Bike Pedal Fix

75K308

Intro: Bike Pedal Fix

During a recent bike ride my son went to pedal after walking across a section of grass, and as he did his pedal just dropped out from under his foot. It must have been loose, working its way out, and when he pushed down it ended up stripping out the threads, making it difficult to screw and tighten back in. The following steps is not ideal, but it will work well for a long time. I hope it helps. (Note: I also used this chance to have my son learn how to do some repairs.)

STEP 1: Materials

-The un-attached pedal
-Correct size wrench, in our case 5/8ths
-Small file
-Pick (Since I do not have the tools to re-thread properly with a tap and die set)

STEP 2: Cleaning the Threads Out of the Crank Arm

Using the pick clean up the inside threads to clear any significant obstructions, it will help also to help where the threads were smashed down to open them back up. Also you will want to pull out the threads that were broken out, be careful there are metal slivers and can hurt.

STEP 3: Pedal Threads Clean Up

This step may not be necessary but it can help. Using the small file using the good edge go around in between the threads, and make sure they are smooth, be careful not to take off points of them you will want them to bite in.

STEP 4: Screw the Pedal Back In

This step may take a little bit, it takes some wiggling and working to get the threads started, but since some were stripped out of the crank arm, it proved impossible to align it all back up so we got it started the best we could.

STEP 5: Tighten the Pedal

Pretty self explanatory but a good note to know is the to tighten a left side pedal you have to dis regard the good old saying "Righty Tighty, Lefty Loosey" since on a left pedal the threads are reversed. Since the threads were pretty messed up we had to really crank the pedal down since at one point we were cutting new threads, but we got it tight and it will hold for awhile. Also if you want you can use a product like a mild thread locker, which I could not find my bottle at the time we did this.

STEP 6: Good Luck

I hope this was able to help someone out.

8 Comments

I was given a bike with both pedals snapped of, one of them had been drilled out and the thread destroyed, I went into the alley out back and grabbed a bike that had been left to rot, 60 seconds later, I'd switched the crankset, and was off!

wouldn't that be theft?

That is going to be what I do when it breaks again.
I worked as a bike mechanic for 7 years, I would have just ordered a new crank arm from the company and the new pedals, then reinstalled the lot. I would have also tried a rethreading tool, it is a special tap the manufacturers made so you can either tap the old threads lining them up, or make new, larger sized threads making it possible to jump up the next size of threads. Each requires some amount of special tools and a vise, drill. More bike shops than you know are able to do these repairs, and if you can find the bike mechanic at the store you bought it from, 9 out of 10 times they can order all parts for you for free under warranty clause.
The reason your crank arm threads were stripped is because it was cross-threaded to begin with. Department store bikes like you have there are usually assembled by amateurs at the store, and especially because of the reverse threading making things confusing, it can be easy to cross thread pedals. I always advise people to take department store bikes into a bike shop and pay them $30 or so to give it a once-over.
The cranks in the photos look to be steel, and if you were able to get enough bite on the threads to tighten them up, I think you made a good repair, and you'll get a lot more life out of the bike without spending any money.
If this were an adult bike, and with alloy crank arms, you would be looking for trouble.
Good instructable.
I think it was a quick put together, where we got it at.
Also if you position the crank so you insert the pedal from the "back" of the crank and tighten, you will effectively re-thread the damaged section. all that would be required is to pick the first threads out or straighten. Then remove the pedal from the back of the crank and install..... works on exercise bikes as well
Thank you for the tip, I will have to try that.