SRAM's New DUB Cranks and Bottom Brackets - First Look
What's DUB?
SRAM have announced a major revision to their mountain bike cranks and bottom brackets, a change that's intended to increase bottom bracket longevity, as well as simplify the lineup. The revamp also allowed them to shed a significant amount of weight from the XX1 crankset, and it's now claimed to be one of the lightest options on the market.
Called DUB (Durable Unified Bottom bracket), the most significant update is the change to a 28.99mm spindle for all mountain bike cranks. Previously, SRAM had two different spindle diameters (30mm and 24mm), along with a range of bottom bracket bearing sizes. With DUB, they now offer one spindle diameter and four bottom brackets that will fit all of the existing frame standards.
Where did that 28.99mm number come from? Why not just switch everything over to 30mm spindles and call it good? According to SRAM, their product development in San Luis Obispo, California, tried multiple configurations, beginning with the existing 30mm spindle size, before settling on what they felt offered up the ideal balance of bearing size, durability, and weight. The new bottom brackets have more seals than the previous models in order to keep contaminants like water and dirt from working their way into the bearings. Along with the improved weather sealing, SRAM has gone to metal cups on their press-fit bottom brackets, rather than the plastic cups used previously.
The following video from SRAM provides a little more insight into the concept, as well as a chance to witness some interesting Movember facial hair:
The X-Sync 2 SL chainrings found on the XX1 cranks are designed to be as light as possible.
All of the cranks now have 28.99mm spindles, and use a threaded bearing preload ring.
XX1 Gets Lighter
All of the cranksets in the lineup have been updated with the new spindle size, but it's the XC-oriented XX1 crankset that received the most significant makeover, one that allowed SRAM to shave 80 grams off the total weight compared to the previous version. Claimed weight for the cranks with a 32-tooth direct mount ring is 422 gram. The weight savings comes from the use of a lighter spindle, as well as a lighter chainring design, where any unnecessary material has been machined off. Not that the performance of professional athletes should be used to justify a purchase, but for what it's worth, Nino Schurter won the World Cup XC overall and World Champs aboard a DUB-equipped bike.
The chamfer at the end of the spindle is intended to help prevent it from catching on the bottom bracket's seals during installation.
It's too early comment on the effectiveness of the new seal design, but once we get a crankset in for review it'll see plenty of muddy miles.
There are now four bottom bracket options to fit the variety of frame designs on the market.
Can I Still Get GXP Bottom Brackets?
The DUB cranks and bottom brackets do replace SRAM's previous models, but there's no need to rush out to start hoarding all the bottom brackets you can get your hands on – replacement parts will be available for at least the next three years, if not longer. Keep in mind that it's been eight years since SRAM last updated their bottom brackets – it's not a component that constantly changes. That being said, the update does mean that shops will need to stock bottom brackets that work for SRAM cranks with 24, 30, and 28.99mm spindles, at least for the near future. Good thing bottom brackets don't take up as much space as wheels...
SRAM's DUB technology will be found on everything from the highest end XX1 carbon cranks to the more affordable aluminum Truvativ Stylo cranks. DH options haven't been announced yet, but they're in the works.
Specifications and Pricing
• XX1 Eagle: $515 - $525 | €570 - €585 | £510 - £520
• X01 Eagle: $485 - $495 | €540 - €550 | £480 - £490
• GX Eagle: $135 - $185 | €150 - €205 | £135 - £185
• Descendant Carbon DUB: $260 | €290 | £255
• Descendant 6K DUB: $105 | €115 | £105
• Stylo Carbon: $260 - $310 | €290 - €345 | £255 - £305
• Truvativ Stylo 6k: $105 | €115 | £105
• Bottom brackets: $38 - $50 | €38 - €52 | £32 - £44
MENTIONS: @SramMedia
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ahahahaa
I'm a fan of Sram's stuff don't get me wrong but...the last 3 standard changes they committed to are a real bummer. Boost only front forks for 2018, metric shock standard (I hate this one the most), and now this. I guess this one is minor because it is only a BB but...for now it blocks customers from upgrading BB's to a King or Wheels MFG or someting of the like. I guess that's the point though.
edited beacuse Maths
What about the chainring, have they changed the mounting spline / interface or is at least that still the same?
