There’s actually nothing more concerning for us cyclists than when you’re moving along down the road and start to feel your bike vibrating whilst pedaling. You slam on the brakes. You have a quick look at everything, and all seems fine. But when you start off again, that vibrating is back, and you don’t know what’s causing it. Sounds familiar?
Well, if your bike has been vibrating when pedaling and you want to fix the problem, then you’re in the right place. But let us warn you, it’s time to clear your afternoon because the number of possible causes is seemingly ENDLESS.
There following can all be reasons behind your bicycle vibrating when pedaling:
- Bottom bracket may be worn
- Bottom bracket may be too tight
- Sprocket and chain may be worn
- Chain may need additional lubricant
- Check for a faulty rear wheel bearing
- Pedal bearings may be worn
- Derailleur jockey wheel bearings may be messed up
- ANY of the above components may be moving sideways – and they shouldn’t be
- Headset may be loose
- You might have an egg-shaped wheel
Hey, we said it was endless, didn’t we? To help you understand what may be going on, we’ll cover each of the possible causes below, talk about why they might be the problem, and then suggest a fix. By the end of today’s post, you should have come across the reason for the vibration and be able to fix it.
Bottom Bracket Issues
To find out if the bottom bracket is the problem, you have two options. Unfortunately, the most likely one is also the most complex, and that’s that the bottom bracket is worn. To find out if it is the problem, you’ll need to do a few tests. So, here’s what to do.
Remove the chain and put weight on the cranks horizontally, then move 180 degrees and put your weight horizontally. If you can feel an issue, then the bottom bracket is the problem. This usually indicates that it’s worn, which is common on older bikes.
When it’s worn, it causes vibrations because it’s a bottom bracket’s job to connect the chainset to the frame and allow the cranks to turn smoothly. If it’s unable to do that smoothly, you’ll feel it on your bike as the whole thing vibrates.
To fix the above problem, you have only one option: replace it. The bottom bracket might not be worn, just loose. You can try tightening the main fixing bolt with a torque wrench to the proper specification for your bike (or have someone at a local bike store do this for you if you don’t have the tools).
Try greasing the bearing too, and tightening the other stack bolts with an Allen key to fix it in place properly. If those fixes don’t work, though, then the bottom bracket is worn and you’ll need to replace it.
But be warned, because the second most likely explanation is that on these cartridge bottom brackets, the main fixing bolt and stack bolts are actually too tight.
If the bottom bracket is fixed too tightly, then you’ll also feel a vibration. This is especially true of the main fixing bolt because if it isn’t to the right torque, it’ll be putting a lot of pressure on the frame, making it vibrate.
So, if the bottom bracket isn’t worn, try loosening the bolts just a little. If the cranks can turn more freely now, then the bike shouldn’t vibrate.
Sprocket And Chain Faults
Moving on to the sprocket and chain now, these are obviously integral parts of what makes your bike move, so if there’s a problem when pedaling, it’s probably best to check these as a matter of urgency.
And a worn sprocket and chain are known for causing vibrations. But thankfully, knowing if this is the fault is pretty easy to check.
All it takes to determine if the sprocket and chain are worn out (or even the whole chainring and drivetrain) is a quick visual inspection. That, and knowing how long the sprocket and chain have been in use.
Of course, sprockets should last longer than chains as a general rule anyway, since they have a longer lifespan, but checking them is simple enough.
Concentrate on the chain first. All you have to do is put your bike in a gear so it’s in the big ring and the smallest gear on the cassette. If you then grab the chain at the front and lightly pull it, you’ll be able to tell if the chain is worn.
Does it lift off the chainring teeth with little effort? If so, then it’s worn because the chainring teeth can no longer grip it like it’s supposed to. That means a looser chain, and more vibrations whilst pedaling. The good news? All you need to do is replace it.
Next, try the sprocket. You’ll see a problem here right away if there is one. Look at the sprocket teeth. Is there a polished, worn strip on them? If so, then it’s likely the sprocket is worn too. This will need replacing.
If your whole drivetrain is worn, then the vibration you feel whilst pedaling is a warning to replace it quickly. A worn drivetrain, sprocket, or chain can be a real danger on the road, so make sure nothing is wrong with the drivetrain before moving on.
Another good tip, if everything seems to be in working order and isn’t worn, is to check if the chain is lubed properly.
If it isn’t, apply some more because if your chain isn’t lubed, it can’t move around the chainring teeth as smoothly as it should be, and that can create an uncomfortable vibrating whilst pedaling, too.
Bearings And Their Bugbears
Bearings are an essential part of your bike’s movement as well, so this is another good place to start. It’s a bearing’s job to help your bike spin, so if the problem you’re noticing is only whilst pedaling, it’s a pretty good chance that there are bearings involved that are causing your bike to vibrate as you move.
Unfortunately for you, there are bearings in your pedals, wheels, headset, and bottom bracket – and any of them could be the problem.
Thankfully, some are more likely than others, so we’ll cover those more common issues now.
Your first port of call needs to be your rear wheel. If you have a bad rear wheel bearing here, then it will almost certainly make your bike vibrate.
