Triban GRVL 120 Anti-Chain Drop Guide

Triban GRVL 120 Anti-Chain Drop Guide

Straight from day one my wife's Triban GRVL 120 kept dropping the chain between the chainring and the original plastic guard.

I checked the derailleur, adjusted the limits, experimented with the B-tension, and even bought a replacement narrow-wide crank. None of that solved the problem.

Instead of replacing more parts, I looked at why the chain was able to escape in the first place.

The original chain guard leaves enough clearance for the chain to fall between the chainring and the guard under certain conditions. This replacement guide reduces that gap just enough to prevent the chain from escaping while maintaining safe clearance.

After installing this guide, the bike has completed over 1,000 km without a single chain drop.

Installation

1. Remove the five screws holding the original chain guard.

2. Install the new guide using the original screws.

3. Check that the guide does not rub the chain in any gear.

Installation takes only a few minutes.

Compatibility

Designed for:

• Decathlon Triban GRVL 120

• Original crankset with factory plastic chain guard

It may fit other cranksets with the same mounting pattern, but this has not been tested.

Printing

Material:

• PETG recommended

• PLA should also work

Layer height:

• 0.20 mm

Infill:

• 20%+

Supports:

• None

Disclaimer

This part was designed for my wife's bike and has been tested for more than 1,000 km. I cannot guarantee compatibility with every production revision of the GRVL 120, so please verify the clearance after installation.