FIXED: Interesting seat post issue - diameter too small

[Gsinill]

So I just got a beautiful old Super Record 27.2mm seat post,
When I tried to install it on my Appel, I couldn't get it tight enough.
After checking the actual diameter, I found out that right around the limit line it "shrunk" from 27.2 to almost 27.0. Looks like one of the previous owners must have tightened it like nuts.

Did anyone ever come across this issue? Any fix? I am thinking about some tool, gizmo that would allow me to spread it back to it's original width. Something like the mechanism in a quill stem.

Otherwise it's a beautiful seat post!

Thanks in advance.
GS

[rice rocket]

Shim it with a cut up soda can.

[Gsinill]

Shim it with a cut up soda can.

Even though this would probably work, not sure the German in me likes the idea. ;)

Thanks though.
GS

[rice rocket]

Buy a new seatpost.


Better? ;)

Unless you have a mandrel the exact diameter to shove up in the tube, there's not really any other solution than shimming it. You could lathe a ridiculously overengineered shim if that satisfies the German in you, but machining super thin metals wouldn't be on the top of my hobby list.

[aramis]

seriously just shim it. You can do it so it is pretty much impossible to tell you are using a shim.

[fiamme red]

I think a Coke can would be too thick for a difference of 0.14 mm. Try aluminum foil or maybe electrical tape.

[aramis]

I think a Coke can would be too thick for a difference of 0.14 mm. Try aluminum foil or maybe electrical tape.

27.06 + .14 = 27.2 , seems perfect actually.

[David Kirk]

As odd as it sounds a 27.2 post should not measure 27.2. Crazy stuff eh?

The number 27.2 refers to the size hole the post should fit in and not it's actual size. A post called a '27.2' should measure just about 27.1 - 27.15. Here's the second odd thing-----there is no actual agreed upon industry standard for the O.D. of a 27.2 post so they vary.

Old campy stuff tended to run small and new stuff tends to run large.

Not sure this is of any help to you but it might be informative.

Dave

[jds108]

go with the coke can. If a full wrap around the post is too much, then just wrap 1/2 diameter of the post. The shim only needs to be a inch or two tall.

Use some carbon assembly paste between the post and shim and between the shim and frame. That'll keep it from slipping once installed. The carbon assembly paste has little tiny particles suspended in grease. Those little particles create a lot of friction thus retarding slippage...

[KidWok]

Even though this would probably work, not sure the German in me likes the idea. ;)

Thanks though.
GS

Use a German beer?

Tai

[Columbus SLX]

Buy a new seatpost.
Better? ;)
Unless you have a mandrel the exact diameter to shove up in the tube, there's not really any other solution than shimming it.

Or, take it to a bike shop with a knurling tool (http://www.bikesonline.com/ja-stein-knurling-tool-knurling-tool.htm). This will increase the diameter of a round object enough for a snug fit. Just be sure to mark with tape the point where you want it to stop in the frame so they can knurl just below it (where the binder bolt is.)

[buldogge]

^^^Yep...This is the right answer. I had to knurl a Thomson 27.2 for my Chesini...kept slipping.

If no local bike shops have the knurling tool, then any small machine shop should be able to chuck it up in a lathe and knurl the area around where you are clamping.

Good luck...

-Mark in St. Louis

Or, take it to a bike shop with a knurling tool (http://www.bikesonline.com/ja-stein-knurling-tool-knurling-tool.htm). This will increase the diameter of a round object enough for a snug fit. Just be sure to mark with tape the point where you want it to stop in the frame so they can knurl just below it (where the binder bolt is.)

[KidWok]

I had a Ritchey Wet Red post that measured like 27.35. I think the post itself was probably 27.2, but the powdercoat added the additional thickness. It was a royal pain...had the post buffed down to the metal with a wire brush below the insertion line, but not before I crammed that sucker so far in that I couldn't get it out myself.

So there's your answer...take it to a powdercoater.

Tai

[Gsinill]

Or, take it to a bike shop with a knurling tool (http://www.bikesonline.com/ja-stein-knurling-tool-knurling-tool.htm). This will increase the diameter of a round object enough for a snug fit. Just be sure to mark with tape the point where you want it to stop in the frame so they can knurl just below it (where the binder bolt is.)

