Why Do My Bike Pedals Wobble – Bicycles In Motion

Why Do My Bike Pedals Wobble

Why Do My Bike Pedals Wobble

Have you ever been cycling along and feel like you are not getting the power you need? The problem may not be you and you should be asking why do my bike pedals wobble?

Pedals are important parts of the bike. Without them, your feet do not have a place to properly propel the bike forward. There are several reasons that your pedals could be wobbling, from the brackets being loose or the pedal crank being damaged to a pedal hitting the bike frame. Identifying the cause is important, if you want to be out on the road.

Pedals get the entire bike motion moving, turning the chain and wheels so you can go. Using my guide, you can identify the reasons your pedals are wobbling and get them fixed sooner rather than later. Wobbly pedals means your feet can slip or you just won’t get the power you need. And then you’ll be going nowhere.

Recommended Gear

To see all of my up-to-date recommendations for bikes and cycling gear, check out this resource that I made for you!

7 Best Mountain Biking Destinations...
7 Best Mountain Biking Destinations In The US

Loose or Damaged Bike Pedal Crank

The bike pedal crank arm is what connects the pedal to the crank which is the piece the chain is attached to. The stability of the pedal crank can affect the stability of the pedals.

A common reason for wobbly pedals is a loose or damaged bike crank. The screws that attach the crank arm to the crank and to the pedals can be knocked loose when the bike falls. Or they can loosen over time.

The crank can become damaged if you pedal while it is loose. This only makes the pedals more loose and likely to come off. It is easy for crank threads to become worn because they are made from soft aluminum while pearls are hardened steel.

If the threads are worn, tightening will not fix the issue. You will need to get to a bike shop where they can drill out the threads. They will put in slightly larger ones and insert a helicoil that will allow the pedal to fit again properly.

Loose or Wobbly Bottom Bracket

The bottom bracket on a bicycle can also influence the pedal. This bracket connects the crankset to the bicycle and allows it to rotate smoothly. There is a spindle within the bracket that attaches to the crankset and bearings that let the cranks rotate. Pedals attach to these cranks.

Bottom brackets can become loose over time and when they are not securely locked in place, the crank and pedal will wobble. Improper tightening can cause the locking threads in poor condition and if damaged they will not secure the bottom bracket.

Alternatively, an accident or damage to the bike can cause bearing to become loose within the bottom bracket. This interferes with spindle rotation and pedal stability.

A loose or broken bottom bracket will sound like a rhythmic creaking as you ride along. If the locking threads are not damaged, you wimpy need to tighten the bottom bracket cup to secure the pedal.

First, you need to loosen the lock ring, then tighten the bottom bracket cup until the crank is moving smoothly. Holding on to the bottom bracket cup, tighten the lock ring.

Bent Chainring

The chainring is another potential cause of a wobbling pedal. The chainring impacts your bikes gearing and is directly attached to the cranks which have the pedals attached. With regular riding, the bolts that hold the chainring securely in place can become loose.

In some cases, they fall out. Early signs of this will be a wobbling pedal, but if not caught in time, you will hear a big crunch mid-ride and the bike will just stop.

If you notice that you have pedals that wobble, check the bolts of the chainring to make sure they have not come loose. A loosened chainring will move as you pedal which will only further loosen the bolts.

If the chainring moves as you pedal, the pedals will shake or wobble too as they are connected through the crank arm. One loose component of this system will impact the others.

Serious damage to the bike can cause the chainring to become dented. This usually only happens if the bike is dropped a lot or involved in an accident. A bent chainring will need to be replaced to prevent wobbling. If it is just loose, then tightening the bolts will secure it and prevent the pedals from wobbling.

Bike Pedal Hitting Frame

If it feels strange to pedal and you are hearing a “clank” sound, then the pedal could be hitting the frame. This typically happens if the crank arm is bent in any way.

A bent crank ark brings the pedal closer to the frame of the bike so as it rotates it may hit the frame. It may not feel like a wobbling pedal, but you will definitely notice that the pedal is not straight.

A pedal can itself get bent if dropped which can also cause it to hit the bike frame each time you pedal. Not only will you hear and feel the pedal hitting the frame, but it should be obvious to see upon looking.

While the bike is standing upside down, rotate the pedal using your hand to check if it hits the bike frame. You will need to replace the crank arm or pedal depending on which part is bent. For slight dents, a bike shop may be able to straighten out the parts for you.

Loose Bearings

Loose bike bearing can cause several parts of the bike to become loose and wobbly. The bearings used to keep the wheelchair and crankset secure are integral to also keeping the pedal secure. If any of those parts are loose, the pedals attached to them will become loose too. Bearings become loose over time so need to be checked regularly.

Without checking them, not only can the pedals wobble, but you risk damaging the crankshaft or chainwheel should they become too loose. Those are more expensive to replace, so it is better to get in the habit of checking bearings frequently to make sure they are tightened.

You also need to make sure you do not over tighten the bearings as this can cause too much restriction to movement which can also damage the pedal mechanism. You can inspect the bike bearings to see if they are worn and need replacement. When worn out or dry they will feel rough and metallic.

A dry bearing will prevent the axle from spinning. Rubbing your finger across a dry bearing will make the axle stop completely. If this happens, the bearings just need to be greased.

Helpful Tips To Know What Causes Bike Pedals To Feel Wobbly

A wobbly bike pedal can be caused by any number of things. They can also be easily avoided by regularly checking your bike and the components linked to the pedals. To properly identify the cause of the wobbly pedals, there are a few helpful tips to remember.

  • Listen for sounds as you pedal. Grinding noises and clanking noises indicate different problems as laid out in the previous sections.
  • Visually inspect the bike for any obvious signs of damage or denting
  • To get the best look at all the moving parts, turn the bike upside down for a closer inspection.
  • Practice regular bike maintenance because when anything is out of place or not working properly you will be more aware of where the problem may be.

Final Thoughts

Bikes are designed for activity, so they will get damaged and they will get worn. Even with quality parts and construction the parts of a bike can wear down or loosen from vibrations, dirt, and incorrect tightening. If any part attached to the pedals comes loose or gets badly damaged, the pedals will also get loose.

So, if you are wondering why do my bike pedals wobble? Use my guide to take a closer look so you can get things tightened back up before the pedals come off and you are stuck going nowhere.

Brian Smith

Brian is the founder of Bicycles In Motion and an avid cyclist for 17 years. On the weekends, he enjoys exploring new bike trails and countryside roads to enjoy the outdoors.

Recent Posts