A new person looking for advice on a stuck Seatpost
 

Hi, new person here from Wakefield, Britain. Came here to look for help with my seat post on a steel globe roll 2 single speed, it's stuck fast I've tried WD40, a large bit of wood for leverage in seat post mechanism and hammer etc?
Can't get moving or adjust? :(
Any ideas? Would be grateful.

Welcome. Check threads in C&V.
Usually, for the uninitiated, the first rule is: do no harm. Not useful to get it unstuck by buggering the seat tube.

Best result is to remove chainset, open the bottom bracket, flip the bike and come at it from the inside with something much stronger than WD40's std product. Soaking overnight may help a stubborn problem with a struggle-less chemical solution.
I have heard of using a piece of cloth tied at the post/tube junction and soaked with your chosen chemical liquid, .......sometimes for days.
Beyond that = there are various mechanical methods. Not always preferred, but moving in the direction of 'no other solution'.
Can you do that? Tools?

I now see 5 posts listed, so you probably have your answer.

Greater than 15 million hits for "Stuck Seat Post Youtube"...

My last ditch trick is to alternate spraying the tube with Trifluoroethane and PB Blaster. A cheap source of Trifluoroethane or Difluoroethane is just getting a can of Liquid Air or Dust-Off used for blowing out dust from electrical parts. Just hold the can upside down and spray to freeze/chill the tube. There is also CRC Freeze Off but it does not get as cold.

use the frame to break the tube loose.

https://www.youtube.com/watch?v=SBXKU2QDY7c


https://www.youtube.com/watch?v=zTC4xh3UmwQ

Welcome to the forum

Thread moved from Introductions to General Cycling.

I agree with the advice about spraying/squirting/dripping things into the seat tube to soften the bond.

Another (later, after the chemicals) technique is to remove the saddle, flip the bike upside-down, and lock the seat post into a vise. Then use the frame as leverage to twist it free. Search for videos on youtube.

Try a 50:50 mixture of acetone and transmission fluid. PB blaster and Kryoil are good too. May take a few applications over a few days.

What are the frame and seat post made of? Round or aero shaped?

^ This.

Use a shot glass for quantity.

Let it sit for a week. Try to free it. If still stuck, give it another shot and let it sit for a week. Has worked for me every time.

I've had success with 2 methods. 1. Slide hammer use a dent pulling slide hammer attached to top of post with some chain, and whack it up. Use a pipe wrench to get a little twist every few blows. 2. Drastic situations requires drastic measures. Use lye. It's caustic, so be careful. It works.

Would a CO2 cartridge get cold enough?

Spraying CO2 could get the part down to temperature -60°C but a CO2 cartridge would not hold enough or spray long enough to do the job. There are a number of ways to get the temp down. For instance Dry Ice pack, R type refrigerants $$$, even highly flammable liquid hydrocarbons, but the cheapest and safest source I have found is the DutOff type air sprayer. Just hold the can upside down and spray to cool the entire head and stem. Then tap the stem with a hammer and see if it can break free a little. That will allow your PB-Blaster to get deeper into the joint and possibly loosen it. This method is a real winner when used on dissimilar metals. I only mention it here as it is not well described in the "Stuck Stem Youtube Aannals"...

PB Blaster is the best stuff I have used (I’m a former bike mechanic), though it is noxious stuff.

None of the things posted up to this point are worth much. WD40, PB Blaster are worthless. WD40 simply does not penetrate well, and the only good thing about pb blaster is it's name and the graphics on the can.

The best penetrating, rust and oxide dissolving product for this type of problem I know of is called Kroil. The last time I bought it was directly from the manufacturer and they sent me two pocket-sized cans of it, not spray but old-type metal cans with little caps. I used this to get a steel seat-post out of a steel lugged frame a couple years ago. I just put it around the joint of the two parts and it is amazing at creeping in by capillary action. I put it on, let it sit overnight, and tried moving the post. I did this about three days in a row and on the third day I was able to move the post a little so I put more on it and it got better, and after a few more days it came out with a little twisting and tapping.

It is too bad you put wd40 on there first because now that it has gone into the problem it might actually work to keep any better chemicals out or it will dilute them so it may take longer. But if you can get your hands on some Kroil it is well worth it, a little goes a long, long way, the cans will last you for years, and once you try it you will pick it up every time you work on anything that is oxidized or rusty. If you can not find kroil then you are better off using kerosene or gasoline than most current commercial products, I think in the UK you call them paraffin and petrol.

