SRAM S150 Eagle Transmission B1 12-Speed 32T Powerspline Boost Crankset

The SRAM S150 Eagle Transmission crankset brings Eagle Transmission (T-Type) compatibility to riders at an accessible level, with robust aluminum arms and a sturdy 32T steel T-Type chainring. SRAM offers it in progressively shorter lengths, with a black finish that pairs with Eagle 70.

This listing covers the full range: 155, 160, 165, 170 and 175mm. Every version uses a Powerspline spindle in a 118/73 Powerspline bottom bracket (sold separately), a 52mm chainline and Boost drivetrain spacing.

Who It's For

• Mountain riders building or upgrading to SRAM Eagle Transmission
• Boost-spaced bikes running a 52mm chainline
• Smaller riders and kids' builds that benefit from 155 or 160mm arms
• Consider a different crank if your frame needs a DUB bottom bracket

What to Look For

• Spindle interface: Powerspline; requires a 118/73 Powerspline bottom bracket, not included.
• Chainline and spacing: 52mm chainline, Boost.
• Crank length: 155 to 175mm in 5mm steps.

Key Features

Steel T-Type ring. The 32T 3-bolt direct mount ring is steel and built for Eagle Transmission, so it is made for the T-Type chain rather than earlier Eagle chains.

Aluminum arms. Robust aluminum arms keep the crank durable and accessible, and the black finish is chosen to match Eagle 70 components.

Powerspline spindle. The spindle runs in a 118/73 Powerspline bottom bracket, which is sold separately. Confirm your frame accepts it before ordering.

Shorter length options. The range reaches down to 155mm, which opens Eagle Transmission to riders who need shorter cranks.

Rider Intent Summary

• Biggest strengths: Eagle Transmission compatibility with a durable steel ring and lengths down to 155mm.
• Tradeoffs: Powerspline bottom bracket required and sold separately; steel ring is heavier than aluminum.
• What makes it different: Five lengths on one listing, from 155 to 175mm.

Victory's Take

At Victory Bicycle Studio we use this listing to compare lengths side by side, then confirm your bottom bracket is a 118/73 Powerspline before anything ships. Ask us if you are between sizes.

Specifications

• Speeds: 12 (Eagle Transmission)
• Chainrings: Single
• Ring: 32T steel Eagle T-Type
• Chainring mount: SRAM 3-bolt direct mount
• Spindle interface: Powerspline
• Bottom bracket required: 118/73 Powerspline (not included)
• Chainline: 52mm
• Drivetrain spacing: Boost
• Crank lengths: 155, 160, 165, 170, 175mm
• Material: Aluminum arms
• Pedal thread: 9/16"
• Color: Black
• SRAM model ID: FC-S150-B1
• Bottom bracket: Not included