The Rock Bottom Chain Guide is designed for most modern mountain bike frames with a single chainring. If running the Rock Bottom with this guide properly adjusted, the only way to drop the chain is to back pedal with the chain off the bottom of the chainring, suck up debris, or have chain failure that won’t allow chainring seating.
The guide is adjustable radially in the vertical direction for 38t chain rings and fewer. The guide arm mount is vertical to capture the chain at the tangent point of the chainring.
The chain guide features our Slap Guide technology. The harder your chain whips, the more it is pushed back toward the center of the chainring. We engineered the chain path to tight clearances which leaves no room for the chain to disengage from the chainring.
It comes with a set of spacers ranging from 0.25mm to 5mm that lock to the guide like building blocks so you don’t have to fumble with shims while achieving precise chain alignment. With these spacers the guide can accept a wide arrange of chain lines and still be dialed in to avoid chain rub.
The chain guide features flexible wings that absorb chain energy to dampen chain motion on rough trails.
The front of the guide is stiff to keep the chain locked dead center on the chainring.
The rear of the guide is bolted so that should the chain somehow come off it is positively captured. Often you can pedal forward and the chain will self-install depending on your chainring. If that doesn’t work you can also pedal with your hand and push on the guide to engage the chain without having to get dirty lube on your hands.
Includes all mounting hardware.