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-   -   Stuck Seatpost. I need HELP! (https://www.bikeforums.net/showthread.php?t=593568)

metalchef87 10-12-09 09:43 AM

Stuck Seatpost. I need HELP!
 
I just got an 89 Nishiki Custom Sport and it fits me perfectly, except for the fact that I can not move the seatpost. It is rusted shut and no matter what I do it will not budge. Before you give me your advice, I will tell you what I have tried, with no avail.

I have tried to lube it
I have tried prying the hole apart just enough to loosen it
I have tried hammering it with a hammer :innocent:
I have tried to slip a razor/knife in between the post and bike to remove rust
I have twisted and lifted and pushed and pulled every which way but the stupid thing won't budge...

Alright I know someone out there has to have a solution...please share....please

USAZorro 10-12-09 09:49 AM

Try searching threads with stuck seatpost. We've gone over this scenario about a half dozen times in the past 3 years.

miamijim 10-12-09 09:53 AM


Originally Posted by USAZorro (Post 9842877)
Try searching threads with stuck seatpost. We've gone over this scenario about a half dozen times in the past 3 years.

Thats it?

old and new 10-12-09 10:26 AM

The subject has been covered way more times than suggested. one fellow just the other day, was only able to remove his after over a year trying on and off, I guess he finally had his lucky day. He'd not found the special solution either.

Sheldon Brown writes about this and I'd tried in the past before having read it. At the time, I'd made the choice to sacfrice the saddle by wrecking it. The saddle that was on the bike was pretty good, since then I've used cheap ones. Wrestling the post out using the saddle as a handle. What better to to use as a wrench. A saddle grabs the post entirely. If it's a modern post, the saddle will be sufficiantly flexable overal for added pressure (dif. to articulate) like a torque lever along with leverage. If it's an old type bare-tube post with the saddle clamp clamped to it, I can't think of a better task specific tool either.

Try a special Liquid Wrench type product PB Blaster is the best that I've come across, parts stores have it. Let it sit some. If nothing helps, last resort is to drip some Coka Cola down in there, an old exh. man. stud. rem. trick.

Old Fat Guy 10-12-09 10:53 AM


Originally Posted by old and new (Post 9843110)

Try a special Liquid Wrench type product PB Blaster is the best that I've come across, parts stores have it. Let it sit some. If nothing helps, last resort is to drip some Coka Cola down in there, an old exh. man. stud. rem. trick.

Modern Coca Cola does not work. You are dating yourself :)

Try ammonia if PB Blaster fails after a few days.

If it moves a mm, it will move a mile.

rccardr 10-12-09 11:19 AM

Step 1: Liberal PB Blaster applied each day for several days
Step 2: Very Very VERY hot hair dryer directed at outside portion of seat tube for 10-15 minutes. You want that baby to be too hot to touch, but not hot enough to damage paint or decals in the area.
Step 3: Can of Freeze-It or similar product. This stuff is sold in aerosol cans and used by janitors to remove gum and wax from linoleum floors and it will freeze the c#ap out of anything toward which you direct the spray tube (including your fingers or face, so be careful). Got my last case on eBay. Use it to freeze the seat post.

Hot tube (expands), cold post (contracts), PB Blaster (does that PBB Magic Thing) - works every time.

divineAndbright 10-12-09 11:21 AM


Originally Posted by Old Fat Guy (Post 9843286)

If it moves a mm, it will move a mile.

heh, I had the strange one a few years ago, I got to a point where I could spin it around 360 degrees, but I could still /not/ get it out for some reason, well until I got all rambo on it with a sledge hammer. Out of the four or so total stuck seat posts cases ive had so far only one managed to defeat me.

old and new 10-12-09 11:23 AM

I like what Old Fat Guy & rccardr just suggested. I've taken it under advisement and commited it to memory. THANKS

Old Fat Guy 10-12-09 11:27 AM


Originally Posted by divineAndbright (Post 9843510)
heh, I had the strange one a few years ago, I got to a point where I could spin it around 360 degrees, but I could still /not/ get it out for some reason, well until I got all rambo on it with a sledge hammer. Out of the four or so total stuck seat posts cases ive had so far only one managed to defeat me.

I've had the same scenario, spin, but not much movement in or out. It did eventually come out, and I firmly believe that if you can move it a little, eventually you can move it a lot.

prettyshady 10-12-09 11:37 AM

Is it possible to damage a frame from applying too much force when trying to free a stuck seat post?

metalchef87 10-12-09 11:42 AM

How do I know if I have an aluminum or steel post? I am going to run to the store and get some pb blaster I suppose and maybe some ammonia...this really stinks!

I am doing my best to not ruin the frame, and I am tempted to just say forget it and ride it with the post too short...off to the store.

prettyshady 10-12-09 11:43 AM


Originally Posted by metalchef87 (Post 9843674)
How do I know if I have an aluminum or steel post?

a magnet won't stick to an aluminum post but will to a steel post.

Vinci 10-12-09 11:45 AM

PB Blaster works miracles. If your bottom bracket isn't a modern "sealed" type, you may need to clean/repack it when you're done, as Blaster will dissolve grease and may well get to your bearings.

Barchettaman 10-12-09 11:46 AM

Whilst it is true that this subject has been frequently covered, for people like me (with a completely stuck seatpost) it's good to see it asked again. Practically every time someone has a slightly different method that they share, which gives me something else to try on my bl00dy stuck post.

