77designz Oval Guide BB-38

The OVAL GUIDE - BB-38 from 77designz is a lightweight and adjustable chain guide specifically for oval chainrings, engineered to be mounted via the bottom bracket for bikes without ISCG 05 mounts. Designed with Front Flip Technology, it allows for tool-free chain access, simplifying maintenance and making it a perfect fit for trail and enduro riders.

Features

• Crank-Free Installation: Can be installed without removing the crank for a quick setup.
• Single Tool Requirement: Uses a Torx 25 for streamlined, single-tool adjustments.
• Boost Compatibility: Adjustable for chainlines from 48–53 mm.
• Front Flip Technology: Provides easy, tool-free chain access and crank removal without disassembly.
• Mud-Resistant Design: Open cage construction for better mud shedding, maintaining chain guide efficiency.

Specifications

• Mount: BSA Bottom Bracket (Threaded BB)
• Capacity: Fits 26–36T oval or 24–38T round chainrings
• Chainline: Adjustable from 48 to 53 mm (Boost Ready)
• Drivetrain Compatibility: Works with 1x10, 1x11, and 1x12 setups
• Backplate Material: AL 7075 T6, anodized black
• Slider Material: PA66 GF 10 (Front Flip Technology)
• Hardware: Includes Torx 25 hollow bolts
• Weight: 20.4 grams (including mounting hardware)

Scope of Delivery

• Chainline Spacer Set
• 77designz Sticker

Important Compatibility Notes

• Incompatibility: Not compatible with Bionicon and Garbaruk non-boost chainrings in sizes 26T, 28T, and 30T due to smaller chainline requirements.

This guide is built for performance, giving oval chainring users reliable, lightweight chain management in a highly adaptable, easy-to-maintain package.