Stuck/fused pedals. What’s the solution?

[Woz]

Some good input there.

Collapsing threads would be a last option for me; where I would go slow and gradually increase the drill size; starting from the back of the crank side and no need to cut the entire axle off.

Interesting tool that stud remover. A bit unsure how it can work since a lot of pedals have a conical spindle.

 

[The History Man]

Looks like a possible option if fire and brimstone fails.

 

[Woz]

Another note; the majority of stuck pedals have been on neglected lower - mid end bikes with nasty original steel / plastic cage pedals (VP / Wellgo etc.) that were put on the bike with very little grease to begin with. Also had a surprise case of wrong pedals being forced in the wrong cranks (ie. Left pedal in Right crank).

 

[sickpup]

There are a few ways of doing it with welders.
You can heat the axle from the reverse side with a TIG welder, just have to be careful to not melt the crank arm. No filler needed, just use it for heat.
You could also cut off the axle close to the crank and MIG weld a large nut to it, the heat from doing this should crack the bond between axle and crank and with the large nut you would be able to get a socket and breaker bar on it.

The picture attached is a nut I had to MIG weld to a seized and broken bolt last week. That took about 160amps which is a huge amount of heat to put into a 6mm bolt but it works really well, just give it a chance to cool before you try to remove, huge amounts of expansion, so much the 10mm spanner didn't fit until the nut cooled back down.

 

[hookooekoo]

Another option would be to grip the pedal spindle in a large metalworking vise that is securely attached to a bench, and then heave on the crank. This one has 4.5" jaws, so it's slightly smaller than mine, which has 6" jaws. Note the weight, it's 15.3kg!

https://www.ebay.co.uk/itm/174840120937
They want £150 for it. But I got mine from a house clearance place for about £15 a long time ago. You have to be a bit careful buying second hand vises, because some may have cracked due to abuse. Be wary of those with a thick, fresh coat of paint.

The vise option is expensive if you only want to do one job, but it's a good investment if you do a lot of stuff yourself. I've used mine for so many things over the years. Mine is so huge and it opens so wide that I even used it to replace the sealed bearings in a pair of Hope hubs.

 

[hookooekoo]

Interesting tool that stud remover. A bit unsure how it can work since a lot of pedals have a conical spindle.

I suppose it all depends on what the OP has. A lot of the pedal spindles I've seen had a constant diameter between the inner and outer races.

 

[The History Man]

The nice sealey cam thing doesn’t unstick anything though. Already moved workbench and vice. It’s the stuckness I need to solve not the leverage.

 

[legrandefromage]

my method as I am both a scrimper and saver as well as being too skint or mean to buy the correct tools is:

Patience

Oil of any kind

leave to soak

Patience

a long bar around the crank

a not so long bar around the pedal spanner

weight on the pedal by standing on it, the long bar on the crank arm stops it from moving too much

sometimes its better to leave the cranks on the frame for more leverage

usually a short sharp shock and theres a loud squeak or crack as things start to move

or the pedal rounds off

or the pedal spanner pings off and hits you square in the forehead

I've got some cranks that have been stewing for months which I'll attack over winter

and scars.

 

[hookooekoo]

The nice sealey cam thing doesn’t unstick anything though. Already moved workbench and vice. It’s the stuckness I need to solve not the leverage.

The nice sealey cam thing is to overcome this problem:

15mm pedal wrenches spin on hexagonal shaft.

But if you have a quality metalworking vise you might not need the nice sealey cam thing.

If it's still too tight, then you might need to heat the crank arm. Aluminium expands at a greater rate than steel, so heating the crank arm should help loosen the threads and break any corrosion that is present.

* When heated, the expansion rate of aluminium typically exceeds that of steel by a factor of about 2:1. The differential is even greater for titanium.

 

[hookooekoo]

Expansion rates/coefficients of common metals.

https://amesweb.info/Materials/Linear-Thermal-Expansion-Coefficient-Metals.aspx