Lost post

[Weatherlawyer]

Originally posted to uk.rec.cycling:

bought a bike for =A315 then spent another =A315 on a seat post the old one being hacked off and the residue left in the frame where it can not be easily convinced of the error of its ways.

I can't use the present post without cutting it down and don't want to cut it down. It's worth more than the bike at the moment.

The pedal crank housing prevent pushing the old piece out and it may have some rust or chrome peel or just dirt... whatever holding it in situ.

Anyone ever come across anything like this?

[Dave Plowman (News)]

I bought a bike for £15 then spent another £15 on a seat post the old

Try a Rawlbolt or similar fixing (steel) that will grip inside the offending tube. You might need a longer bolt than the one supplied. Something like a suitable 1/2 socket should work as a spacer if the post is cut off flush with the frame. Use loads of penetrating oil

[dennis]

snip stuff about lost tube..

No.

But cutting a couple of barbs in a piece of tube (copper water pipe?) should do it.

[Cicero]

=================================== Following on from the idea of a rawlbolt you might be able to borrow an expanding reamer which will give finer control, tighter grip and possibly longer reach.

Try a local engineering shop for the reamer.

Cic.

[Dave Plowman (News)]

I'd not lend an expanding reamer for such a task - do you know what they cost? ;-) A suitable Rawlbolt should cost about a quid.

[:Jerry:]

>>> I bought a bike for £15 then spent another £15 on a seat post the >> old

ERR!!!!!! Not a reamer, not unless you want to wreck it. :~(

There are proper tools for extracting internal bushes etc. These tools are two part, the outer part has an external 'lip' and an female cone whilst the inner part has a male cone (these parts work in the a similar way as rawbolts) the inner part can be attached to a slide hammer or other means of extraction.

[manatbandq]

Fashion something similar to the way the handlebars are held in, to grip the lost seatpost.

MBQ

[:Jerry:]

The problem with something that relies solely on expansion to grip the part will be that to achieve the required friction you are in danger of also expanding the part against the outer tube - exactly how a rawbolt remains in the floor etc. in fact!

[cupra]

> I bought a bike for £15 then spent another £15 on a seat post the old

How about a headset star nut? (it may need some adjusting due to the seatpost internal diameter, you can bend the 'stars' a little from experience)

local bike shop could probably do you one for pennies - all you need is a longish bolt and a plate with hole drilled in.....

[Weatherlawyer]

Thanks all for the interest. I am quite surprised at the ingenuity of some much superior to the inhabitants from the op site who already have a knowledge of the plug-ins suggested here.

I should have posted here first. I used to have a junk pile of different headsets. But of course after keeping them for years I did the sensible thing with them and ditched the lot. I might take apart a bike I still have for one though.

If as is most likely it isn't long enough, I'll try some of the others. The rawlbolt idea is next, I think, if it will expand without some grip first. I can't remember.

Cheers.

[Colin Wilson]

I think you missed the point of this suggestion tbh - push the rawlbolt *beyond* the end of the post, and let the wings act against the end of the tube.

BICBW :-}

[Cicero]

>>>>> I bought a bike for £15 then spent another £15 on a seat post the

=================================== I'll stay with my suggestion of a reamer. Seat posts are a fairly loose sliding fit and although my suggestion is for an unconventional use for the reamer it should only need a light grip to remove the offending tube with no damage to the reamer.

I would guess that if the tube was well lubricated and then the bicycle turned upside down a bit of judicious tapping around the outer tube would release the inner bit unless it has been splayed out by previous attempts to remove it.

Cic.

[Clint Sharp]

In message , Weatherlawyer writes

Threaded bar, washers nuts and a little fiddly application. Drop bar down seat post, slip washers onto bar, attach nut and use to pull the post out. Use a socket from a socket set as a shim at the top and wind the bar out.

[:Jerry:]

Yes but a rawbolt forms a wedge, it's this wedge that stops the outer part pulling out the floor etc. so you'll either end up tightening it against the outer tube in the first place or it moving up into the in side tube and doing as I described.

[:Jerry:]

>>>>>>> I bought a bike for £15 then spent another £15 on a seat post the

Then sorry but you are a clueless idiot who should not be allowed within a 100 miles of an engineering workshop!

Seat posts are a fairly loose

Except when rusted in....

and although my suggestion is for an unconventional use for

Except that you are attempting to grip with something that has cutting edge 'blades' designed to remove metal - you'll end up blunting the cutting edge - if a reamer is tight then it's the wrong size or being forced to quickly. If the in side tube is as loose as you suggest it should be then Dave's suggestion regarding a rawbolt should work without damaging anything.

[:Jerry:]

Am I missing something here, lets give some suggested dimensions;

Tube to be removed : i/d dia' = 23mm (o/d = 25mm) Outer fixed tube : i/d = 25.5mm

So the washer can't be any wider than 23mm o/d, how can that but up and remove the tube when the washer would need to be (at least) 23.2mm o/d [1] but then if it was it could not fit down the 25mm i/d..... As I said, errrr?

[1] that still only gives a 1mm to pull against

[Cicero]

>>>>>>>>> I bought a bike for £15 then spent another £15 on a seat post the

================================== Obviously you're not prepared to experiment to find a solution to a problem. There are times when it's worth risking damage to a tool if it achieves the desired result. Few tools last forever.

My reamers have been in use for many years and they're in good condition but if I had a bicycle that was useless and could be made serviceable by using a tool in a possibly damaging way I wouldn't hesitate to do so. Reamers are cheaper than bicycles and easily replaced or repaired.

Cic.

[:Jerry:]

Of course I am, what I'm not prepared to do (short of life or death) is knowingly bugger up an adjustable reamer than could well cost more than buying a new bike would!

[:Jerry:]

Oops! that should have read ...but then if it was it could not fit down the *23mm* i/d.....

[Arthur2]

bought a bike for £15 then spent another £15 on a seat post the old one being hacked off and the residue left in the frame where it can not be easily convinced of the error of its ways.

I can't use the present post without cutting it down and don't want to cut it down. It's worth more than the bike at the moment.

The pedal crank housing prevent pushing the old piece out and it may have some rust or chrome peel or just dirt... whatever holding it in situ.

Anyone ever come across anything like this?

I'd use 12" of 22mm copper pipe slit down its length. Then scan the inside of the problem and apply some sort of cement glue to locations on the copper pipe outer surface to line up with 3 or 4 good areas of the stuck part. let the cement dry and twist and pull and curse like you have never cursed before. And depending on if you curse well enough, it'll shift.

Arthur