Hearing a knocking noise when pedaling bike can be both alarming and agitating. It sounds as if someone is tapping ever so lightly on the bike’s frame with a hammer.
But what’s causing that bike noise, exactly? And how do you go about fixing it?
In this post, I’ll highlight the possible reasons behind the knocking noise you keep on hearing when pedaling, then point out what you need to do to fix the problem.
Components to Check for the Source of Knocking Noise
Unfortunately, there’s more than one component that might be causing the knocking noise you’re hearing. So, you might want to free up an hour of your time for a thorough investigation.
Here are the components you need to check:
Derailleur
The first component you want to check when you hear a knocking/clicking noise while pedaling is the derailleur, particularly the pulley wheel.
If you’re hearing the knocking noise 8-10 times per pedal revolution, it’s highly likely that one of the sprockets in the pulley wheel is deformed or broken.
Fixing this problem will require a new pulley wheel, assuming the sprocket’s deformity cannot be mitigated.
Frame
Next, you want to check the frame of the bike, particularly the derailleur hanger. This is a component that’s fixed to the frame of the bike, and that hangs down slightly so that the rear derailleur attaches to it.
The hanger should hang straight so that the pulleys of your derailleur system are in line for smooth changing. If it’s not straight, the pulley system can come out of line, resulting in knocking noises.
The solution in this scenario is to adjust the hanger’s alignment by simply bending it into place. That said, if you notice that the hanger is damaged due to excessive bending, it might be time to replace it.
Apart from the derailleur hanger, make sure that all bolts and rivets are tightened properly, especially the ones at the seat post and the water bottle cage. it could be that the bottle cage is loose and rattling.
Bottom Bearings
Another possible reason you keep hearing a knocking noise when pedaling is dirty or dry bottom bearings. You might even hear creaks or squeaks if you’re pedaling intensely.
The solution to this problem is quite simple. All you have to do is add some grease to your bike’s bearings. I’d also recommend adding grease to the chains to ensure smooth functionality.
Pedal or Crank Arm
Next, you want to check your pedals. They might be loose causing clunking noise. Just need some light maintenance like cleaning, greasing and tightening should solve this issue.
The first thing you want to do is remove the pedals. Then, clean the pedals and the crank arm before you start greasing them. Lastly, install everything back into place and make sure everything is adequately tightened.
Headset
Under heavy braking, a loose headset is bound to make some knocking or clicking sound. This also happens when you’re in a sprint or when standing up during a climb.
To fix a loose headset, you need to check the preload of the bearings, making sure they’re tightened properly. If there are any corroded or worn bearings, you’ll need to replace them.
Additionally, make sure that all the points with which the bearings come in contact are clean. And lastly, check the stem faceplate bolts and ensure they’re firmly in place.
Cassette / Rear Hub
Another component that might be behind the knocking or clicking noise you hear when pedaling is a loose cassette. With that in mind, you need to make sure the cassette is tightened to the proper torque.
If your cassette has a pinned carrier, ensure the pins are well-lubricated. Otherwise, you may hear some creaking or squeaking noises that are just as annoying as the knocking sound.
It’s also worth noting that your bike’s rear hub might be a culprit, too, especially if your bike is on the cheaper end. Cheaper bikes, like the Hyper SpinFit, tend to have an overly-compressed rear hub, which forces the ball bearings to make unwanted noises.
Unfortunately, this scenario doesn’t have a solution other than opting for a better cycle.
To confirm that this is the situation you’re dealing with, I recommend heading to the local bike shop from where you bought your bike and checking if they still have the same model for sale. If they do, take one for a ride to see if it has the same issue.
Suspension for Any Wear and Tear
Lastly, your bike might be making some knocking noises due to general wear and tear. This might be the case if you’ve been using your bicycle extensively for a long time.
To deal with this problem, inspect the frame for cracks, especially near the bottom bracket shell and the dropouts. If there’s any flaking paint, you’ll want to remove it.
Check the cable guide for anything that’s out of place. I recommend reinstalling the guide and tightening it well.
Another thing you should do is check the shift housing and ferrule interface. Due to wear and tear, the housing might start rubbing against the ferrule, which can produce unwanted noise, especially when turning the bars.
If the housing and ferrule are notably damaged, you’ll need to replace them.
Wrapping Up
Hearing a knocking noise when pedaling a bike can be extremely annoying. However, it can also indicate an underlying issue with your bike that needs to be addressed.
Hopefully, with the information shared in this post, you’ll be able to pinpoint the cause of the knocking or clicking noise problem and deal with it.
