Ammonia?

[IBarrett]

If you're not worried about the paintwork a blowtorch is your friend.
Ask around, you might be surprised who has one.

Mapp gas is even better but keep it moving and try to heat up evenly.
Wear rigger gloves so you don't accidentally get hold of anything hot by mistake.

I take it you've tried drowning it in penetrating oil. Not WD40 but the proper stuff.

 

[Daddybus]

@classic33 err...no? From below? With a spare stem????
@IBarrett I'll ask my dad if he has one... I drained the coke 'cos I've had to put it back in the shed (before the wife gets back & wants to use the sink! ...) I've filled the tube with 3in1 (bit thicker so slightly less 'leaky')
Previous to today's shenanigans wd40 & 3in1 were my weapons of choice (read the only things I had at hand)

 

[classic33]

@classic33 err...no? From below? With a spare stem????
@IBarrett I'll ask my dad if he has one... I drained the coke 'cos I've had to put it back in the shed (before the wife gets back & wants to use the sink! ...) I've filled the tube with 3in1 (bit thicker so slightly less 'leaky')
Previous to today's shenanigans wd40 & 3in1 were my weapons of choice (read the only things I had at hand)

Have you tried hitting the stem back into the steerer tube*, is what was meant. Sorry.
*With the forks on the floor, or an old wheel in place.

If you're going down the cola route, use the cheaper stuff.

 

[Daddybus]

Have you tried hitting the stem back into the steerer tube*, is what was meant. Sorry.
*With the forks on the floor, or an old wheel in place.

If you're going down the cola route, use the cheaper stuff.

I whacked it hard several times.. I marked a line on the stem ....it didn't move a mil

 

[Daddybus]

Yaaaaaaas!!!!!

 

[mikeymustard]

So...? What shifted it in the end?

 

[Daddybus]

Ingredients,
1 black & decker workmate
1 3' length of 2" x 2" softwood
1 heat gun
1 can wd40
1 watering can of cold water
1 77 yr old dad with hands like shovels

Method (stem)
Heat the head tube, spray with WD 40, cool the stem with water, repeat many times
Clamping the fork crown in the workmate really helped to keep it all rigid while twisting the handlebars using the length of wood threaded through the drops diagonally as a lever ...still took around 2hours tho!

Method (seat pin)

Clamped the top tube in the workmate so the bike was lying down flat, heat WD & cool as before then twisted the pin with mole grips (I didn't want to keep it so didn't care if it got damaged) took 15mins ish?

The workmate was the key I think.. you just can't apply enough force without it, it stops the forks twisting & with its wooden jaws there's no damage...

 

[mikeymustard]

Great British Bike Off. Geddit?
Well bloody well sod you [to quote Alexei Sayle]

 

[Daddybus]

Haha... Great idea for a programme -great british bike off with Alexei Sayle- (on Dave of course!)

 

[mikeymustard]

I'm sure Alexei would be up for a prog about bikes, he is a PUFFIN after all!

View: https://www.youtube.com/watch?v=vW60b7TXr2s

 

[Illaveago]

It is nice to see the Sun Yellow Jersey is coming on!

 

[ChrisEyles]

I like the solution of clamping the forks in the work bench, nice one I had to give up on freeing a stuck stem on a Sun Solo last year, and felt thoroughly disappointed in myself! If it hadn't gone on to a new home I would be having another crack at that sucker this evening... well, I'll remember for next time.

 

[Daddybus]

This is the first bike I've restored with all alloy gubbins -what a revelation soooo much better than that chrome sh*t no rust no pitting easy peasy

shiny squeezy

 

[Illaveago]

This is the first bike I've restored with all alloy gubbins -what a revelation soooo much better than that chrome sh*t no rust no pitting easy peasy View attachment 120788 shiny squeezy

Those will polish up nicely with some Meguiars metal polish, that is if you want them to look like chrome.

 

[Daddybus]

I just used a bit of brasso that I found under the sink on 'em... Maybe I'll take a look at McGuire's