You are reading a single comment by @Jaaamie and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
@Jaaamie
Just thought I would jot down my jumble of thoughts about my recent adventures with a seized stem. Tried penetrating fluids and heating the shit out of it, all to no avail. After reading the comments on the page before and watching RJ the bike Guy's videos I eventually came to sodium hydroxide. First point - 'Soda Crystals' are not sodium hydroxide. I wasted half a day waiting for them to do something.
You want caustic soda. I got this from Robert Dyas for £2.29. So I couldn't find anyone detailing how much caustic soda they were mixing with water so I (In hindsight this was stupid) first tried 100g mixed with water. Make sure to add caustic soda to the water and not the other way around. I want to preface by saying that if you add 100g to ~500ml water it will get lairy. Particularly if it is hot water - I used as hot as water as I could get from the kitchen tap. Be careful and cover your arms and legs. Sloooooooowly add the caustic soda. I used an old protein shaker and just propped the fork in upside down against a wall outside. When I started with the full stem it would bubble like crazy and give off a load of fumes. This is good because you know it's working but be careful of the fumes as they're rank. I refilled with fresh water + 100g caustic soda every 8 hoursish off and on over a few days. I think I got through 600g in the end (I have a leftover 400g if anyone wants to come grab some S9).
By the end there was just a small slither left in the steerer. For the final mix I put the fork in the water before adding the caustic soda and then poured a fair bit down the bottom of the steerer to ensure I was maximising the amount of action going on around the slither.
Any questions about the process give me a shout. I would definitely just go straight for this technique before even bothering with penetrating oils etc. Quill stems are cheap anyway.