Sram DUB
If you've spent any time in the bike community, you've probably encountered SRAM's new DUB system. As if the cycling world needed another standard to keep up with...
Regardless, we're here to demystify this new system and help you understand what it means in terms of what gear will and won't work for your bike.
What the heck is DUB anyway?
SRAM's DUB (Durable Unified Bottom Bracket) is a bottom bracket system designed for use with SRAM's cranksets. The DUB system aims to simplify bottom bracket compatibility by offering a standardized design across various frame types and bottom bracket shell widths. So says the official technical page on SRAM's website.
But why create a new "standard"? This is probably what most people, including our service techs, are asking. Here are some of the reasons that SRAM themselves have given:
Key features of SRAM DUB include:
Compatibility: DUB is designed to be compatible with a wide range of bottom bracket standards, making it easier for cyclists to choose the appropriate bottom bracket for their frame.
Crankset Compatibility: SRAM DUB bottom brackets are designed to work seamlessly with SRAM's DUB cranksets, ensuring optimal performance and durability.
Unified Spindle Diameter: DUB standardizes the spindle diameter across various bottom bracket standards, simplifying the choice of components and reducing compatibility issues.
Increased Durability: The DUB system is engineered to provide increased durability and reliability, offering cyclists a robust solution for their bottom bracket needs.
Improved Seal Design: SRAM has also focused on enhancing the sealing system to prevent contaminants from entering the bottom bracket, contributing to improved longevity and performance.
Ok, SRAM. But what does this actually mean? Let's get down to the nitty-gritty information that you really need to know.
Nuts and bolts
Basically, what this boils down to is that you can't use a SRAM DUB-designated crankset with any bottom bracket other than a SRAM DUB.
The DUB crankset spindles measure 28.9mm with the usual mechanizing variations. SRAM is listing this as a 29mm spindle in technical documents. Most crank spindles on the market now come in two flavors: 24mm and 30mm.
So let's say you want to upgrade the stock cranks that come on your bike. You pick out a sweet new SRAM Eagle 1x system to replace your current Shimano HollowTech system. Even though when you take the cranks out, the spindle of the Shimano crank and the new SRAM crank look like they would be interchangeable, they aren't. The Shimano spindle is 24mm, which won't accept a 29mm replacement. You can still use the SRAM crank, but you're going to need a DUB bottom bracket that fits your frame as well.
The bottom line here is that if you are considering purchasing a SRAM crankset, be sure to check the technical documentation for the correct bottom bracket.
Fortunately, Sram is making a wide variety of bottom bracket styles (why wouldn't they?). So even if your frame takes a BSA threaded, PF30, PF92, etc., they have a bottom bracket that they would be happy to sell you for your new cranks.
We hope this clears up some of the questions that we've been getting about the new DUB system. As always, if you have questions about what will and won't fit your bike, stop by the shop or send us a message!
NOW GO RIDE YOUR BIKE!