There are multiple solutions on how to fix a bike pedal that fell off. Some involve replacement parts, while others just some elbow grease.
The bike pieces involved in this issue are few. Your pedal is not connected to the crank arm anymore.
Why does a bike pedal fall off?
The point of contact of the pedal and the crank arm are the threads, so that’s the culprit in most cases. Damaged threads appear by cross-threading. That happens when trying to thread the pedal at an angle. Or not screwing the whole way leaves the pedal some wiggle room to do some damage. The other reason would be a damaged crank arm, which requires a replacement.
If you’re lucky, the bike pedal got unscrewed, so the solution is to screw the pedal back in. In most cases, there’s something more wrong than that. Meaning destroyed threads or a damaged crank.
Are there different pedals or crank arms?
Yes, there are a couple of different cranks. The threads are different so be careful and know which one you have.
|One-piece (American) Cranks||1/2″ (0.50″) x 20 tpi||12.7 x 1.27 mm|
|Standard-3-piece cranks||9/16″ (0.56″) x 20 tpi||14.28 x 1.27 mm|
|Old French||0.55″ x 20.32 tpi||14 x 1.25 mm|
|Dyna Drive||1″ x 24 TPI||25.4 x 1.06 mm|
You can see what thread size you have, by checking the inscription on the pedal or the crank.
Are the pedals the same for both sides?
No! The left pedal has an opposite thread. This is an intentional thing. The left pedal kept coming off bikes since pedaling would unscrew them after some time. Almost all pedals have a small “L” or “R” written on them somewhere.
How to fix it step by step
There are many causes for a bike pedal to be falling off, so there will be many solutions for this issue.
Case #1: Broken Crank
This one is a bummer. There is no solution here other than to buy a new one or take advantage of your warranty if you’re still eligible. The problem could have appeared by applying more force than it could handle. Either by stomping on it or neglecting the bike and letting it fall on hard surfaces.
Case #2: Crank or pedal have damaged threads.
First thing’s first: if the pedal threads are gone, the pedal needs a replacement. No way around it, unfortunately.
If the pedal is fine, you need to check how well the crank arm threads are. Try taking the other pedal off and compare the threads between them with your hand. Or with any tool to see the depth of them. If they’re not the same, there are a couple of ways of fixing it.
If there is damage on the front crank threads, you can try a quick hack to fix them. Install the pedal from the back to realign the front threads to their initial state.
If you like tinkering, the do-it-yourself solution is to buy a crank pedal tap to make new threads. What that does is it cleans the hole and then creates new threads. Now the oversized hole is not suitable for a pedal. There is a second part needed called a threaded insert. You need to screw that in first while using some thread locker to keep it in place, and only then can you install the pedal. Be extra careful when making new threads, the angle needs to be straight.
The second option would be to replace the damaged crank arm. A replacement doesn’t cost much, so try to buy 2 of them to have the same model on both sides. There’s an estimated price below.
Case #3: Pedal fell off.
If this is your case, you’re very lucky and the solution is as simple as screwing it back.
Check the threads using your hands or a screwdriver before screwing and do some cleaning. Optionally, with the help of a file, you can fix some of the possible damage.
Next, apply some grease to the threads before starting. Use your hands to start the process of screwing the pedal in place. Be careful not to force it in and overdo it. A quick note here is that it is easy to screw the wrong pedal since the aluminum crank arm is malleable. So be careful and screw the first few times by hand. Finish the job by using a wrench. Be sure that you can untighten your pedal at a future time if needed.
What to look for when buying a new bike pedal?
First thing is to look for what type of pedal you want. There are two main types of pedals, clipless and flat pedals. They both fit on the crank arm you have, so the only thing left is to find out which one suits you best.
Second thing is to look at what insert does your crank arm has, to buy compatible pedals. You can search above how to find the thread size for your pedal.
How much it costs to replace everything?
Of course, there are different price ranges for different models. So here is the smallest cost of a replacement:
- New Pedals – $10
- Crank Arm – $10
You would need to consider buying 2 crank arms to have the same model on both sides. This is for purely aesthetical reasons, so you do you. Going the do-it-yourself route, here’s the cost of the tools you need:
- Pedal Tap and thread inserts kit – $22 – Amazon Link
The cost of lubricant or other general tools needed is not included as they’re not exclusive to this fix.
How to take care of bike pedals?
After every bike ride, use a wet cloth to remove any dirt or debris from the pedal. That way you will see if there is any damage made to its structure and if there is something you need to worry about. By doing this, you will take care of the bearings inside and have a longer use from your pedals. If you own a pressure washer you can use the lowest setting for the cleaning.
For clipless pedals, a grade of concern would be when clipping in becomes harder than before.
Some side notes
- If you’re far from home and the pedal fell off, try jamming some paper in there. Or some dirt for the extra temporary seal until you get hold of some tools.
- There should be no limit to how many times you can take out and change a pedal. As long as you clean and apply lubricant each time and don’t over-screw.
Regardless of the reason behind your pedal falling off, this is not a big issue to have. Worst-case scenario, a few bucks for a replacement will fix your problem.