Bloody stupid comment. If you read the article instead of whincing, you would habe noticed that those spindles are compatible with both bsa and pf bottom brackets, which is exactly the opposite of what you claim: This new system IS COMPLETELY cross compatible with the most common bb standards. From now on, you can use the same crankset for both, BSA and PF.
The chainrings are the same, so you can use every Sram chainring.
They needed to put out a new product on the market (new products more sales) and they figured if they go to 30mm there are several other brands BB and axels to choose from (rf, cannondale, etc etc.). They went with an odd number to increase their sales.
www.youtube.com/watch?v=aj0_if5Fozg
"But it's not compatible with existing SRAM and aftermarket 30mm, 24mm or 24-22mm stepped bbs that pretty much every crankset on the market currently fits. It's a calculated move by SRAM to freeze out third parties from bottom bracket sales, if only for a few months while they go into their CAD files and make the inner races 1.01mm smaller."
GROUNDBREAKING!!!
Oh, and the shops now have yet another item to stock.
Shops hate selling things. Its the worst for them.
I currently keep 7 bikes rolling, all of them having compatible cranks, and BCD's matter to me. BB compatibility is not so bad, it's finally more frame related (of Vs threaded).
New bike with DUmB? f*ck.
29 mm instead of 30? Come on...
I suppose they made it so that they can squeeze this thicker axle into to the smaller diameter BB shells (41mm press fit and BSA)... where 30mm just didn't fit.
www.pinkbike.com/news/avid-elixir-interbike-2008.html lol
Have this and want it? Great, enjoy your new bike and ride on.
Have this but don't want it? Great, swap to one of the million existing BB/crank combinations and ride on.
Don't have this but want it? Great, pick one up for whatever BB standard your frame has and ride on.
Don't have this and don't want it? Great, post a bunch of scathing comments on PB and ride on.
Kinda like Boost using 148mm instead of 150mm so that things like chainline don't get screwed up.
I bet you could, and it'd be a boat anchor.
Marketing: Just make sure they aren't cross compatible, we don't want people using the Cinch 30 BB for ours
SRAM Engineer: I got you, 28.99 it is.
Marketing: We'll just tell the public that it's because of engirneering improvements, afterall, SRAM | Incremental enhancements. Perpetual improvements ...
SRAM: We downsized the 30mm spindle to make a more durable bottom bracket in your press fit frame
Aslo a PinkBike Comment: Why didn't SRAM use a 30mm Spindle so I could re-use the 3 clapped-out bottom brackets I already own?!?
Someone already does. This is SRAM solving SRAM´s problems, not the industries. Nice that you applaud the multinational global efforts they are making to increase their bank balance though. Sure they appreciate it
Funny you bring up Praxis, their products are great, but their 30/28mm M30 stepped axle is just as unique as this one, without the likelihood of as much 3rd party support.
Pinkbike commenters just savage any company whose revenue eclipses a threshold, even though the folks working at them are just as committed as the smaller brands.
The article mentions how this change will hurt smaller players like race face. I don't see how. Did they get hurt when it changed from Isis to whatever the name of 24mm is? Did they get hurt when 30mm came out? They will make compatible stuff, and sell it to make money, just as they always have. Personally I don't think this bb thing warrants an article at all, much less two.
So the spindle size has shrunk by 1.01mm so the bearing has 0.55mm (just over half a mm) more space. So you can increase the radius of the bearing ball by 0.275mm (a little over quarter of a mm). And this results in gains in durability? Really? HOW MUCH!?
Same as with frame tubing.
And also like with frame tubing, the smaller diameter steel one is more flexible, something Danny may want when hucking to flat on his rigid bike.
Assumptions though, if someone can confirm...
Besides the questionable facial hair, this is a great idea. They rightly saw that 30mm was too large and had bearings too small for the benefit, so they probably just went with the next largest size standard bearing, and that worked out to a 28.99mm spindle. I'm really behind this new design since (eventually) it will lead to a standards reduction; it won't matter what your frame is when buying used cranks anymore, just get a new BB (something you don't want to buy used anyways).
For steel axles and aluminum cranks 24mm has it covered. Good riddance GXP, was always retarded just as well.
The "problem" was the BB30 crank sets could be used with 3rd party BB's since it was a standardized size.... For frames with large diameter BB shell's such as PF30 (46mm inside shell diameter) I actually preferred the BB30 axle version with a nice durable BB such as hope "PF46". Not an option anymore with these DUB's.
