410! This is laughable!

TheStansMonster
TheStansMonster
5 years ago

“Existing gear ranges were already enough for most riders” says everybody in this thread who doesn’t live somewhere that they are surrounded by 18-24% grades and like to actually pedal downhill sometimes.

Dinger
Dinger
5 years ago

The lowest possible gear ratio offered by this is 1:1 (33×33). Shimano offers this combination 105 and Ultegra (34×34). I don;t know if Dura Ace does yet.

Miles
Miles
5 years ago

I’d much rather see the 10-28 cassette lose the 17t cog and go 21-23-25-28 at the top. The 21-24 and 24-28 gaps listed here are the same you find on an 11 speed 10-42 cassette, which somewhat defeats the whole purposed of having a 12 speed double set up (i.e. close gear spacing).

Sure, the pro’s may spend most of their time in the middle of the cassette and really appreciate that 6.3% difference between the 16 and 17, but most of them will probably be on the 10-26 anyway.

And don’t get me started on the 5 tooth 28-33 gap on the biggest cassette.

Galen
Galen
5 years ago

“Plus, really, how often are any of us really riding in the smallest cog?”
Yeah that’s why I run a 58t chainring. With only a 50t ring as the largest option, it means I’ll be running more chain angle, all the time. This means a worn drivetrain and more friction

briannystrom
briannystrom
5 years ago
Reply to  Galen

58 tooth? Is that a typo or an attempt at a joke?

Galen
Galen
5 years ago
Reply to  briannystrom

No, I run a 58t on my road bike (Litepro 1x from Ebay, work great). Some quick math will show you that gives a perfect chainline @ 48kph/98rpm, which is perfect for me.
So yeah the ratios are there, but with a max of 50t on this system, the chain is over at an angle ALL the time to get it.

Galen
Galen
5 years ago
Reply to  Galen

Although this release is all about gravel/slow rides, SRAM has some pro teams that will need some bigger rings, we’ll see proper gears in the summer.

Galen
Galen
5 years ago

Are these derailleurs compatible with campy 12spd? I liked how 11spd campy/sram/shimano was interchangeable.

Heffe
Heffe
5 years ago
Reply to  Galen

This is the burning question without an answer on the internet. All it takes, I would guess, is for some kind-hearted Bikerumor editor to get out some digital calipers on a Campy 12 drivetrain and be the FIRST on the internet to solve this burning mystery. C’mon fellas, throw us a bone! Cog pitch, cog width and spacer width – let’s do this!

Heffe
Heffe
5 years ago
Reply to  Heffe

OK I found that the Campy 12 spacers are 2mm, whereas the 11 speed spacers are 2.2mm. Now all we need is a cog width measurement. I know that they are thinner. I believe that SRAM 12 speed cog pitch is 3.65 mm total.

Mic
Mic
5 years ago

(deleted)

slowslowman
slowslowman
5 years ago

Track cycling and BMX applications told us bigger ring+cog is more efficient than smaller ring+cog.
For 4X gear ratio, 56x14T better than 52x13T, 48x12T.
Nobody will use 11T Cog in track racing.

Friction facts quantify the difference between ring sizes by lab tests in 2015.

With AXS gear ratio, 2Watts will be expected to lose. Not to mention faster chain wear out speed.

Sram is brave, clever and willing to take risk. They are confident in their marketing team.

Velo Kitty
Velo Kitty
4 years ago

If you search on youtube for “SRAM AXS sucks”, there are several videos on the topic.

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