Compare and contrast with any thread about clinchers v. tubulars, which is a fairly pointless thing to go over as it is so much to do with personal choice and preference, and always disintegrates into a micturation tournament.

Cheers all
Simon

metalchef87 10-12-09 11:59 AM

I have a steel post! This is good right? I first am going to try a tip someone gave to boil water, pour over the ST and allow to cool...supposedly this will expand both, but when the SP contracts it will break the seal and it should come out...won't do damage to the paint or bike...so I am trying this next...if that fails then were off to try pb blaster

miamijim 10-12-09 12:03 PM


Originally Posted by prettyshady (Post 9843644)
Is it possible to damage a frame from applying too much force when trying to free a stuck seat post?

Yes.

SJX426 10-12-09 12:06 PM

PB Blaster is used by 4x4 guys to free suspension parts that have been rusted on for decades. It works.

Although the seat attached to the post provides good leaverag, I would expect a pipe wrench would be even better. Just expect to damage the post. Since it is a steel post in a steel frame with rust as the glue, this just might be a supper challenge (this is what PB Blaster was made for).

cman 10-12-09 12:11 PM

Boiling water is a great idea as it won't harm the paint badly like a heat gun or torch might.

I had one that somebody had cut the top of the seatpost off. Aluminmun in a steel frame. No effective way to grab onto it. I took an old bent frame and drilled a hole in the Head Tube. Then driller a hole in the stuck seattube. Bolted together and twisted away. Broke the bond that ammonia or PB couldn't get too.

Chombi 10-12-09 12:17 PM

Thing is, the seatpost depends on close contact/friction with the steel seat tube for it to stay put and not slipping down from the rider's weight and shock. I'm wondering why anyone never cam up with a sort of thin isolator sleeve made out of a material that will not react with both metals and provide the needed grip to keep the seatpost securely clamped on to the frame. smaller diameter seatposts can be obtained to accomodate such sleeves. Seizing aluminum seaposts on steel frames had been an age-old problem with that seems to have escaped solution before the end of the steel frame era.
On a related topic, the seatpost on my 84 Peugeot PSV is held on to the frame with a Allen head jamb bolt mounted on what really is a waterbottle boss, about an inch and a half below the top of the seat tube, between the fastback seat stays. The proprietary JPR aluminum seatpost that came with the bike has a groove machined on to the back side of the seatpost tube where this jamb bolt presses on inside the seat tube and keeps the post/saddle in place and straight. I'm not sure if the setup will avoid the corrosion/seizing problem, but I was always leery of this seatpost anchorage design by Peugeot that seems to have been done on only one or two model years (1984-5?) on their Vitus and maybe Reynolds 501 tubed bikes. I was thinking that maybe I and others here can use the anti seizing compound that mechanics put on spark plug threads to prevent them from seizing/galling on to aluminum engine heads??

Chombi
84 Peugeot PSV

23skidoo 10-12-09 12:18 PM

Great recommendations from everyone; I've got one that's been marinating in Liquid Wrench for a month or so because it's been particularly stubborn. I've been able to remove most of the stuck seat posts by removing the wheels, chain, saddle, bars and stem, then clamping the seatpost firmly in a sturdy bench vise and using the frame itself to twist side-to-side to break the adhesion. Once you get the post out it's probably a good idea to take the frame in to a decent lbs and have them hone out the seat tube to clean out any remaining gunk and corrosion. Good luck. Now if I could only get the danged Death Fork out of the Viscount Aerospace I scored early this summer....

Iowegian 10-12-09 12:30 PM

If you don't mind trashing the post I've had luck with a vice grips and dead blow hammer. The first step is always to use a penetrant like PB Blaster and give it time to work. Then heat helps. I think the heat helps soften the rust bond more than actually expand the metal. I use a propane torch for heat and have never damaged the paint but YMMV. I like the hammer/vice grip method since the force is nearly all torque on the post. Plus it's very satisfying to hit the post over and over until it moves:D Once it starts moving keep going around in a spiral motion until it's free.

metalchef87 10-12-09 01:01 PM

I just applied the first good soaking of PB blaster...the hot water idea didn't work, unfortunately. I did bend the ST Clamp out just a little bit, which gave me some area to squirt the blaster into, also on top of the post/tube area...I am hoping that it breaks free soon. I'll be extremely happy when it does!

ScottRyder 10-12-09 01:14 PM


Originally Posted by metalchef87 (Post 9844199)
I just applied the first good soaking of PB blaster...the hot water idea didn't work, unfortunately. I did bend the ST Clamp out just a little bit, which gave me some area to squirt the blaster into, also on top of the post/tube area...I am hoping that it breaks free soon. I'll be extremely happy when it does!

I have a Masi Gran Corsa that had a horribly stuck post. I kept spraying the Blaster in from the top, no go for a month. Then I friend suggest I turn the bike over and squirt it thru the bottle braze ons in the seat tube. duh .. popped out the next day.

Scott

wrk101 10-12-09 01:37 PM

Also on ammonia, get the strong stuff. The dilute version sold at Walmart or your favorite grocery store is worthless.

Zaphod Beeblebrox 10-12-09 01:43 PM

This might be a bit obvious, but be sure to service the BB after all this... You know where the myriad of stuff thats being poured down your seatpost ends up.


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