I'm pretending this 28.99 thing isn't happening, but I fear it's going to become a PB meme.
Could not they at least use Campy's 25mm?
But 30mm had to go. It was a wrong choice by Cannondale (? Earliest I remember at the moment.)
Seriously though, everyone forgets when BBs were 10 different widths for chainline compatibility with different square-taper offsets and 68/73mm bb dimensions. Or when aftermarket chainrings always sucked and requires washers. Or when ISIS and its variants came along. Or early Merlins and Fishers with press-in bearings and custom axles. I'll stop here. None of this whining about "standards" is remotely new.
I hate to admit it, but this is a step in the right (albeit proprietary) direction.
Its funny though, Profiles have barely changed what they have done for all the years (over 30 now) and it still works.
A Mate built up a 19mm bossless set for his daughter with a ti spindle. With the Euro BB (BMX Race Bike) and chainring it came in at something like 50grams heavier then some of the lighter choices. Basically a bombproof set up that will outlast the alloy cranks.
The whole BMX scene seems to be about how to make it simple and durable, which can be had at the expense of only minimal weight.
Still, if you want stiffness in a spindle, why not go Chromo, sacrifice a few grams (or would it be the same because you could go smaller, such as 24mm, although in my column cranks the 22mm is stupidly strong) and be able to have larger bearings. maybe even coax them back to threaded BB's and have multiple rows or bearings for load spread.
trumpgolfcount.com
#SUPERNEWS
Even "24mm" spindles from various brands aren't always compatible. IIRC, Shimano actually measures more like 23.95, where FSA is a true 24. Sounds inconsequential, but I had a 24mm FSA crank that would absolutely not work with an aftermarket "24mm" BB. A Shimano crank worked fine.
Since this doesn't impact frame compatibility at all, no reason for the uproar other than "OMG SIZE WTF GRRR!"
I still call bullshit.
Nice to hear what they think of Pressfit.
In every other way: Yes, bullshit!
I am glad the old 29,01mm did not make it and 28,99mm ist the way to go!
Never had a problem with easy to replace $25 Sram GXP BBs, and if you did, they were super easy to swap out and there were a half dozen blinged out upgrades available.
I agree tho and will call BS on the BOOST garbage. In 2013 (FIVE YEARS AGO!) Specialized released a 29er with short 430mm chainstays, 2x compatible frame without BOOST. 148 just allows designers to be lazy, and for 275+ bikes (which proved to be a dud). BOOST 110 on the front was an absolute scam from day one.
By changing two options into one, that is, by definition, a simplification.
I'm not sure how there are this many people who don't see 2 > 1 being simpler.
As an engineer? Heck if I know! I don't like that .99 dangler either, but my point wasn't arguing their numbers choices, it was pointing out the rampant hypocrisy in everyone's pissy comments.
They could have just gone 30mm, and actually simplified things. But they didn't, which proves that this is nothing more than forced obsolescence.
...And since we keep BUYING THEIR PRODUCTS, who's winning that war?
A decade ago: "26-4-LYFE I'll never change wheel sizes!!!"
Crickets now, boys.
as usual, there is an xkcd for this
xkcd.com/927
And that's the great thing about standards: there are so many to choose from!
and then we made the spindles 29.99mm hahahhahaha
"how do we sell our new standard cranks?"
"lets not call it a standard say the opposite of what it is"
"Yeah that seems to work for Trump!"
And when you rock strike for the 100th time you'll be fine since it is f*cking metal.
Also, shimano crankset mounting is 100x better than everyone else. I've never seen someone f*ck-up a shimano, I've seen literally dozens of loose SRAM/Race Face setups.
But whatever, a bunch of you jack-holes will buy these f*cking pieces of garbage and yet another standard makes it main-stream.
But both times I've been able to just pound them off with a hammer and hammer them back on with zero problems afterwards.
Knowing myself if I bought one of those $600 cranksets is I'd probably break it taking out of the box.
Rebuild about 10 things on your bike. Loosely tighten your crankset and pivot points.
Go out to garage and grab the torque wrench.
Tighten all pivots precisely to manufacturer's specifications.
Forget to tighten the crankset.
Have an awesome ride and then when you are headed back to the car, wham!
Hmm, why is my bike pedalling weird? Oh the arms aren't parallel anymore.
Grab hammer, pound off. Reinstall.
