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A lot of people face the problem regarding their front and rear sprocket being loose, which can cause wobble and damage to the chain and sprocket itself.
The front sprocket gets loose when there’s a loose-fitting of the nut and washer attached to the sprocket. The rear sprocket loosens up if the cush drive gets worn or damaged.
Riding style and conditions also affect the sprockets and chain. Motorcycles that are used for off-road purposes will encounter more dirt, grime, bumps, carrier load compared to street bikes/motorcycles.
So due to this sprockets will undergo a lot of friction and pressure causing issues like front or rear sprocket wobble, performance issues, chain damage, etc.
Motoxtasy Tip: Change your sprockets and chain at the same time. Changing only one of these will cause premature wear on the other component.
In this article, we will go through major aspects related to sprockets so you can get a better understanding.
What Causes Motorcycles Loose Front & Rear Sprocket
Both front & rear sprockets may become loose, which can cause harm to your motorcycle’s sprocket and chain.
Causes For Loose Front Sprocket
For the front sprocket of the motorcycle, the major cause for it to get loose is the nut and washer.
Let me explain, the washer or nut gets loose over time or due to excessive off-road riding or from the improper fitting of the nut and washer done while removing and fitting it again. Due to this, the front sprocket comes loose from the attachment which can cause serious damage to the chain and sprocket teeth.
Keep in mind a little movement of the front sprocket is acceptable and not to be concerned about.
Rust and corrosion will form if you avoid proper lubrication and cleaning of the front sprocket and the surrounding area, which will cause the nut, washer, and front sprocket to come loose from any kind of direct impact on it.
Off-road roughly used poorly maintained motorcycles will face this problem a lot.
How To Fix Loose Font Sprocket
Clean the front sprocket and the surrounding area with chain cleaner and look out for any rust formation.
Once the cleaning is done, see whether the nut and washer attachment is properly fitted ( if it is previously removed ). If you find some slack or loose-fitting with nut and washer, tighten it right then and there.
It’s that simple, but most people avoid proper routine chain and sprocket maintenance.
Causes For Loose Rear Sprocket
And if you are facing problems with your rear sprocket being loose, it’s due to worn cush drive ( rubber bushing ) or busted wheel bearings.
If the cush drive ( rubber bushing ) in the rear sprocket’s wheel hub is worn, it will cause the rear sprocket to become loose.
The rear wheel can wobble and move side to side if the rear wheel bearings are worn or damaged. This will result in overall poor wheel alignment, which in turn will cause the rear sprocket to move. This can cause the rear sprocket to become loose.
Also, check the nuts on the sprocket carrier plate to see if they are properly fitted.
A little bit of play ( movement ) is okay. But if the rear sprocket is moving side to side or up and down drastically, then it should be fixed as soon as possible cause it will damage the sprocket’s teeth and the chain rollers while compromising your riding safety.
How To Fix Loose Rear Sprocket
If the cush drive in the hub of the rear wheel is worn, it will create a higher amount of play in the sprocket.
Replace the cush drive rubber bushing with the new ones as it will dampen the impact inside the hub during sudden torque and breaking.
And if you have the cush drive in good condition, then you should take a look at the wheel bearings.
The rear wheel should be steady and should not have side-to-side movement on it.
If you see that the rear wheel has a wobble or drastic movement in it then check your wheel bearings because they might be damaged or worn out.
Deassmeble your rear wheel from the motorcycle/bike and remove the rear wheel seals. Then take out the spacer and worn/damaged wheel bearing out and replace it with new wheel bearings. This will eliminate the rear wheel and sprocket wobble which may have become loose because of damaged ball bearings.
Here’s an in-depth video from delboy’s garage on how to change wheel bearing.
Why Does My Front Sprocket Wobble?
The loose bolt/nut and washer that sits on the front sprocket will cause the front sprocket to wobble and also can make noise. Replacing the bolt/nut and washer can also fix things if the threads ( inner lining ) of the nut are worn or flattened.
After some time motorcycle’s sprocket teeth get flat. Once the teeth are flat or bent the front sprocket will start to make a crackling noise (kit-kit).
It is because the teeth of the sprockets are getting flat and the chain is freely spinning. This inconvenient noise is produced in any kind of motorcycle while it is in the first and second gear.
Since the torque is high at these gears, the rate at which sprockets rotate is also higher. You will not hear this kit-kit noise at a higher speed.
Replacing the front sprocket with the new one if the teeth on the sprocket are damaged or bent is recommended.
Tighten the nut and washer if it’s loose as the loose-fitting will cause the front sprocket to wobble and come loose. Also check the threads of the nut, if it’s worn change the nut and washer too.