To check if it needs replacing because it’s bad, you’ll need to lift your rear wheel so it’s suspended in the air, and then bring around your wheel so the heaviest part (usually where the valve is, since there isn’t often a lot of weight on bike wheels these days) is at 3 o’clock.
With the valve part of the wheel at 3 o’clock, simply let go of the wheel. If it drops to 6 o’clock smoothly, then your wheel bearing is fine. If it’s shaky or unsmooth, or struggles in any way, then you’ve got a bad rear wheel bearing. Fix this by loosening it slightly (tight bearings will cause vibration) or replacing it entirely if it’s worn.
Speaking of worn bearings, pedal bearings get worn quite easily because of all the work they do, and this can make the bike vibrate whilst pedaling, so check these too. If the pedals don’t turn freely and smoothly, then the bearings are likely worn.
You can attempt replacing these yourself, but you’ll need to remove the whole pedal to do so. If that isn’t something you feel comfortable with, then take your bike down to a local bike store and ask them to replace the pedal bearings for you.
A problem with your derailleur jockey wheel bearings is almost always more obvious than the other two, because in addition to the vibrations, you’ll hear some squeaking whilst pedaling too.
If you can’t change tension properly or your shift quality drops, then the derailleur jockey wheel bearings are likely messed up. It could be that they’re worn, or they need regreasing.
Now, to fix this problem yourself is quite technical, and will involve using a vice and bushings to push the derailleur jockey back together once you’ve taken it apart with the flat side of a small knife.
This can result in breaking it if you aren’t careful, so rather than talking you through derailleur jockey wheel bearing replacement or regreasing, we’d feel more comfortable if you took it to a local bike store to talk about fixing it, because it’s just too risky otherwise.
A Note On Moving Sideways
One thing you should always be wary of is your cranks moving sideways. In fact, you should be wary of that and ANY of the parts we’ve discussed so far today moving sideways because that sort of horizontal movement isn’t good.
It will definitely cause your bike to vibrate because the sideways movement isn’t natural, and whilst pedaling, that can be very uncomfortable.
Thankfully, if there is a sideways movement on any of the parts, it’s because of one of two things:
- The part is worn
- The part is loose
That means you can try a few different things. First, start by tightening anything that’s moving sideways that shouldn’t be. Does that fix the issue? If so, happy riding, you shouldn’t feel any more vibration whilst pedaling. But if tightening them doesn’t help, then the part that’s moving almost certainly needs replacing.
We also just want to highlight that in the case of cranks, you should always try tightening the crank bolts first to see if they move sideways anymore.
If they still do, then you’ll need to replace the bottom bracket, as this is likely worn and causes the cranks to have that sideways movement, which is causing the vibrations when you ride.
Your headset is the component that provides the rotatable interface between the bicycle fork and the head tube of the bicycle frame.
It basically allows you to steer, so if this is loose, you’ll definitely notice the vibrations whilst you’re pedaling. The easiest way to tell if this is indeed the problem is to steer a little more whilst you pedal. Are the vibrations worse? If so, then the headset is probably loose.
To make sure it is loose, stand beside your bike and hold the rear brake with one hand and move the bike back and forth. Put one finger of your other hand over the headset and feel for any movement. If there is any, then it’s loose. All you’ll need to fix it is an Allen key, though!
There are typically 3 bolts in a headset, 2 at either side, which are the stem bolts, and 1 on top, which is the main headset bolt. Start by loosening the 2 side bolts or stem bolts just enough to be able to move the handlebar separately from the front wheel.
Now, you’ll need to tighten the main headset bolt, but not too tightly. Use only one finger on your Allen key to tighten it until you can’t move it anymore. This is enough to stop the vibrations and keep your headset in place, but it won’t cause your steering to be stiff or put too much load on the bearings.
After that, tighten the stem bolts back up again, and your headset problems should be fixed.
An Egg-Shaped Wheel
Finally, one other problem might be that your wheel has bent out of shape. If it is egg-shaped, then you’ve got a problem.
If a wheel isn’t the right shape, then it can catch on various things as you ride, and pedaling will cause it to vibrate as it tries to turn on a shape that’s ill-suited to turning smoothly.
You’ll be able to tell if your wheel is egg-shaped because, well, it’ll look like an egg. And to fix this problem, you’ll simply either have to replace the wheel entirely or try truing your wheel at home to get it back into shape.
The second option might take more time, but it’s much more cost-effective, and knowing how to true a wheel is a good habit to get into as a cyclist.
Well folks, that’s all we have for today’s post! But this comprehensive guide to fixing your bicycle vibrating whilst pedaling ought to contain the answers you’ve been looking for. Remember, if it’s worn, replace it, if it’s loose, tighten it, and if it’s tight, loosen it, and you should be able to fix the issue pretty quickly.
Either way, we’re confident that whatever the problem is can be fixed by following today’s guide, so all that’s left for us to say is have fun figuring out which problem it is and fixing it.
And if you’ve been trying the fixes in order and following along with our post and it turns out the problem is the egg-shaped wheel, well, we’re sorry we included it last… Happy riding, anyhow!