Shimano have employed an economy of scale. The BBs are cheap and reliable.
What SRAM has done is introduce a VARIENT, not a STANDARD. Proliferantion is a cancer to productive industry
SRAM offers a 2 year warranty on their bottom brackets.
Chris King offers a 5 year warranty on their bottom brackets.
My bike has SRAM, Shimano, Raceface and Chris King components.
For shops, there's literally zero problems. The usual smorgasbord of SRAM BBs will still be available, only now any bike that comes in with a "DUB" crank in need of new BB is made about 17 times easier to deal with. Bike with a DUB crank needs a new BB? It's literally one of four, only. Realistically probably only one of two BBs for most shops. Which means it'll be a lot easier to stock SRAM BBs, making easier and faster for you to go to your local shop to have yours replaced. As Charlie Sheen once said, now we're bi-winning.
Other benefits? An XO1 crank is now lighter than a Race Face NextR crank. And it's less expensive. And it's easier to deal with and there's no need to mess around with a removable spindle. An XX1 crank w/chainring is now roughly 100g lighter than an XTR 1X Boost crank before you bolt a chainring onto it. Is the 28.99mm spindle any stiffer? Doesn't matter. It's lighter, at least as stiff, durable, and plays nice with pretty much every bottom bracket shell standard that actually matters and is in common use. So now we're actually tri-winning, maybe?
The only stupid thing is SRAM deciding to make a bigger deal of this than necessary. Fact: this isn't a big deal to bike buyers and riders. The annoying video and press releases that make it seem like this is the best thing to ever happen to bike components are silly. You found a way to drastically reduce your SKUs and make life a bit easier for product people everywhere, you haven't cured cancer. Get over it.
"So right now product managers, designers, engineers, and even accountants at mountain bike manufacturers are all in agreement: this is a great development. Picking a crankset for a production bike just got a lot less tedious, as did making sure you got the right bottom bracket and that the whole thing actually works properly with a given drivetrain"
yeah, its called Shimano HT2 24mm :-D :-D
All my bikes of varying ages all have shimano cranks, or shimano compatible cranks. I simply wouldnt introduce any press fit or SRAM nonsense without fully understanding how to build it with Shimano cranks!
Shimano have always had BSA BB as the default fitting and never felt the need for oversize alloy spindles when they can make a full alloy crank with a steel spindle weigh less and be more reliable.
Glad I’m almost finished converting to Shimsno and seriously thinking about Box, MRP, TRP, etc. and any other US based MFG who values their customer instead of emptying their pocket books and extracting their passion for the sport.
Furthermore, your argument is that those companies value their customers by not doing as SRAM has (innovate better products), a point which I think all of those companies would argue against. Every company has to change standards to make better products. Even Shimano.
What do you expect from a company who charges $1500 for a drivetrain? For them to have your financial interests in mind? I get it, each new model that comes out, I itch to have it whether a frame set or component, but what stops me for the most part is stuff like this...
And GXP was a stupid "standard".
Lets keep it 24mm Shimano for steel and titanium spindles, and 29mm for aluminum ones.
That way you could use existing cranks with only one BB and when changing cranks you would not have to think about which bb to get.
But of course that means they wouldn't sell as many crank or bbs and that there would be less junk in the world.
There should be a law that forced all brands to pay millions of eco tax when changing standards after less than 10 or 20 years.
Not trying to argue, just asking questions.
I couldnt care less if its a metric trunnion boosted falcon. Just improve your shit before complicating the range of products.
Is this a new "standard"? I would argue that it's not. It's a new, incremental development that allows bicycle and component manufacturers to simplify their design, procurement, and manufacturing processes. Manufacturing isn't cheap and any opportunity to simplify how something is made by making common parts and processes is big money for a company.
Does it impact you as a consumer? Well, you can still purchase 24 mm or 30 mm BB's from SRAM for another 3 years or any other number of aftermarket manufacturers beyond that. You'll be able to run whatever BB and crank set you want for the foreseeable future. So no, it probably doesn't impact you as much as you think.
Not only that, but going forward, they will have just one "standard" so now you don't have to worry about multiple sizes and making sure you have the correct BB or spindle size. That's a win.
