8 Reasons Your Rear Bike Wheel Wobbles Side To Side (Plus Solutions to Unwobble)

It’s a frustrating problem that can occur on any bike: the rear wheel starts wobbling, and no matter how many times you try to tighten the axle or adjust the brakes, it just keeps getting worse.

So what’s causing your rear wheel to wobble?

Well, It could be a number of things, and it’s crucial to take action quickly to prevent further damage to the bike components and ensure safe riding.

In this guide, we’ll explore eight common causes of rear bike wheel wobble and provide tips on correcting each one.

How does it feel to Ride on a Wobbly Bike Wheel?

When you ride on a bike, your sense of balance is key. If that balance is thrown off by a wobbly wheel, it can feel pretty uncomfortable.

In fact, it can be challenging to keep yourself upright and moving forward when the wheel is unstable. This can be frustrating and even dangerous if you’re trying to ride in traffic or navigate a tricky path.

You feel like the bike wheel is just going to give up on you at any minute and send you crashing to the ground. If this is you, it’s time to learn how to fix a wobbly wheel.

But before that, you need to understand why the wheel wobble in the first place.

Causes of a Rear Bike Wheel Wobble

1.    The Bike Hub is Damaged

If your bike has a rear wheel wobble, the hub may be damaged. This is the most common cause of a rear wheel wobble.

When the hub is damaged, it can no longer hold the wheel in place securely, which causes the sides of the wheel to wobble.

Several things can damage a bike hub, including the impact of a fall, being hit by a car, or grinding against the ground while cycling.


Get the wheel and spin it to determine if the hub is damaged. If the wobble is still present, the hub is likely damaged.

To fix it, you’ll need a couple of thin wrenches to tighten the cones and locknuts on the outer surfaces of the bearings.

If the wobble is not present when the wheel is spun by hand, the problem is most likely caused by something else.

But if your bike has this hub problem, you’ll need to take it to a bike mechanic to have the hub repaired or replaced.

2.    The Bearings are Loose

There can be a few causes of a rear bike wheel wobble. Another common one is when the bearings are loose.

This means the axle can move up and down in the frame, causing the wheel to wobble.


The easy fix is to tighten the axle nuts if this is the cause, as it will help to keep the bearings in place.

3.    The Spokes are too tight or too Loose

Another cause can be tight or loose spokes. If they’re too tight, it can put too much stress on the hub and spokes, which can lead to them breaking.

If they’re too loose, it can also lead to a wobble in the wheel.


You should have the spokes tensioned adequately to offer enough resistance without putting too much stress on any part of the wheel.

If the spokes are too loose, try tightening the spokes.

If they’re too tight, loosen the spokes a bit. Keep in mind to turn the nipples slowly.

4.    The Tire Bead is Misaligned

One possible cause of a bicycle wheel wobble is an incorrectly aligned tire bead. When the tire bead is not perfectly parallel to the wheel rim, it can create excessive lateral forces on the wheel, which can cause the wheel to wobble.


You should reseat the tire bead and deflate the tire to correct this error.

5.    The Wheel is not Straight

If you’re experiencing a wobble in your rear bike wheel, the culprit may be an out-of-true wheel. An out-of-true wheel occurs when the wheel is not perfectly straight.

When a wheel is not straight, it will cause a wobble in the bike.

This can be caused by several factors, such as a bend in the wheel, misaligned spokes, or an improper spoke tension.

An out-of-true wheel can also cause the brake pads to rub against the rotor if your bike has disc brakes.


There are a few things you can do to diagnose and fix an out-of-true bicycle wheel.

One of the main ways to prevent or fix this issue is by ensuring your bike follows proper adjustments. This includes checking that your frame is aligned and that your tires are inflated to the correct pressure.

If you’re still having trouble fixing the issue, you can try a few other things.

One option is to adjust the angle of your seat or handlebars slightly. Alternatively, tighten the loose screws on your wheels.

You can also try truing the wheel. Remove the wheel and lace it on a truing stand. Then, spin it to find the wobble.

6.    The rim is too wide

If your bike wheel wobbles from side by side, the rim might be too wide.

When the rim is too wide, it creates a dish shape on the wheel, putting extra stress on the spokes. This additional stress can cause the spokes to twist and create a wobble in the wheel.


To fix this, you can try to adjust the tension of your spokes or get a narrower rim.

7.    The cassette is worn out

The cassette is the drivetrain part that attaches to the rear wheel. It’s responsible for transferring power from the pedals to the wheel.

The cassette is the drivetrain part that attaches to the rear wheel. It’s responsible for transferring power from the pedals to the wheel.

Over time, the cogs can wear out and start to wobble, which will cause your bike to shake and make it difficult to ride. When it’s worn out, it can cause the wheel to wobble from side to side.

One sign that your cassette is worn out is if you start experiencing excessive chain noise; if your bike starts making an annoying rattling sound every time you pedal, it could be because your cassette is loose and needs to be replaced.


If you have an older bike with a cassette, it’s essential to keep an eye on the condition of the cogs and replace them when necessary.

You can tell if your cassette is worn out by checking for excessive play in the gears or by listening for a clicking noise when pedaling.

If you’re having trouble riding your bike because of a wobble, try replacing the cassette and see if that fixes the problem.

8.    The brakes are misaligned

The misaligned brake pads can also cause your bike to wobble as you ride. This is because the brake pads are not hitting the same side of the rim on both sides.


To fix this, you will need to adjust the brakes’ alignment.

If you are unsure how to do this, take your bike to a local shop for assistance.

They will be able to adjust the alignment so that the brake pads hit the rim evenly, which will help to reduce or eliminate the wobble.

Can a wobbly rear wheel be fixed quickly and easily?

In most cases, this can be done quickly and easily.

The first step is to determine where the wobble is coming from. Often, it is easy to see if the wheel is off balance just by looking at it.

If it is not apparent where the problem is, try putting it onto a truing stand and begin to spin the wheel to find the wobble. Once you have determined the source of the wobble, you can try to fix it yourself or replace the tire.

Another option is to take it to a local bike shop and have them fix it. This is the best option, as they will have the tools and expertise to do the job correctly.

Is your bike’s wobbly rear wheel unsafe?

There’s nothing more frustrating than hitting a pothole and feeling your bike wobble uncontrollably.

But is this really an unsafe situation? Can a wobbly rear wheel cause you to lose control of your bicycle?

The answer to both of these questions is yes, a wobbly rear wheel can be unsafe. When your bike starts wobbling, it becomes more difficult to control.

This can easily lead to a crash if you’re not careful.

Closing Thoughts

If you’re experiencing a wobble in your rear bike wheel, it’s important to determine what is causing it. By identifying and correcting the cause of the wobble, you can hopefully eliminate it and enjoy a smooth and safe ride.

Thomas Kersten

Hi, I am a passionate biker, and I have been riding for more than ten years and share my biking tips and tricks with the world. I've tested more than 300 bikes.

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