Bicycle Mechanics - pedals rusted into crank

I'm trying to get some pedals out of alloy cranks. I live in a hot humid seaside island, so rust is endemic and fierce.

I spent 10 minutes whacking a spanner with a hammer without budging them, till I snapped the jaw on the spanner.

I've tried spraying with WD40, to no obvious effect.

Any suggestions? I don't live in the US and our hardware and bike shops don't carry
the exotic anti-rust concoctions I see advertised on various webpages.

Could heat help or make it worse?

For all the yanks, "spanner" is the Queens English version of "Wrench" and if you snap one its because you shouldnt hit it like that. Take a length of pipe and use it to extend the handle so you have more leverage.

My way of removing pedals is to put the bike in lowest gear, point the crank forward and up, to point the spanner handle rear and up. (This takes care of the reverse thread on LHS) Apply brakes and gently apply force to the spanner. IWith an extension pipe, hand pressure should be sufficient but without one I usually use foot pressure.
WD40 takes some time to penetrate, maybe a couple of days.
When you reapply the pedal, smear grease over the threads.

WD is not really a penetrant. PB Blaster is the way to go.

WD is not really a penetrant. PB Blaster is the way to go.

+1.

WD40 is better than nothing. Liquid wrench does a better job than WD40. I've never used PB Blaster but I assume it's designed for removing rusted fasteners and will do a better job than WD40 too.

PB blast it (outside).

If that still doesn't work for some odd reason, remove the crank arm and soak the pedal area it in ammonia.

At least you don't have to worry about some one stealing them

Let me guess... it's the left pedal that's stuck.

Let me guess... it's the left pedal that's stuck.
+1, You beat me too it. Has the OP taken pedals off before? Don't mean to be insulting at all, just wonder if the OP knows the left threads are reversed.

Remove the crank arm with the stuck pedal and soak the pedal and crank arm end in automatic transmission fluid. If you don't want to remove the crank arm from the BB simply hang the bike up from the rafters, remove the wheels, and let the bike down so the pedal and crank arm it's stuck in is allowed to soak in a can of transmission fluid. One of my hobbies involves restoring antique engines and I use transmission fluid pored down the spark plug holes to loosen stuck pistons in the cylinders. It works better than penetrating fluid when trying to separate aluminum and steel parts. One word of warning you should know about doing this. The transmission fluid will eat away most aluminum not specially treated to prevent that from happening. Don't soak the parts too long or your aluminum parts will develop pitting and ruin the finish.

+1, You beat me too it. Has the OP taken pedals off before? Don't mean to be insulting at all, just wonder if the OP knows the left threads are reversed.
Yes, he has taken pedals off before, and he does know the lhs has left hand threads. Actually, it's the rhs I'm working on now, though I expect the other will be equally stuck.

PB blast it (outside).

If that still doesn't work for some odd reason, remove the crank arm and soak the pedal area it in ammonia.

As I mentioned, things like "PB Blast" and "Liquid Wrench" don't seem to be available here. But I liberally applied WD40 and will attack it again, using a pipe extender in a few days.

I haven't heard of using ammonia -- does it act as a penetrating lubricant, or does it have a chemical effect?

If you have an aluminum seatpost stuck in a steel frame, a common solution is to pour in ammonia from the bottom bracket. I was thinking that you may be able to get the same results with your steel pedal spindle in the aluminum cranks.

For all the yanks, "spanner" is the Queens English version of "Wrench" and if you snap one its because you shouldnt hit it like that. Take a length of pipe and use it to extend the handle so you have more leverage.

I've actually referred to some tools as a "spanner wrench" before. Am I just double stating the item?

Anyway, how about naval jelly or something to loosen the rust? And considering where you live, you might want to remove and lube all threaded parts every year.

This is why I always wrap some teflon tape around my pedal-threads before installing... Shops like to use grease because it's quick and easy...

Anyway, how about naval jelly or something to loosen the rust? And considering where you live, you might want to remove and lube all threaded parts every year.

Naval Jelly is yet another thing I've never seen here. Maybe I should try some marine supply shops. This is a very throw-away rather than repair society.

And I do lube stuff preventatively, but the problem is when I'm salvaging neglected bikes or fixing them for friends, often after years of neglect.

This is why I always wrap some teflon tape around my pedal-threads before installing... Shops like to use grease because it's quick and easy...

And there's also absolutely nothing wrong with using grease. Next.

What about using some heat on the crankarm, along with tapping the end of the pedal with a hammer to try and break the bond that way? I've found working on old cars that sometimes the use of a propane torch and a few "wacks' to vibrate the part loose gets things moving nicely. Apply the heat to the end of the crank and work around the spindle hole. That way the hole will expand, helping break the bond. Just don't go overboard and do the 'red hot' thing... not good.

Steve W
Who keeps his stuff lubed and corrosion free, but has often cursed the sins of others.....

And there's also absolutely nothing wrong with using grease. Next.

Teflon works better than conventional grease when dissimilar metals are threaded together. Grease might help in assembly, teflon helps in the dissasembly.

another tip I've found useful, put the chain on the big ring before applying lots of force. ramming your hand into a chainring after the pedal finally gives way sucks bad. ask me how I know.

And there's also absolutely nothing wrong with using grease. Next.


Wow. I use grease, but there is a major problem with it: it's messy and gets your clothes filthy. Personally, I thought teflon tape was a novel and good suggestion. You missed your stop off the rude bus.

OP, I had one of these and couldn't get it removed with my very nice ELDI pedal wrench. After two days of consistent application of PBlaster eventually did it. I realize you said you can't find that stuff: auto parts stores are the best. If not that, then Liquid Wrench or other lube works. I think that WD40 will work as long as you apply it consistently over several days, and then use a properly leveraged tool: a long-handled pedal wrench, or a wrench supported by a pipe. Friends always help with these things, too. If it doesn't come at first, work on 'eroding' the bond slowly over several days, i.e. just apply some pressure each time you add the WD40 or other lube.

Oh, and a torch could probably help: the aluminum will expand a bit after heating.

I have removed many a stuck pedal using various solvents and cheater bars on the pedal wrench. One method not mentioned is boiling water. A customer had some ATAC's stuck in his Campy cranks. Try as we might we could not get the pedal to budge. The older ATAC's use only a allen wrench so this made it even more of a pain in the butt. One kettle full of boiling water on the crank/spindle and it came right out. you may want to run a crank tap thru it after you get the pedal out to clean it out. +1 on grease. If you cant keep grease off your clothes when working on your bike perhaps some overalls would be a worthwhile purchase for you.

If you haven't already, try removing the crank arms from the bike. That way you can work at them on a bench or on the floor to get more efficient leverage on them. Also removing the rings from the crank will make things a bit easier too and reduce the chance of launching knuckles onto sharp teeth. As a previous poster mentioned, long pipes on the spanner and crank arm will give you a lot more leverage. Wrap the crank with a rag to prevent damage from the pipe.