I have following problem:

I am trying to remove a bicycle pedal from the crank arm. It is completely stuck. I tried to prolong my wrench with 1 m pipe to have bigger lever. It didn't help. So I am trying now to find something that can penetrate in the thread between pedal and crank arm and release it. Google offers: WD40, gasplus, coke, various home mixes form veg oil and acetone (From my own experience: Don't do that. Once when I was about 10 y.o. I have very thoroughly oiled the sawing machine from my mom with veg oil. Some of you know what happened after two days. . It got incredibly stuck because veg oil solidified and worked like a glue.).

Anyone here ever had a similar problem? Any ideas for penetrating oil? And no, lubricant for sex won't do the job here.

How random, I had this exact same problem over the weekend trying to get a saddle off of an old bike. WD-40 didn't work for me, so if you find a solution I'd be interested!

Kroil is a good brand of penetrating oil. For homemade, use equal parts ATF & Acetone.

Yes. I was turning the wrench the wrong way.
Is it the right pedal that has left hand threads?

^^^^
Check that first although iirc it's the left pedal that has the thread reversed.

Also, heating the joint might help. I doubt that a lubricant will be much use if 1m of leverage didn't help.

To loosen a pedal you turn the wrench opposite of the wheel's direction (when going forward). So to loosen the right pedal, you turn the wrench left.

Direction has been checked. I tried it the correct way.

With heating..... I have read also somewhere in google, but it seems so counterlogical to me. Heated metal is going to expand. So I would expect it to be stuck even more. Or do I miss something here?

Going to try to soak it for a day in nail polish remover (have this at home). And if that won't help, then this kroil and co. stuff.

I mean at the end if I have to destroy the thread to remove it, so be it. But then I would have to replace the crank. And that one is also sitting at the same place for 10+ years.

The trick is to heat the thread on the crank arm just enough that it expands while the thread on the pedal doesn't.

Try putting the wrench in place and banging it in the right direction with a hammer.

My motto is never give up except on a thread that's seized up.

I thought you already noticed that I am slightly obsessive. That is not only with M05.

I mean.... There is just no way that I won't get it out. It is totally possible that I am gonna to destroy it in the process, but then I would be in no worse position than now.

I did it i did it i did it!



What worked was the heating. Honestly, I have no idea why and how. But I just took a candle and held it under this joint between crank and pedale for few minutes. And then it just worked with a little leverage.

thank you thank you thank you guys!

judging by the picture and the fact the bike has been in the same spot for 10 years. Id just advise you to buy a new bike, I cant imagine that bike is worth replacing all the bearings, chain, and tires

Eastern Bloc tho.

It is one of 4 of my bikes. I am just looking if I can get it going because I have a bigger company here in September.

And it has not been at the same spot. I just hadn't replaced any parts for 10 years. So the crank on the bike has not been replaced. And yeahhhh ... it was a lot outside

edit: And why the heck buy something new, if I can repair what I have? Tires on it are 3 month old. I don't think that I will have to replace anything other than pedals.

Ha! Had the same problem on a 20y old bike - Applying WD40 multiple times and letting it sink in for hours did the trick (plus brute force). Also note that pedal threads screw the other way round

+1 for repairing old bikes instead of buying new (crappy?) ones, especially in cities were there is lot of bike theft, which is the case in most of the larger cities in Germany

Yeahhhh it is eastern block mentality. And I think it is actually a pretty good mentality compared with being trapped in a cycle of buying and throwing away stuff. I want to stay this way.

ahh, my bad.

There are a few factors at work. Different metals expand at different rates when being heated which can break the bond. Generally when heating the parts the outer part heats up faster causing it to expand faster than the inner part. Even if both parts are the same metal and heat up at the same rate the act of expanding and contracting can break the bond.

Tx. I think I understand now. I was thinking like in the picture that the metal of the crank and of the pedal is going to expand in all directions so that the hole in a crank will be smaller and pedal part in it thicker. But the trick is that different rates expansion and later contraction brakes the connection between pedal and the crank.



A funny story to this from my university time to the expansion of the metal. I was doing experiments with an ultra cold (-269 C°) in super vacuum microscope that had to be super stable against every vibration. So the thing was three meter in the earth and all manipulations were made through a long pipe with super fitted to the diameter of the pipe handler like the pedal in the crank only much more fitted and without a thread.

And then we got a new post doc. The dude was instructed that he mustn't let the system get to the room temperature. He has to ensure that it is cooled every time with fluid helium. And what is he doing.... He allows the system get to the room temperature. This handler was through the expansion completely glued to the pipe. It all become basically one. Pouring amounts of fluid helium on it didn't help, trying to pull it out with a motor didn't work, nothing worked. The floor in the building had to be destroyed and the whole system had to be dug out. Costs approximately 1 million.

haha, what happened to the post doc?

He stayed to the end of the contract but didn't get a continuation. There were other problems with him. Dude was japanese and he just couldn't bring himself to ask people to repeat, when he didn't understand something. This incident was basically a result of completely failed communication.

I recently had a ton of trouble getting a bike pedal off, figured it was fused and gave up. Did not realize that the pedals did not both unscrew counter-clockwise. I think I tried so hard to get the pedal off that now it's really stuck.

when I worked in a bike shop we would get people who would come in because their pedal was seized, but really its cuz they just were turning it the wrong way.

you worked in a bike shop O_O
So you should know a bunch of good tricks.


I remember the direction to open it is against where the bike goes forward for both pedals.