Symptoms
- Squeaking or creaking noise from the fork over bumps
- Fork feels stiff or doesn't rebound smoothly
- Visible dirt buildup around the fork seals
- Fork sag feels different than when new
Likely causes
- CommonDirty or dry fork seals and stanchionsDirt and lack of lubrication increase friction and can cause noise and stiction.
- PossibleLow air pressure or oil level (air/oil forks)Suspension performance depends on correct air pressure or internal oil volume.
- PossibleWorn bushingsInternal bushings wear over years of use and can develop play or noise.
- PossibleLoose fork mounting bolts or headsetLooseness elsewhere on the front end can be mistaken for fork noise.
What to do
- Wipe down the stanchions (the shiny lower tubes) and seals with a clean rag before and after each ride to reduce dirt intrusion.
- Apply a suspension-specific lubricant designed for fork seals, following the product's instructions.
- Check air pressure against the manufacturer's sag chart if it's an air fork, and adjust with a shock pump.
- Check the headset for play by holding the front brake and rocking the bike forward and back, which can reveal a different source of clunking.
- Inspect and tighten fork mounting bolts, including the stem and lowers.
- If noise or stiction continues after cleaning and lubricating, the fork likely needs a full lower leg service, which involves changing internal oil and possibly bushings.
- A bike shop or suspension specialist can perform a lower leg service or send the fork to the manufacturer for servicing.
Tools and parts
- Clean rags
- Suspension seal lubricant
- Shock pump
Fork seal service kitSearch: “mountain bike fork lower leg service kit”
When to call a pro
A bike shop or suspension specialist can perform a full lower leg service, which is recommended annually for most forks under regular use.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.