Summary

Super Boost Plus is a rear hub spacing standard that uses a 157 mm wide rear axle combined with wider chainline spacing to enhance wheel stiffness, drivetrain clearance, and frame design flexibility. Originally adapted from downhill bikes, Super Boost Plus is now used on some trail, enduro, and e-MTB platforms to address stiffness and tire clearance demands.

Key Facts

Introduced: 2016 (as an adapted trail/enduro standard)
Category: Concept / Technology
Also known as: Super Boost 157, Super Boost, 157TR, SB+
Hub spacing: 157 mm rear axle width
Chainline: Typically 56.5 mm or wider
Axle type: 12×157 mm thru-axle
Used by: Pivot, Devinci, Knolly, Diamondback, Orbea (on select models)
Derived from: 157 mm DH hub standard
Not compatible with: Standard Boost (148 mm) without frame-specific adapters
Official website: None (open standard promoted by Pivot and partners)

Overview

Super Boost Plus emerged in the mid-2010s as trail and enduro bikes pushed into longer travel, larger tires, and burlier builds — particularly with the growing influence of e-MTBs and long-travel 29ers. Traditional 148 mm Boost spacing, while an upgrade from the older 142 mm format, had limitations when trying to combine large wheels, short chainstays, wide tires, and high drivetrain stiffness.

Enter Super Boost Plus: a standard that re-uses the 157 mm hub width from downhill bikes, but adapts the frame, chainline, and Q-factor spacing for trail and enduro applications.

While not universally adopted, Super Boost Plus has found a home among brands that prioritize rear-end stiffness, tight back-end geometry, and the ability to run wider tires without compromising chainring clearance or derailleur alignment.

From a technical perspective, Super Boost Plus creates more spoke bracing angle — improving lateral and torsional wheel stiffness — and opens up more room for modern suspension designs. It also shifts the chainline outwards, which can improve chainstay clearance and allow for more aggressive tire/frame pairings.

But the standard has not come without controversy. Some view it as an unnecessary deviation in an already cluttered landscape of hub standards. Others see it as a future-proofed solution for the increasing demands of hard-charging modern trail bikes.

How It Works

Hub and Axle Spacing

Super Boost Plus uses the same 157 mm wide rear hub that has been used in downhill bikes for years. But instead of being limited to DH-specific frames with wide rear triangles and non-standard drivetrains, Super Boost adapts that width to work with standard trail and enduro geometries.

The 12×157 mm thru-axle hub sits 9 mm wider than standard Boost (148 mm), creating more space between hub flanges. This allows wheel builders to:

Use less dish
Increase spoke bracing angle
Improve lateral and torsional stiffness

The hub flanges are spaced approximately 78 mm apart (vs. ~68 mm in Boost), making for a significantly stronger rear wheel — especially helpful for 29” wheels and aggressive riding.

Chainline and Drivetrain

Super Boost Plus typically requires a 56.5 mm chainline — wider than Boost’s 52 mm standard. To achieve this, cranks and chainrings must be designed or spaced accordingly.

Common changes include:

Super Boost cranksets with increased Q-factor
Chainrings offset 3–5 mm further outboard
Derailleur adjustment for alignment

Despite using a DH hub, the drivetrain is still a standard 12-speed setup (SRAM Eagle, Shimano Hyperglide+, etc.) — meaning parts compatibility is possible, but not always seamless. Brands like Race Face, e*thirteen, and SRAM have introduced Super Boost-compatible cranksets and chainrings.

Frame Design Benefits

By pushing the rear triangle outwards, Super Boost opens up the space near the bottom bracket and chainstays. This allows designers to:

Use shorter chainstays, even with large 29” tires
Fit wider tires (up to 2.6”–2.8”) without chainring interference
Reinforce rear triangles with better tube alignment
Position pivots or suspension links more freely

These advantages make Super Boost especially attractive for long-travel 29ers, enduro bikes, and e-MTBs — categories that regularly push packaging constraints.

Design Goals & Controversy

Intended Benefits

Wheel stiffness: Bigger flange spacing dramatically improves spoke triangulation — especially beneficial on 29” wheels with more leverage.
Frame stiffness: Wider dropout stance enables broader pivot mounts and stronger chainstay/yoke areas.
Tire and drivetrain clearance: Widens space between chainring and tire, allowing larger rubber and shorter stays.
E-bike readiness: Makes room for motors, linkage hardware, and battery shaping near the BB area.

Common Criticisms

Compatibility confusion: Riders need Super Boost-specific cranks and chainrings — adding complexity when upgrading or building custom bikes.
Fragmentation: Yet another axle standard in a field already filled with 135, 142, 148, 150, 157, and others.
Q-factor increase: Some riders dislike the wider crank stance, especially for XC or shorter riders.
Limited wheel availability: Not all hub/wheel manufacturers support 157 mm spacing in trail-focused builds.

Despite pushback, Super Boost Plus remains in use on several high-performance bikes, where the packaging and stiffness gains outweigh the drawbacks for many riders and designers.

Notable Implementations

Pivot Firebird – Long-travel enduro bike using Super Boost for wheel stiffness and short stays
Devinci Spartan – High-speed enduro platform with 157 mm rear spacing
Knolly Chilcotin – Aggressive trail/enduro platform built with Super Boost for clearance and geometry
Orbea Wild (previous gen) – Bosch-powered e-MTB using Super Boost to house motor and 29″ wheels
Diamondback Release 29 – Affordable all-mountain bike with Super Boost for big-wheel stiffness

Related Terms

References

Pivot Cycles: Super Boost Technical Whitepaper
Race Face: Crank and Chainline Compatibility Charts
SRAM Technical Docs: Eagle Crank Fitment
Devinci and Knolly Geometry Guides
Pinkbike Tech Article: “Why Super Boost Exists”
Wheelbuilder Notes from DT Swiss and Industry Nine