Removing pedals from old MTB...

[classic33]

Yes, I put the 15mm spanner on the pedal and then used another spanner rather like in this picture to "squeeze" the 15mm spanner against the crank arm to attempt to turn it anticlockwise. Then the 15mm snapped.
View attachment 692930

What way round are you using the spanner? Assuming it's not a "straight" spanner.

 

[Ajax Bay]

It might...if you have a length of pipe thay will fit over it to give more leverage that would help.
Hitting it with a hammer might help, but it won't do the spanner much good.

A cone spanner will NOT do; not even a 'might'.
Put a chunk of wood under the bottom bracket (this stops any 'shock' force being dissipated by the pneumatic tyres).
Point the (either) crank forward (eg at 2:30 o'clock for the right side).
With a decent heavy spanner (see Ian's advice but an adjustable might do) point the spanner to the rear. Apply force to spanner, downwards, with pipe extension or, for shock, a coal hammer.
Unscrew

 

[presta]

Whatever spanner, lever bar, penetrating oil you use…….you also need a way to secure cranks from moving - so that all your effort is going into undoing the pedal as it’s clearly quite tight 👍

Bind the other crank to the chainstay with a webbing strap.

 

[TheDoctor]

Failing that, the bike shop can apply a very special blend of leverage and extreme violence.
Probably best not to hang around and watch...

 

[Mazz]

What way round are you using the spanner? Assuming it's not a "straight" spanner.

Sorry, Don't understand this question.

 

[Mazz]

Failing that, the bike shop can apply a very special blend of leverage and extreme violence.

Unfortunately my local bike shop is now a local bed shop. Guess there weren't enough footfall to keep it going. Sad really.

 

[Mazz]

A cone spanner will NOT do; not even a 'might'.
Put a chunk of wood under the bottom bracket (this stops any 'shock' force being dissipated by the pneumatic tyres).
Point the (either) crank forward (eg at 2:30 o'clock for the right side).
With a decent heavy spanner (see Ian's advice but an adjustable might do) point the spanner to the rear. Apply force to spanner, downwards, with pipe extension or, for shock, a coal hammer.
Unscrew

Thanks I will give this a go. Presumably any big fukoff mallet will do in lieu of a coal hammer.

 

[classic33]

Sorry, Don't understand this question.

Most decent spanners have an offset open end. One edge/side of the spanner will be longer than the other, that should sit on the top, where the force will come from. Less chance of it slipping.

 

[Mazz]

Most decent spanners have an offset open end. One edge/side of the spanner will be longer than the other, that should sit on the top, where the force will come from. Less chance of it slipping.

Thanks for the explanation. No, this was a bogstandard straight spanner and a cheaply made one ,judging by the snap.

 

[Mazz]

Sometimes you can get lucky with the angles and use a car scissor jack between crank and spanner

Interesting idea. I can't quite picture how you'd position the scissor jack but there must be a YouTube video about it so I'll search.

Edit: I can picture it in my mind's eye... you'd place the spanner and crank inside the "diamond" shape of the jack , then turn the handle to force the spanner anticlockwise.

 

[classic33]

Thanks for the explanation. No, this was a bogstandard straight spanner and a cheaply made one ,judging by the snap.

Where did the spanner actually break?

 

[Mazz]

Where did the spanner actually break?

You can see it ont floor in my OP.

 

[ColinJ]

You could try something like this, but heed the warning!!

Aargh - 3 years later and I now have the dreaded stuck double-sided SPD pedal problem!

Curse, sulk, pace about, scream, and then finally I had a bright idea...

*** READ THE HEALTH & SAFETY WARNING BEFORE TRYING THIS TECHNIQUE!!!! ***

As you can see, the cranks are off the bike.

I put one foot in an SPD shoe and clipped it into the pedal. I placed the pedal on a pile of timber, arranged in such a way that the crank would try to dig into the floor when I applied force to the pedal spanner.

Here is a photo of the setup for the left crank. On a hard tiled floor. A hard tiled floor that you would not want to fall onto...

View attachment 657501

I stood on the pedal and pushed down hard on the spanner. Success!

Now for the right pedal/crank...

I couldn't get the spanner at a decent angle when the pedal was balanced on the pile of timber like that, so I turned the stack so it stood on its edge. That gave me a higher platform to stand on. Or should I say balance on...?

I applied force to the pedal spanner. No joy. More force. Still no joy. I turned the power up to COME-ON-YOU-B*ST*RD!!! level and... there was a loud CRACK as the pedal came loose, I lunged forwards, the pile of wood toppled sideways and I fell across my kitchen taking a pile of tools and bike parts with me. I whacked my hip really hard on the floor and narrowly missed faceplanting on the wall!

I lay there shocked for a couple of seconds before saying a little prayer to the God of Hips... PLEASE let mine be intact!

A quick body check... Phew, got away with it!

Somehow I have not broken myself, my bike, or anything in the kitchen.

The technique did work, but if you decide to use it make sure that you don't balance on a precarious platform. Ideally, one person does the standing on the pedal and someone else turns the spanner!

 

[Reynard]

That looks well rusted.

I know the OP said they've used WD40, but from my experience, you sometimes will need to marinade for up to a week before stuff will shift. Placing the bike on its side to allow the oil to penetrate the threads properly, and give it a few good smacks with a mallet to try and break the bond between pedal and crank.

Sometimes patience gives you a better pay-off than brute force.

 

[fritz katzenjammer]

I had to get the pedals off of a 45 year old Bridgestone last year. No amount of brute force, big ass wrenches or bigger mallets would stir them.

A friend advised me to heat the crank arm around the pedal area with a propane torch and then drop it in a bucket of cold water... three times... the silly thing came apart very easily after that. The shock breaks down the oxidation apparently.