When every gear shift needs to hit the mark on fast road bike sections, choosing the right chainring combination is essential. The ROTOR Round Ring 42-tooth inner chainring is designed for sporty 2x road drivetrains with a 110x4 mm BCD and can be paired with compatible 54T or 55T outer chainrings.

The round tooth profile maintains a constant gear ratio throughout the entire crank rotation. Made from CNC-machined 7075-T6 aluminum, this inner chainring provides a precise foundation for your road bike drivetrain. For installation, the specific four-arm bolt pattern and compatible chainring combination are just as important as the bolt circle diameter.

Key features at a glance:

• 42 teeth for 2x drivetrains: For compatible 54/42 and 55/42 road gearing.
• Round chainring profile: Constant gear ratio throughout the entire pedal stroke.
• 7075-T6 aluminum: CNC-machined design for sporty road drivetrains.
• 110x4 mm BCD: For compatible four-arm crank spiders with the matching bolt pattern.

Technical specifications:

• Manufacturer: ROTOR
• Model: Round Rings
• Product type: Inner chainring
• Intended use: Road cycling / road
• Number of teeth: 42 teeth (42T)
• Position: Inner
• Drivetrain: 2x
• Speeds: 2x10-speed / 2x11-speed
• Compatible chainring combinations: 54/42 and 55/42 teeth
• Bolt circle: 110 mm BCD, 4-arm (110x4)
• Chainring profile: Round
• Material: 7075-T6 aluminum
• Manufacturing: CNC-machined
• Color: Black

Compatible with:

• ROTOR crank spiders with a matching 110x4 mm BCD bolt pattern
• Compatible ROTOR INspider mounts with 110x4 mm BCD
• Compatible 2x10- and 2x11-speed road drivetrains
• Compatible 54T or 55T outer chainrings for 54/42 or 55/42 combinations

Included:

• 1 x ROTOR Round Ring 42T inner chainring, Black
• Packaging: Original packaging

Manufacturer part no.: C01-516-19010-0 | EAN: 8434366016030

The round ROTOR inner chainring adds a compatible 42T gear ratio to your sporty 2x road drivetrain.