The chain on my Ninja 400 bike is coming loose

I’m really struggling here with my Ninja 400. The chain just won’t stay tight, and it’s starting to affect my riding. It’s loose again after just a few rides. Has anyone else had this problem? How do you keep the chain tension just right?

Response

I’ve had a similar issue with my Ninja 400. What worked for me was a combination of regular adjustments and using the right tools. It’s not too hard once you get the hang of it!

Solutions that Worked for Users

Solution	Users Who Found Success	Approx. Cost (USD)	Time Needed (Minutes)
Adjusting Chain Tension	4	$0 – $10	15 – 30
Replacing Chain and Sprockets	3	$100 – $200	60 – 120
Using a Rear Stand for Adjustment	2	$30 – $60 (for stand)	20 – 40

Symptoms

• Chain frequently becomes loose, even after recent adjustments.
• Noticeable slack in the chain, potentially causing it to skip.
• Unusual noises coming from the chain area during rides.

Possible Causes

• Chain tension not properly adjusted.
• Worn-out chain or sprockets needing replacement.
• Chain alignment issues.

Solutions that Worked

Adjusting Chain Tension

• What I Did: Regularly checked and adjusted the chain tension.
• Outcome: The chain maintained proper tension and stopped loosening frequently.
• Personal Experience: After adjusting, the ride felt smoother, and the chain noise reduced.
• Estimated Cost: $0 – $10
• Time Needed: 15 – 30 minutes
• Steps:
  1. Locate the Chain Tension Adjusters: These are typically near the rear axle of your bike.
  2. Loosen the Axle Nut: Use the appropriate wrench to slightly loosen the nut.
  3. Adjust the Tensioners: Turn the adjusters on both sides evenly to achieve the correct slack.
  4. Measure the Slack: Use a ruler or a specific chain slack tool to measure the slack, ensuring it’s within the recommended range (usually 20-30mm).
  5. Re-tighten the Axle Nut: Once the correct tension is achieved, tighten the axle nut back to the specified torque.
  6. Double-Check Alignment and Tension: Ensure the wheel is aligned correctly and the chain tension is still within the desired range.
• Expert Tip: Always adjust both sides of the chain tensioner equally to maintain proper wheel alignment. Also, after riding for a short distance post-adjustment, recheck the tension as it may settle.

Replacing Chain and Sprockets

• What I Did: Replaced the old chain and sprockets with new ones.
• Outcome: Significantly improved chain tension and overall ride quality.
• Personal Experience: The new chain and sprockets made the bike feel like new again.
• Estimated Cost: $100 – $200
• Time Needed: 60 – 120 minutes
• Steps:
  1. Remove the Old Chain: Use a chain breaker tool to remove the old chain.
  2. Remove Old Sprockets: Unscrew and remove the old sprockets.
  3. Install New Sprockets: Attach the new sprockets, ensuring they are properly aligned and secured.
  4. Thread the New Chain: Place the new chain around the sprockets and connect the ends using a master link or riveting tool.
  5. Adjust the Chain Tension: Follow the steps for chain tension adjustment.
  6. Lubricate the Chain: Apply a quality motorcycle chain lubricant.
• Expert Tip: When replacing the chain, always replace the sprockets as well to ensure even wear. Choose a high-quality chain for better performance and durability.

Using a Rear Stand for Adjustment

• What I Did: Used a rear stand to lift the bike for easier chain adjustment.
• Outcome: Made the chain adjustment process much easier and more accurate.
• Personal Experience: The rear stand provided better access and stability during maintenance.
• Estimated Cost: $30 – $60 (for stand)
• Time Needed: 20 – 40 minutes
• Steps:
  1. Place the Bike on the Rear Stand: Ensure the bike is stable and secure.
  2. Adjust the Chain Tension: Follow the steps for adjusting chain tension.
  3. Check for Proper Alignment: Ensure the rear wheel is properly aligned with the frame.
  4. Test the Adjustment: Spin the rear wheel to check for smooth movement and proper chain tension.
• Expert Tip: Using a rear stand not only makes chain adjustments easier but also allows for thorough cleaning and lubrication of the chain.

Motorcycle Models Where This Worked:

• Kawasaki Ninja 400 (Various Years)