Using these methods will stop the front sprocket to wobble.
How To Find Out If The Sprockets Are Worn Or Damaged?
It is very easy to inspect whether the sprockets are worn or damaged. A visual and audio inspection gives a clear idea of whether the sprockets are intact or replacement is necessary.
Method To Find Out If The Front Sprocket Is Worn Or Damaged
Method 1: Squeaking or Crackling Noise
Check if there is a crackling noise ( KitKit ) from the front sprocket. If the noise is present then remove the front sprocket cover if you have it on.
Method 2: Blunt Sprocket Teeth
Check whether the teeth of the sprockets have sharp edges, Sprocket teeth get blunt over time due to the constant impact of the chain on the teeth as metal changes its structure after constant impact or rotation of chain on it.
If the sprocket teeth are not sharp or have a bend, then it’s time to replace them with new ones.
Method 3: Visual Inspection Of Loose Front Sprocket
Engage the motorcycle in 1st gear on the middle or paddock stand and inspect whether the front sprocket wobbles.
If the front sprocket has a wobble, then the reason might be because of the loose nut and washer or the wear of the sprockets over time.
If the outside diameter of the sprocket teeth reduces, then the structure of the sprocket becomes uneven and it’s pretty easy to visually spot it.
Once all three steps are completed, then the vice decision can be made whether to fix the sprocket or replace it completely.
Methods To Find Out If The Rear Sprocket Is Worn Or Damaged
Method 1: Audible Sound From The Loose Rear Wheel Sprocket
First is the audio inspection, if you notice noise from the rear wheel sprocket, remove the rear wheel and disassemble the sprocket and hub.
Method 2: Bend or Blunt Rear Sprocket Teeth
Check if any of the teeth sprockets have a bend in them. Also, look for blunt edges of the sprocket’s outer diameter ( teeth’s edge ).
If you find any one of these signs, replace the rear sprocket with a new one immediately.
Method 3: Wobbly Rear Sprocket Or Wheel
Worn out wheel bearing will cause the tire to move from side to side which will cause the sprocket to not be in a stationary state. Due to this, the rotation of the chain and sprocket does not go smoothly.
Disassemble the sprocket from the wheel hub and remove the wheel bearing to check if it’s in the right condition. If it has corrosion or an uneven surface, then replace it with the new one.
Method 4: Worn Cush Drive Causing Damage & Resulting In Loose Rear Sprocket
If the cush drive is worn, it will not provide a reliable cushion inside the wheel hub.
The rubber layer of the cush drive should be even not be chipped. Replace the cush drive rubbers/dampers with the new one as soon as you can
So look out for these indicators by using the methods we have given, which will help you find out if the front or rear sprocket is worn or damaged.
How To Tighten The Front And Rear Sprocket On The Motorcycle?
For the motorcycle to be safe while riding, the sprockets should be in optimal condition and shouldn’t have any loose-fitting in them.
So here are the easy steps to tighten the front sprocket.
Steps To Tightening Front Sprocket
- First, remove the front sprocket cover and disassemble the front sprocket with washer and nut and clean it thoroughly.
- Now put back on the cleaned front sprocket on the output shaft.
- Place the washer on the center of the sprocket.
- The nut goes on the top of the washer. Tighten it with the help of a ring spanner or the t-spanner.
- While tightening the nut you should rotate the spanner clockwise as the front sprocket rotates in the counterclockwise direction.
- Pin or hold the chain in place while tightening the nut. Use the recommended torque to tighten the nut by referring to the owner’s manual.
- And that’s how you tighten the front sprocket.
Now here are the easy steps to tighten the rear sprocket.
Steps To Tightening Rear Sprocket
- First place the rear wheel and the sprocket in between the swing arm or parallel to the swingarm for bikes/motorcycles with a single swingarm.
- Remove the rear wheel with the help of a t-spanner or ring spanner.
- Now tighten the bolts which keep the rear sprocket in its place.
- Install the rear wheel back on the motorcycle.
- Be careful while inserting the axel back into its place. As it should go straight into the slot and through the wheel.
- Align the wheel in between the swing arm like before.
- Place the chain on the sprockets and align the wheel.
- Once everything is aligned tighten the rear nut with the help of a ring spanner or t spanner and the vehicle is good to go.
Conclusion
So take care of the sprocket and chain by following proper lubing and cleaning routine. If you see the front sprocket loose, check the nut and washer. The rear sprocket might come loose due to loose blots which hold the sprocket or worn cush drive or busted wheel bearing.
Look out for these significant signs to fix the loose front and rear sprocket.