3000 attempts later

https://cimg3.ibsrv.net/gimg/bikefor...82d6e019cf.png

KROIL = good
 

[QUOTE=beng1;22554159]

The best penetrating, rust and oxide dissolving product for this type of problem I know of is called Kroil. The last time I bought it was directly from the manufacturer and they sent me two pocket-sized cans of it, not spray but old-type metal cans with little caps. I used this to get a steel seat-post out of a steel lugged frame a couple years ago. I just put it around the joint of the two parts and it is amazing at creeping in by capillary action. I put it on, let it sit overnight, and tried moving the post. I did this about three days in a row and on the third day I was able to move the post a little so I put more on it and it got better, and after a few more days it came out with a little twisting and tapping.

KROIL, in my experience, works well - just have to wait for it and make sure it really flows on to the stuck parts - above advice is good.

If Kroil does not work after about a week of trying...... pee on it once a day for about a week - gently tap the tube each day with rubber mallet and carefully twist it with a pipe wrench.

If still stuck - probably not going to get it out........

Spraying all sorts of oil or homebrew is a waste of time and money. No amount of spraying and waiting will unstick the post. - You need brute force or the slightly less ham fisted method, that is sawing off the top of the post, then halving the post lengthwise from the inside, with a hacksaw blade. It is time consuming, but unlike spraying stuff hoping for a miracle, it actually does something.

yup, had an aluminum seat post seized in a steel frame, same technique worked for me.

Penetrating fluids:


This test that measured penetration creeping depth as well as torque, showed that Kroil works but no better than much less expensive fluids, even WD-40 or acetone and ATF. PB Blaster and Liquid Wrench also worked fine compared to the control.

Part 2: More penetrating fluids that work.


DOT 3 Brake Fluid worked better than some specialty penetrating fluids, but not as well as Seafoam Deep Creep.

Takeaway: no need for snake oil, but if it's one of these, it will probably work about as well as someone's secret miracle formula.

Interestingly, seat posts get stuck due to an electrolytic reaction between the aluminum seat post and the steel tube. Solution = grease heavily between metal parts even if they don't move.

I ignored the do no harm after a couple of bike shops refused to touch my stuck seat post. I used a hack saw and diagonally sliced off the post then cut two slots down the length of the post that was stuck in the frame. I then drilled through the post and inserted a screwdriver to crank/rotate the post loose. Yes, it was a real sweat but was rewarded with the post coming out.

A few years back, I picked up a Kestrel carbon road bike that had a stuck seatpost at an estate sale. Was there to get different bikes and accessories and noticed that the Kestrel had a free stem but a stuck post. Parts alone were worth what I paid for the whole bike, so sure, why not take a chance.

Now this was a new one for me, how to free the post without damaging the carbon monocoque frame. Post was an American Classic alloy, and the frame had an aluminum sleeve within the carbon seat tube.

What finally worked: Attached an old saddle to the American Classic. Got a small can of Kroil for something like $12 USD. Dribbled Kroil around the post, let it sink in, took a rubber mallet to the side of the saddle and started giving some controlled whacks. Rinse & repeat. Took me a few weeks and who knows how many tries, but it finally gave without damaging a thing.

Supposedly Kroil has a micropenetrant chemical structure and works similarly to the 50/50 combo of ATF & acetone already mentioned. Thought I'd mention it in the spirit of whatever works. Still have that original can and have used it several times since.

A Specialized Globe Roll 2? That's only about a 10 or 12 year old bike isn't it?

I don't think it will have come with bottle mounts or mounts for a frame pump on it. So if any such are on the seat tube then they might have been added after the fact and might be one stuck right through the seat tube and into the seat post. Might need to drill out the rivnut or what ever was used first.

If it is only a dozen or so years old, I wouldn't think it'd have a seat post worth saving for the generations to come to marvel at. So if nothing else works for you, just take the saddle off, clamp that bike upside down by the seat post in a bench vice. Get the vice very tight and give a good twist of the frame with your hands and see if it breaks free.

But not so much that you put a permanent bend in the frame.

Failing that, if it is indeed a aluminum tube in a steel frame, then you can ask this member what his experience with Lye to dissolve the seatpost was like and whether the heat messed up the paint job or not. Apparently some have had good results with this.

https://www.bikeforums.net/bicycle-m...t-removal.html