You da man, that's exactly what I was looking for :banana:


Tried soda can, electrical tape but still have to figure out how my Schneider Weissbier as suggested by Tai would do the trick ;)

Cheers
GS

[Columbus SLX]

:banana::hello::banana:

[Gsinill]

:banana::hello::banana:

Well, just called the 3 major bike shops in the northern Chicago burbs and none of them ever even heard of it. Machine shop might be a better option.
Maybe I should open a knurling business LOL

[jr59]

A call to Peter and Jim @ http://www.vecchios.com/where.html

Would do the trick. Trust me on this!

[jmoore]

Use a German beer?

Tai

winner

[Columbus SLX]

I know Peter has a knurling tool. I think he's mentioned it before.

[Gsinill]

A call to Peter and Jim @ http://www.vecchios.com/where.html

Would do the trick. Trust me on this!

You mean shipping it out to them to have it fixed???

[Columbus SLX]

You mean shipping it out to them to have it fixed???

Sure, I mean, I'd do it for ya but I'm moving out of my shop next week and won't have the tools again for a while.

[zmudshark]

My Appel was a 27.4 seat post.


Just sayin'

[buldogge]

If you to mail it to me, with the section you want knurled marked, I will knurl it for you.

-Mark in St. Louis

[pinkshogun]

peen it.....its sorta like knurling if you dont have the tool.

use a hammer and punch to make equidistant marks around the post. make sure you peen the area of the post that is inside the seat tube

[oldpotatoe]

So I just got a beautiful old Super Record 27.2mm seat post,
When I tried to install it on my Appel, I couldn't get it tight enough.
After checking the actual diameter, I found out that right around the limit line it "shrunk" from 27.2 to almost 27.0. Looks like one of the previous owners must have tightened it like nuts.

Did anyone ever come across this issue? Any fix? I am thinking about some tool, gizmo that would allow me to spread it back to it's original width. Something like the mechanism in a quill stem.

Otherwise it's a beautiful seat post!

Thanks in advance.
GS

Knurl it..any decent bike shop will have this tool.

[oldpotatoe]

Well, just called the 3 major bike shops in the northern Chicago burbs and none of them ever even heard of it. Machine shop might be a better option.
Maybe I should open a knurling business LOL

YGBSM..what is wrong with bike shops these days? It ain't that hard.

[Gsinill]

My Appel was a 27.4 seat post.


Just sayin'

Interesting, but the American Classic one the bike came with and a Thomson both in 27.2 work just fine...

[Gsinill]

If you to mail it to me, with the section you want knurled marked, I will knurl it for you.

-Mark in St. Louis

I still have a few ideas on how to fix it, if all that doesn't work I might send it to you. Thanks a lot, really appreciate the offer.

[R2D2]

Even though this would probably work, not sure the German in me likes the idea. ;)

Thanks though.
GS

Well buy one that fits.

[Gsinill]

Beer was only involved in coming up with the solution...

Like my grandfather used to say: "There is always a solution, all it takes is enough persistence, stubbornness and brute force!"

:banana:

[likebikes]

what happened?

[shovelhd]

Book tape?

[Gsinill]

Book tape?

Nope, $2 spent on a 1/2 x 5 inch water pipe at Ace, some nuts and bolts, a little bit of sawing and grinding and ready was the "seat post widening" gizmo.
I guess the rest is pretty self-explanatory :)

[DRZRM]

Let me be the first to say I am very impressed by your ingenuity, and a bit concerned about the structural safety of that post. I never think of aluminum (right?) as a good medium for manhandling.

[Columbus SLX]

Nope, $2 spent on a 1/2 x 5 inch water pipe at Ace, some nuts and bolts, a little bit of sawing and grinding and ready was the "seat post widening" gizmo.
I guess the rest is pretty self-explanatory :)

Holy crap, that's pretty awesome.

:beer:

[Gsinill]

Let me be the first to say I am very impressed by your ingenuity, and a bit concerned about the structural safety of that post. I never think of aluminum (right?) as a good medium for manhandling.

Thanks, yep it's aluminum.
Maybe it's now time to switch to all black components which I am contemplating anyway ;)