Friend of mine wants to adjust their saddle, but the seat post is rather stuck. They’ve already tried soaking in lots of WD40.
I’ve put the frame in a vice and tried twisting with a set of Stilsons and a scaffold pole but the seat post is just getting chewed up (it’s aluminium)
I also tried applying a little heat, twisting and giving a belt with a hammer and a bit of wood, but nothing’s shifting.
Any ideas?
@hernehillier is the bike master!
Maybe heat was the wrong approach if aluminium expands more than steel. Would discharging a CO2 fire extinguisher over the joint help?
Regular WD-40 is a swiss knife type of oil - and is pretty bad at all things it does except actual water displacement and being a spray. It is only a temporary lubricant and has below average wetting/penetrating ability. Get something that has “penetrating oil” written on a can. I personally use plusgas.
@asander1 Cheers!
@RichM If you’re around tonight I’d be happy to help out. Heat, cold and percussive shock have never failed me in removing stubborn posts, although they can take days sometimes, and you’d need to remove the bottom bracket bearings.
The above point about penetrating oil is important. If your mate isn’t fussed about the stickers, here’s what I’d do:
-Procure some wd40 specialist penetrating oil.
-Use a heatgun to warm the seat tube, taking care it’s not too hot to touch.
-Apply generous amounts of penetrating liquid where the post meets the frame.
-Let sit for 30 mins, and apply more liquid.
-Let sit for 2 hours, and try removing the seatpost with a sacrificial saddle in the rails.
-If it doesn’t budge, whack the saddle with a rubber mallet firmly but not hard, towards the bottom bracket. Try moving seatpost again.
-If it still doesn’t budge, you’ll need to get some degreaser, ice, water, duct tape, and a container.
-Degrease the seat tube as best as possible. Seal the end of the seatpost with the duct tape.
-Having removed the BB, invert the frame, and pour ice/ice water into the seat tube. Set over a bucket in case of drips. Let sit for 30 mins.
-Pour out the water, use a heatgun on high on the seattube. Apply torque as soon as possible.
Depending on how badly stuck the post is, you may have to repeat cold-hot several times. If it’s really bad, the head might become loose on the seatpost, at which point you’d be best off writing the post off, and having made 100% sure that the frame is steel, using caustic soda to dissolve the post. This will likely take several applications over several days.
Thank you! We’ll give that all a go!
Good luck!
How did you fare?
