Why Your Motorcycle Chain is Jumping & How to Fix it!


A jumping drive chain can have you guessing: Is it the sprocket? Or maybe the clutch? Is the chain worn down? Or maybe the sprocket themselves are worn down. It is an issue that is somewhere in the middle of a real brewing problem or maybe just a brand new chain that needs breaking in.

Whatever it is, an experienced rider knows that any kind of kink or strange noises coming off of your bike is not something to be ignored or even delayed looking in to.

Here is how it looks and sounds like:

  1. First, you put your bike on a middle stand lifting the rear wheel off the ground.
  2. Start up the engine.
  3. Engage the clutch and put it into 1st gear.
  4. If it’s an automatic, simply squeeze the throttle to spin the rear wheel.
  5. As the rear wheel spins faster, you begin to notice that the chain is making unusual noises and jumping from the top of the swingarm. It comes in spurts and later jumps regularly as you gun the throttle.

For whatever purpose, you begin to think that there might be something wrong with the chain or the sprocket. Any moving part that involves driving the bike to move forward is definitely a major cause for concern, and riders naturally react to it with worry, A broken or stuck chain could very well be the difference between your motorcycle flying off the road with or without you in it. It may sound morbidly funny but the danger is real.

Possible Scenarios

  • A stiff joint or joints in the chain.
  • Loose drive chain
  • Worn out chain or sprockets (front and rear)
  • Irregular engine hiccups

How to Fix a Jumping Motorcycle Chain?

Stiff Joint on the Chain

An improperly installed chain on a chain drive system may sometimes cause one or some of the links in the chain to lock up. It may cause one or two links in the chain to become stiff and immobile. Consequently, when that area catches a sprocket tooth, it jumps and causes some of the other teeth to lose contact with the chain.

It is possible that rust may have gotten to that link, or it may not be lubricated well enough.

If the link doesn’t have rust but is stiff for no reason, it may be a case of factory defect. Immediately replace the chain for safety reasons.

Steps:

  1. Inspect the stiff link (no need to remove the chain)
  2. If the chain link looks rusted and doesn’t look broken or deformed in any way, simply take a specialized lube for motorcycle bike chains and let soak.
  3. Once the link comes on loose and you have inspected all the other links to be ok, restart the engine and test run the chain again.
  4. The chain should no longer jump.

Loose Drive Chain

Every motorcycle depending on the model has its specified play when it comes to the tightness of the chain. Play means, the total measurement of how much your chain stretches upward when pushed with your finger.

Steps:

  1. Check your manual for the specified play of your drive chain.
  2. Test your chain’s play by pushing your finger upward against the bottom of the chain. Measure with a ruler.
  3. If the play is a match with the manual specification, move on to the next solution, the play is not the problem.
  4. If the specified play doesn’t match, then make the necessary adjustment by tightening the chain. To tighten the chain, you will have to make the adjustment by unlocking the rear wheel and pulling it back. Again, you may refer to your manual for proper removal. Note: Follow your motorcycle manual to its exact details. This is for your own safety.
  5. Once the tightening procedure is complete, test your chain by running your rear wheel with your motorcycle on a center stand. If the jumping no longer occurs, make sure everything is properly assembled, and then test drive your bike on the road. DANGER: Keep your eyes on the road! Use a GoPro or ask a friend to ride with you to look at the chain.

Worn Out Chain or Sprockets (front and/or rear)

If you know that you have not replaced your chain or its sprockets recently, chances are you have never replaced them, and you are using stock chain and sprockets (ones that came from the factory).

How to verify worn out chain or sprockets.

Steps:

Chain

  1. Check the recommended distance of the rear wheel from the front sprocket. Some motorcycles come with a marker on the swingarm for identification of the recommended distance of your rear wheel in relation to the front sprocket. It means that regardless of the condition of your chain there is a specified distance for your rear wheel to be set at the swingarm for the proper wear and tear of the chain.
  2. Once inspected and the proper distance verified, check: Is the play excessively loose? Does the chain have a sideways play? If the answer to both questions is yes, then replace your chain.

Sprockets

  1. Check sprocket teeth for wear and tear. More often than not, a sprocket due for replacement has a rather small and sharp worn out teeth. If you inspect it from the side you can see daylight where the chain and sprocket meet. normally you wouldn’t. And also notably, a sideways play to the chain indicates that the sprocket teeth have become sharp and thin.
  2. If any of the conditions in number 1 are present, and the chain is good, replace sprockets.

Replacing chain and sprocket set.

Depending on how long you had the motorcycle, its use, the mileage, and the frequency of replacements (if any). It would suffice to say for any of the conditions stated above on both chain and sprockets that may be present, it is highly recommended to replace the whole set. This is to ensure that there will be an even wear and tear on your chainset and enhancing the safety of your bike.

Once replaced, test drive on the hanger, then on the road, and if jumping persists check the engine condition.

Irregular Engine Hiccups.

Sometimes, a clutch situation may cause a hiccup in your motorcycle’s engine, this forces your chain to jump every time your engine hits a blank spot. This may either occur when your bike is being tested in the hanger, or when you are actually riding it on the road.

It could also be a possible engine combustion problem, especially if your bike for some reason may have been submerged in water.

Steps:

  1. Assuming that your chainset has been thoroughly checked and tested with no issues. Verify if it might be an engine issue. Listen for unusual sounds or hiccups.
  2. If its an engine problem, bring your bike to your nearest motorcycle service center. Preferably to your OEM.

Assuming that you might have tried everything short of disassembling the entire rear components of your motorcycle, and you still are experiencing jumps, there are two things that you can do. First, observe the chain when you test it on the hanger and when it is on the road.

Granted that you have already made all the necessary recommended adjustments to your drive chain set, watch your chain closely when you are testing it in the garage, and when you are actually riding it. There might be some possibility that when you are on it, the chain doesn’t jump.

This is for the reason that there are some motorcycle models that stretch their chain when the bike is loaded, and retract when the seat is empty.

So what happens is, your chain stretches when you ride your bike and relaxes when you’re not on it. If you are able to confirm that the chain jumping disappears when you are on the road, then you won’t have to worry. It’s just your chain play that is stretching and relaxing whenever your bike is in use. You can declare it as normal.

On the flip side, however, if the jumping persists with no other symptoms of bad chain or sprockets, then you can choose to do some DIY sprocket and chain set modifications. Word of caution: Do this only if you are an advanced rider or with some practical knowledge and experience on motorcycle mod.

Do not modify if you are a beginner to intermediate level. Any slight changes on any of the moving parts on your motorcycle can mean critical changes in the safety and rideability of your bike. Yes, it is a serious risk.

Otherwise, it is always best to consult your expert mechanic or your OEM service center. In the meantime, always practice good maintenance with your drive chain assembly and remember: The rear assembly of your bike is always exposed to the elements making it more prone to rust and dirt.

Always keep your motorcycle clean, and wash off any mud or dust that may have clung to it when you were using it. Periodically inspect your chain assembly for damage or defect, and make sure that your chain is lubricated with a special chain lubricant that is designed solely for that purpose.

Do not put any ordinary grease to your chain because it will collect dust and dirt which accelerates the wear and tear of your chain. If everything checks out well, it would be wise to not worry too much and just enjoy the ride.

Luka Barron

Motorcycle mechanic, writer and Heineken lover. A bit like Hank Moody on a Suzuki.

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