Myron

Hello. Hope someone can help me with a situation I've got with a cycle. I have two cycles where on one I've managed to raise the seat post with some difficulty and on the other cycle the seat is stuck down, yet on both cycles I can very easily turn the seat-post round. (Obviously with the QR clamp released.) Does anyone have any good tips on how to release the stuck seat-post so I can raise it out of the other cycle? These are new cycles.

It looks like on the seat-tube I managed to raise that there is burring (if I've used the right word) along the length of the seat-tube.

I can't post any pictures at the moment as this is my first post.

andrewclaus

What are the materials of the frames and seat posts? Use a magnet to determine if anything is steel. Have you used penetrating oil yet?

One method involves a bench vise and a helper, with the wheels removed and the seat post in the vise.

soyabean

Throw in whatever can seep into there, motor oil, even WD40 will work here since it's not seized stuck.

soyabean

Why would the OP have to do that if the bikes are brand new and the seatpost does turn?

dedhed

The vise holds the seatpost and the frame gives you a big handle to turn & pull. Much bigger than holding the frame and pulling on the seatpost.

Crankycrank

I think if the bikes are new, you should take it back to the shop and let them handle it since even though this is a pretty simple problem if anything were to get damaged while you were trying to remove the posts, they could claim it was your fault and leave you with the cost of repair/replacement.

Myron

Yes. They are new. That is what is going to happen. I just don't understand how its happened. Didn't think about using a magnet to see of it's steel aluminium or some sort of alloy.

andrewclaus

I totally missed the sentence about them being new. Poor reading comprehension that early in the morning I guess.

Myron

I'm going to ask a daft question. Are there seat posts that have circular burring along the length of the seat-post as opposes to smooth seat-posts? (It would be easier to show the issue, but I can't put up a picture until I've written 10 posts minimum.)

dedhed

Yes.

Myron

Thank-you for that advise.

soyabean

This is a very BAD "advise" to follow for a new bike.

Go back to the LBS (preferred where you purchased the bikes from), they will figure it out.

Myron

I'm a newbie MIAS L3 cycle mechanic and part of this is the issue I have now and the other part is CPD. The reason I'm trying to find out how to do this for myself is when I have any inclusive cycling sessions running, if I end-up with a seat post stuck down then I can, hopefully, free it, but yes, understandable that this should not happen. As far as I'm aware this stuck down seat-post is not due to the set post being pushed too far down into the seat-tube. Plus, I don't think I would like to crush the seat tube in a vice which could make the clamped part of the seat-post oval. Oval does not fit into a circle and I think if that happened then the seat-tube would be truly jammed in.

By rights it should be a trained member of staff that would be adjusting the bike, but I can see someone trying to adjust a bike that should not when I'm not looking.

Myron

Four more posts from me and I'll be able to show everyone on this thread the condition of the seat tube. :-)

soyabean

I learned a bit from a friendly LBS.

I learned a lot more when working for a LBS.

I get my knowledge from whereever I can.

I would be a fool to refuse hands-on knowledge that could be easily obtained locally.

Myron

Finally I can show you what the issue is with this pesky seat post.

base2 

I'm not seeing the issue. The circumferential texture is from machining during manufacture.

Your post & seat tube should be greased though. Any generic plain bearing grease ought to work well enough to prevent binding. Your bike shop should have applied it during assembly.

(I'll reserve judgement whether or not your bike shop is reputable for another time.)

Seeing that they couldn't bother to take the time to properly grease the seat post, you may want to take it upon yourself inspect & grease all the other thread interfaces on the bike to prevent a lot of future heartache.

Myron

Now there is a good question. I will check this today. Won't be able to check this on the second cycle where the seat post is stuck down, but will try again to free it Bike shop is a reputable one. The leisure trust I work for had purchased numerous things from that and there have not been any problems.

dabac

1) better seat posts usually have an integrated saddle clamp. Hold this in the vise to avoid ovalizing the seat post.
2) I’ve got some split wooden blocks with seatpost-sized holes in them which allows me to clamp simple seat posts w/o ovalizing them.
3) to ovalize a seat post to the point of making it (more) stuck or damaging the seat tube, you’d basically have to grasp it right outside the seat tube. If you clamp it 4” away, it’s not a problem.

Myron

Problem was solved at a cycle workshop, but there where four cycle mechanics hanging off the cycle. I'm guessing two holding on and the other two pulling at the seat.
Seems the bottom of the seat-post got stuck on a weld within the down-tube. Seat post was shortened. I had no chance of doing this myself.

Case now closed. :-)