How to Fix a Bike Chain

Dealing with a slipping, broken or rusty chain can grind your bike rides to a halt. But learning how to fix a bike chain yourself will keep you rolling smoothly for miles. This DIY guide covers adjusting chain tension, lubing, cleaning and replacing chains on any type of bicycle.

Checking Chain Tension

Start by checking chain tension regularly:

  • Shift to the smallest cog and chainring
  • Inspect the lower section of chain for sagging
  • Ideally it should have only subtle up/down play when lifted
  • Significant sagging means the chain is too loose
  • Turn pedals and chain should run smoothly without binding

Keeping chain tension adjusted prevents premature wear and damaged gears.

Lubricating the Chain

Lubricate your bike chain every 100-200 miles:

  • Clean chain thoroughly before lubricating
  • Choose a quality bike-specific lubricant
  • Apply lubricant to each link pin while pedaling slowly
  • Thoroughly work lubricant into all of the rollers
  • Wipe off any excess lube with a rag
  • This keeps your chain running quietly and efficiently

Proper regular lubrication prolongs your drivetrain’s lifespan significantly.

Cleaning a Gunky Chain

Follow this process to clean a dirty, muddy chain:

  • Remove the chain by opening the master link
  • Soak the chain in degreaser solvent for 15 minutes
  • Gently scrub with a small brush to remove grime
  • Rinse well with fresh water and dry thoroughly
  • Check for sticky links that may need extra cleaning
  • Once fully dry, re-lubricate before reinstalling

Keeping your chain clean means lubricant works better and moving parts last longer.

Replacing a Worn Chain

Replace your bike chain once it reaches 0.5-0.75 chain wear elongation. Check by:

  • Using a chain wear gauge tool
  • Note when links no longer sit flush in the gauge
  • Chains also feel loose and gears may slip under load
  • Very worn chains will actually stretch visibly
  • Replacing chains before they’re too far gone saves your drivetrain components

Swapping for a new chain improves shifting performance and saves your cassette and chainrings.

Removing a Snapped Chain

If your chain breaks or snaps mid-ride:

  • Locate the quick link securing the chain
  • Use a chain tool turn the locknut to loosen the link
  • Unthread the link pin to separate the two ends
  • Remove the damaged section of chain
  • Collect the detached links to measure new chain

With part of the chain removed, you can shorten and rejoin it to limp home.

Joining a Broken Chain

To rejoin a separated or shortened chain:

  • Determine how many links needed to bridge broken ends
  • Use a master link, quick link or new chain pin
  • Insert ends into link and tap pin back in place
  • Ensure link moves freely after reconnecting
  • Replace quick link locknut or crimp new pin
  • Check that chain can pass through derailleurs after reinstalling

Carrying master links and extra pins allows trailside chain repairs to get rolling again.

Identifying Chain Compatibility

When replacing a worn chain, match:

  • Speeds – 6, 7, 8, 9, 10, 11 etc.
  • Type – wide, narrow, 3/32″, 1/8″ etc.
  • Brands often recommend their branded chains
  • But any compatible new chain of equal width works
  • Bring the old chain to compare width and link shape
  • Or count the rear cogs if the old chain is missing

Using the right replacement chain prevents shifting issues.

Installing a New Chain

To install a new chain properly:

  • Size the chain by matching length of old one
  • Break the chain at the pin using a chain tool
  • Loop the chain through the rear derailleur pulleys
  • Pull ends together and connect with master link
  • Ensure link locknut is tightened securely
  • Check derailleur alignment in highest/lowest gears

Taking time to size, join and align a new chain correctly will pay off through smooth shifting performance.

Troubleshooting Chain Issues

If your chain is problematic, try:

Slipping – Replace worn chain, lube/clean links, check cassette and chainring wear

Noisy – Lubricate and clean links, replace damaged rollers

Stiff Links – Flush dirt out with degreaser, flex links to loosen, lube

Jammed – Remove link obstruction, lube sticky pins/rollers

Won’t Shift – Replace excessively worn chain, realign derailleurs

Addressing small issues promptly prevents bigger mechanical problems developing.

Learning to properly service and repair your bike chain will keep you riding nonstop for thousands of miles. Just take chain care step-by-step. Let us know if you have any other chain maintenance tips!

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