Wolf Tooth 120 BCD Chainrings

Wolf Tooth 120 BCD Chainrings Info

Wolf Tooth 120 BCD Chainrings are engineered to modernize SRAM-era 2x10 cranksets with a clean, reliable 1x conversion. Originally introduced with SRAM XX and similar 120 BCD cranksets, this bolt pattern remains a strong platform for riders who want to simplify their drivetrain without replacing the entire crank. With Wolf Tooth’s patented wide/narrow tooth design, these chainrings bring modern chain retention and durability to a proven interface.

At the core of this 120 BCD chainring is Drop-Stop® technology, Wolf Tooth’s refined wide/narrow tooth profile. The wide tooth face maximizes contact on the drive side to better distribute pedaling loads and extend chainring life. The narrow tooth clears mud and debris efficiently, reducing friction in demanding trail conditions. The alternating pattern significantly reduces the risk of chain derailment, making it an ideal solution for aggressive XC and trail riding.

These chainrings fit any compatible 120 BCD crankset or 4-bolt spider, including SRAM XX models. The smallest compatible size is 36T due to the bolt circle diameter. Riders should note that installation requires M10 x 0.75 bolts with a shoulder—these are specific hardware pieces supplied by SRAM, as standard chainring bolts will not work. Only about three threads will engage, consistent with the original SRAM configuration.

Chainline is optimized for real-world clearance and drivetrain alignment: the 36T ring runs at approximately 51mm chainline, while the 38T sits slightly wider at 52mm for increased chainstay clearance. For riders using a 9-speed drivetrain, Wolf Tooth recommends pairing the ring with a 10-speed chain to achieve tighter engagement and improved chain retention.

Wolf Tooth 120 BCD Chainrings Specs at a Glance

• Compatibility: 120 BCD cranksets and compatible 4-bolt spiders (not compatible with FSA 4-bolt cranksets).
• Tooth Profile: Drop-Stop® wide/narrow for enhanced chain retention and mud clearance.
• Minimum Size: 36T (smallest compatible tooth count).
• Chainline: 51mm (36T) | 52mm (38T).
• Required Hardware: M10 x 0.75 shoulder bolts (SRAM-specific).
• Weights: 36T – 54g | 38T – 59g.
• Material: CNC-machined 7075-T6 aluminum.
• Origin: Made in the USA.

Design Benefits

1. Clean 1x Conversion: Updates SRAM 120 BCD cranksets for simplified drivetrain performance.
2. Proven Chain Security: Wide/narrow tooth shaping reduces chain drops under load.
3. Optimized Clearance: Chainline options balance drivetrain alignment and chainstay spacing.
4. Lightweight Strength: 7075-T6 aluminum construction delivers durability with minimal weight.

Final Take

The Wolf Tooth 120 BCD Chainrings are a practical, performance-focused solution for riders upgrading older SRAM 120 BCD cranksets to 1x. With precise machining, Drop-Stop® retention technology, and Made in USA quality, this chainring brings modern drivetrain confidence to a classic bolt pattern.