Good grief. I suppose it was bound to happen. I can not even BUDGE these pedals loose on this '86 Trek 760. No doubt there will be greater measures of force applied in hopes of cracking loose this crazy tight set of pedals. Did a shop monkey muscle these up thinking it could save a riders life?? I never go beyond "snug" on ANY of my bikes, EVER.

I had this happen recently on my Guerciotti and the Look pedals that were installed. I had to take it to the LBS after a whole evening of attempts.

Some combination of Kroil and/or warmth might do the trick. A hefty wrench and a whack with a big hammer might break them free. Could well be caused by a lack of grease on threads and not initial over-tightening.

At least it's not a seatpost. Keep pushing.

Judicious application of heat should work. Aluminum (crankarms) has a higher coefficient of thermal expansion than steel (pedal spindles).

Oh, and make sure you are turning in the right direction!

I was telling myself that very thing.

This could happen as a result of insufficient tightening. Something about the gap allowing the metals to fuse chemically.

Use more leverage and make sure you're turning in the right direction. You'll get them out. I've never used heat.

It is that "judicious" word that makes me nervous.

Lately I've been using a "Serpentine belt tool set" used for compressing the spring loaded pulleys on a car so the serpentine belts can be changed.

Comes with a set of crowfoot wrenches (the 15mm is used on pedals), and a long flat handle that's almost 23" long. Fits on the flats on most pedals and has a longer handle (and more mechanical advantage) than any pedal wrench. They are often on sale at Harbor Freight for $12-$13, and the bonus is that you can use it to change the belts on your car too.

Position the crankarm to the bike's rear of the crank center, place a 9" cinderblock under the crankarm, and place a piece of a 2 X 4 on top of the cinder block (this setup prevents torque from being applied to the crankshaft). Place the crowfoot wrench on the pedal flat, and wrench away.

No stuck crank has resisted this setup yet.

I always had luck breaking tight pedals loose from crankarms by doing a scissors approach ethics the crank arm and the wrench on the pedal and applying a death grip with my hands to pull the two together. It also avoids putting any uneccessary straining the chain and the rest of the drivetrain.......
Just watch it so you don't get any fingers pinched in the process......

A little penetrating oil never hurts. I usually have good luck tapping the end of my 15mm wrench w/ a rubber mallet.

I spread my 15mm Snap-on open end wrench doing that - but heat has worked everytime for me.

Me ether too!

Although I 've heard of using heat I've never needed it. A little rust buster or penetrating oil. The bicycle properly held in the bicycle stand. And firm confident pressure (and maybe a hammer tap).

But... how do you guys that use heat... apply it? Hair drier, propane torch, halogen light, electric blanket?

A Park pro pedal wrench and a 6' piece of old roll bar tubing has never failed me

It's a propane torch for me. (Judiciously applied!)

If I am ever completely stuck.... I'll try it. Worse that could happen is I remove the crank.... and replace it.

A heat blower used for shrinking model airplane covering works.

I have a serious heat *** (hair dryer on steroids).

Hmmm, maybe I could spell it 'heatgun', let's see... Why, yes, that works. How silly.

When stuck, I find taking the crank off, sticking it horizontally in a bench vise, wrapped in a rag of course, allows better leverage with whatever tool you use. On the drive side, just invert with the pedal facing the floor.

The approximately 4' handle of my hydraulic floor jack conveniently slips over a 15mm wrench perfectly. I've only had to resort to this once, but it worked like a charm.

Penetrating oil, and the pipe extension on a quality pedal wrench mentioned above. I also use a hunk of 2X4 I've covered in old sleeping mat as a way to keep the cranks from turning (wedge it between he crank and the seat tube). Never failed me, never ruined anything, never even broke much of a sweat (I have a long cheater pipe -- part of a metal railing from an industrial drill rig I rebuilt back when I still worked a real job).

As Archimedes said, "Give me a lever long enough, and a good wrench, and I will break that pedal free" -- or something like that.

use penetrating oil and stand on your long pedal wrench.

x 100

Just a friendly reminder if you plan on using heat... penetrating oils are flammable! It flashes off pretty quick but the small fireball can be a bit of a shock if you aren't expecting it.

+1 this. Use soft jaws to avoid marring the crank. Slip a pipe over the wrench to extend the lever arm if needed.