As far as the 28.99 thing, what does it matter that the spindle isn't a nominal size of 29.00? I guarantee that many of the nominally sized components on any bike aren't exactly that nominal dimension. From an engineering perspective we have to add clearance and tolerance to parts all the time to make things fit. It's a bit weird that something like that has ended up in sales literature, but to you as a consumer and user it doesn't actually matter.
WTF?
F this S!
Seriously, threaded outboard bearing cranks made sense, and still do for so many reasons. I'm not against change, but it should be change for a reason, not to sell more $hit. Cartridge bearing bb's? Awesome! Direct mount Chainrings? Makes sense! Narrow wide? Love it!
Change for changes sake and to sell more product? Boo Yucky!
Before someone starts in with all this stiffness crap, look at the shoes most people are riding in, if people really cared about stiffness, they'd be riding with stiffer soled shoes.
Rant over, I'm going back to my cave, wake me up when we're finally back at some type of "standard".
I wonder if a major manufacturer is about to have a mid-year release of a new model.
I actually like the change, as long as it gets away from the marginal durability and longevity bottom brackets that accommodate a 30mm spindle in a standard BB shell.
Going from 30mm spindle to 29mm (sorry 28.99mm) makes no sense. First why the .99. Just call it 29mm, makes no sense to design something to two significant digits like that. And please tell me how 1mm difference makes a difference vs 30mm? Other than forcing BB and cranks to be purchased together? I see this as a move to keep people from buying competitor cranks as an "easy" upgrade to the OEM cranks.
My bike also got BOOST so crank replacement choice is not so big also((
I hate SRAM (except Rockshox, they’re really good).
SRAM are a pain for tinkering with stuff. They were on board with Boost, gave us torque caps, 30mm crank spindles and now 28.99mm and they wonder why people think they're just a marketing company? Shimano manage fine on thinner crank axles.
30mm was for roadies. They did not give a f*ck about riding in mud, so it was doomed to failure. Getting the largest aluminum spindle that can fit in reliably does make sense.
They still will use standard 6806 bearings (like 24mm designed for 6805), but with better seals and such.
So, it's not a bad move
SRAM: "OK, we'll change the crank spindle diameter and say it's all good now. It will take people years to figure out nothing's changed"
30mm bearings by hope work with them and theyre the bomb.
The lower priced 24mm spindle cranks are brilliant foe the money also
Eat a dick SRAM.
GTFO! :]
That said, the more companies come out with new standards, the more companies like @bbinfinite will come out with products to make things better.
Dub who?
24mm axles and threaded bbs!
"When do we want it? "
April fools: 01/04
4*4=16
1*4=4
It sadly does not work, so oh well its not a joke, confirmed
www.youtube.com/watch?v=Jj0uBQ7j5c4
Stiffnes, durability? Hardtail...
חרטה.
ERROR 404: Earth curvature not found
Check ODD TV on YouTube
Pot calling kettle, yer black.
(Yes, as an engineer, I can see how that .99 is really cringe-inducing for the autists among us, but c'mon, simplifying a system gets them in hot water? How?)
"We aren't that stupid" is the moral of this story.
I'ma beg to differ that the vast majority of MTBers will ignore or boycott this...
What's your tire size? What's your current BB type? What about stem type and bar OD? C'mon fellers, when a mfgr moves to a new number / type / gizmo, we all go eventually.
Frankly, the gall is misplaced. Don't complain that they chose something new unless, Like @WAKIdesigns, you actually reference a good reason to keep one old standard or the other. Waki makes the case that 24mm should have been kept. He makes a fair point!
Yes, you're very right.
Also, in two years, at least one of the two of us will probably be riding this setup.
*SHRUG*
Just like all other standards, we don't have a choice in the matter other than just giving up the sport (because that's what "just not buying a new bike" would be). I was just pointing out that we know what this really is.
Yep. That I'll buy.
Heck, I have a perfect example. CAD, Revit, and other drafting software - much like Windows and it's miserable compatibility issues - forces companies like mine to pay for seat-count subscriptions to force updates we wouldn't normally pay for, because we just don't need them as often as the creators think we do.
We're being sold to, and you're correct, at least it's good that we recognize it.
Sram is claiming that the 30mm aluminum spindle is lighter than a 30mm steel spindle and their 24/22mm GXP spindle which is correct.
All in all, an XTR 1X setup with an aftermarket ring weighs 20-30g more than a comparable XX1 Eagle setup but is far more durable (the number of failed Sram carbon cranksets is astounding).