The SRAM DUB [paid link] bottom bracket and crank system represents a streamlined approach to bottom bracket standards. It’s designed for durability, improved bearing longevity, and simplified compatibility across multiple frame standards. Despite its robustness, improper installation or setup errors can drastically reduce its effectiveness and lead to costly damage. This article explores the most common and expensive mistakes made with SRAM DUB [paid link] systems—and, more importantly, how to prevent them.
Misunderstanding DUB’s Compatibility Requirements
A prevalent and expensive mistake is assuming the DUB [paid link] system fits universally across all bottom bracket shells without checking specific requirements.
SRAM DUB supports multiple shell standards (BSA, PF30 [paid link], BB30, BBRight, BB386EVO), but each frame type requires a corresponding DUB bottom bracket variant. Installing the wrong version—especially in tight-tolerance shells like BB30—can lead to misalignment, creaking, and premature wear on crank spindle interfaces and bearings.
Always cross-reference the frame shell specifications with SRAM’s DUB compatibility chart before purchasing or installing. Do not attempt to “make it fit” using extra spacers or non-standard hardware, as doing so can void warranties and cause irreversible frame damage.
Incorrect Bearing Preload Adjustment
SRAM DUB cranks rely on a plastic preload adjuster ring to dial in bearing tension. Improper preload—either too tight or too loose—is one of the leading causes of performance degradation and crank spindle wear.
Over-tightening compresses the bearings, increasing drag and reducing lifespan. Conversely, under-tightening allows for side-to-side play, resulting in shifting issues and uneven wear on the chainring and bottom bracket bearings. This condition can often go unnoticed until it causes long-term damage.
To avoid this, always follow SRAM’s torque recommendations and adjust the preload ring by hand until the crank spins freely without side-to-side movement. Periodically check this adjustment, especially after a few rides or during routine maintenance.
Using Incorrect Bottom Bracket Tools
SRAM DUB bottom brackets require specific tools for installation, and using the wrong tool or improvising with pliers or generic socket wrenches can deform or damage the delicate plastic bearing cups.
Press-fit DUB bottom brackets, such as DUB PressFit (PF92, PF30 [paid link]), should be installed with a proper bearing press [paid link] to avoid misalignment. Threaded versions like DUB BSA need a compatible 12-notch tool to ensure even torque during installation.
Improper installation can cause ovalized cups or bearing misalignment, leading to creaks and irreversible damage to both the bottom bracket and the frame.
Neglecting to Grease Critical Interfaces
Another frequent and costly mistake is skipping lubrication during installation. Despite its apparent simplicity, the SRAM DUB system has multiple interfaces that require precise greasing to prevent corrosion and facilitate removal.
Commonly neglected zones include:
- Inside of the bottom bracket cups
- The spindle surface where it contacts bearings
- The crank bolt threads and washer
Dry assembly promotes creaking, galvanic corrosion between dissimilar metals, and even cold welding of aluminum components. Always use a high-quality, waterproof grease recommended for aluminum and carbon interfaces.
Skipping Bottom Bracket Shell Preparation
Installing a DUB bottom bracket into a dirty, rough, or misaligned shell can instantly compromise its lifespan and performance.
Threads should be chased and cleaned for BSA shells, while press-fit shells must be:
- Free of debris
- Face-machined (if required) to ensure parallel bearing cups
- Free from surface oxidation or carbon residue
Skipping this step can cause premature bearing failure, noise, and uneven torque during crank rotation. Always inspect and prep the shell before pressing or threading in the DUB bottom bracket.
Failure to Recheck Torque and Wear After Break-In
Even a well-installed SRAM DUB setup needs post-installation checks. Torque can settle as materials compress or temperature shifts affect metal tolerances. Cranks may loosen subtly, or preload settings may shift during initial rides.
Failing to recheck torque on crank bolts and the preload adjuster after 100–200km (or 2–3 rides) can allow minor movement that worsens over time. This can lead to stripped splines, spindle wear, or even catastrophic crank arm failure under load.
Incorporate post-installation inspection as part of your maintenance schedule to prevent future issues.
Improper Crank Removal Procedures
When removing SRAM DUB cranks, forcing the crank off without fully loosening the crank bolt or using pry tools can warp the spindle interface or damage the bottom bracket.
DUB cranks use an expanding spline interface that requires full disengagement of the self-extracting crank bolt before removal. Skipping this process can permanently deform the interface, requiring a full crankset replacement.
Follow SRAM’s official removal steps precisely. Never use a crank puller or hammer for extraction.
Installing Chainring Bolts Without Torque Spec Awareness
If using a direct-mount SRAM DUB crank with a replaceable chainring (such as the X-SYNC 2 chainrings), it’s essential to torque the chainring bolts properly. Under-torquing can lead to chainring wobble and inconsistent shifting, while over-torquing can strip the threads or damage the spider.
Use a torque wrench [paid link] and adhere to the specified 8–10 Nm range, depending on the chainring model.
Conclusion
SRAM DUB offers a simplified, cross-compatible crank and bottom bracket system, but only when installed and maintained properly. These mistakes—ranging from preload errors to improper shell preparation—can significantly reduce performance, lead to expensive component replacement, or even damage the frame itself.
By understanding these common pitfalls and following precise installation and maintenance protocols, you can keep your SRAM DUB drivetrain running smoothly and reliably for years.