Chain guide and slider

The chain slider is a plastic or rubber strip on the swingarm near the pivot, where the chain would otherwise rub on metal. Some bikes also have a chain guide near the rear sprocket and a chain guard or full chain case on top.

What it does

When the suspension moves, the chain touches the swingarm. The slider is a cheap wear part that takes this rubbing instead of the swingarm. The guide keeps the chain lined up with the rear sprocket, and the guard keeps clothes, fingers and dirt away. A loose chain wears through the slider fast.

Signs it is worn or failing

• Chain rubbing sound or marks on the guard or swingarm: Chain rubs.
• Slapping noise: Chain noise. Check the slack first.
• A worn or missing guide can let the chain come off: Chain jumps.
• Slider worn through so metal shows, or cracked guard rattling.

When to replace it

Replace the slider when worn to the metal or deeply grooved. Replace a cracked or broken guard. Fix the cause too: too much slack, worn chain or sprockets out of line.

What to match when buying

• Make, model and year; check the swingarm shape and fixing points.
• Sliders are usually model-specific. Universal ones rarely fit well.
• Guards and chain cases must clear the chain at full suspension travel.

Fitting notes

• Some sliders can only be changed with the swingarm out; see Check the swingarm pivot.
• Set slack correctly afterwards: Check and adjust chain slack.
• See Check chain guides, sliders and guards.
• When the chain is off, look at the guides on the swingarm and the slack rollers at the adjuster. Replace any that are worn.

Reference (K-Light 125)