Shim 26.4 to 27.2 seatpost

[still me]

vintage post, vintage bike... I really want to use this model post but
I can't seem to find a 27.2. So, while I watch Ebay for a few years..

Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
obtain something like brass stock in the exact thickness needed, or
can I hack the fit with a Coors can until it feels right?

Opinions and flames welcome,

 

[[email protected]]

On May 4, 3:20 pm, still me <[email protected]> wrote:
> vintage post, vintage bike... I really want to use this model post but
> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
> obtain something like brass stock in the exact thickness needed, or
> can I hack the fit with a Coors can until it feels right?
>
> Opinions and flames welcome,

Dear SM,

This shim is for 25,4 to 26.1, but it would probably open just fine
and work for 26.4 to 27.2:

http://www.bikeparts.com/search_results.asp?ID=BPC303103

The lip stops it from falling down into the frame.

Cheers,

Carl Fogel

 

[Hank Wirtz]

On May 4, 2:20 pm, still me <[email protected]> wrote:
> vintage post, vintage bike... I really want to use this model post but
> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
> obtain something like brass stock in the exact thickness needed, or
> can I hack the fit with a Coors can until it feels right?
>
> Opinions and flames welcome,

What kind of post? (My Peugeot takes a 26.4, and I usually have the
opposite problem)

 

[landotter]

On May 4, 4:20 pm, still me <[email protected]> wrote:
> vintage post, vintage bike... I really want to use this model post but
> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
> obtain something like brass stock in the exact thickness needed, or
> can I hack the fit with a Coors can until it feels right?
>
> Opinions and flames welcome,

Better yet, Ebay the post to somebody that needs a 26.4 post and use
the profits to get a very common 27.2mm post. Nashbar's got a carbon
one on sale for $20 for chrissakes.

 

[landotter]

On May 4, 6:09 pm, landotter <[email protected]> wrote:
> On May 4, 4:20 pm, still me <[email protected]> wrote:
>
> > vintage post, vintage bike... I really want to use this model post but
> > I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
> > Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
> > obtain something like brass stock in the exact thickness needed, or
> > can I hack the fit with a Coors can until it feels right?
>
> > Opinions and flames welcome,
>
> Better yet, Ebay the post to somebody that needs a 26.4 post and use
> the profits to get a very common 27.2mm post. Nashbar's got a carbon
> one on sale for $20 for chrissakes.


Reread the post. It's a style thing, then? Use a proper shim for such
a large difference, fishing beer can stock out of your seat tube is
lame.

 

[Sir Ridesalot]

On May 4, 5:20 pm, still me <[email protected]> wrote:
> vintage post, vintage bike... I really want to use this model post but
> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
> obtain something like brass stock in the exact thickness needed, or
> can I hack the fit with a Coors can until it feels right?
>
> Opinions and flames welcome,


Hi there.

I assume the frame is steel?

There are quite a few 27.2 seat posts, including aero ones, on Ebay.

However if yoiu really want to use the seat post you have you can shim
it. The best way is to use a proper purpose made shim. You can easily
do it yourself though.I have done this in the past for people who do
not have much money. I make the shim at least 3 inches long so that a
long area of the seat post is supported by the shim. I leave a bit,
say 1/16 the inch above the seat tube when I insert the shim without
the seat post. I gently peen this 1/16 bit over to the outside so it
becomes a lip and that prevents the shim from falling into the seat
tube if you remove the seat post later.

Beer can aluminium works well but you may require 2 layers. A good
source of thin aluminium stock is a good hobby shop. There you should
be able to bget something very close to the exact thickness you need.

Cheers from Peter

 

[Joel Mayes]

On 2007-05-04, still me <[email protected]> wrote:
> vintage post, vintage bike... I really want to use this model post but
> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
> obtain something like brass stock in the exact thickness needed, or
> can I hack the fit with a Coors can until it feels right?
>
> Opinions and flames welcome,
>

Cheapie hybrids come with a thicker seat tube shim from the
factory so I don't see any problems with shimming out that much.
I'd get a brass tube of the right size rather than use many layers of
tin can

Cheers

Joel

--
Human Powered Cycles | High quality servicing
[email protected] | Low cost 2nd hand bikes
www.humanpowered.com.au | Bicycle re-use centre

 

[sergio]

On May 4, 11:20 pm, still me <[email protected]> wrote:

> Opinions and flames welcome,

Get yourself a sheet of those used as transparencies, cut out a
trapezoid and insert it upside down (possible two layers).
Inserting the trapezoid upside down allows you to insert it just as
needed so that exact thickness is no issue. Make it so that part of it
will remain sticking out, to be trimmed at last.
No possibility that it may fall in later on upon removing the post.
However, should you unduely worry, you will always be able scoop it
out with a DT swiss spoke, or just leave it there. It's just so light!

Beware!: International Patent Pending

Sergio
Pisa

 

[Kinky Cowboy]

On Fri, 04 May 2007 21:20:00 GMT, still me <[email protected]>
wrote:

>vintage post, vintage bike... I really want to use this model post but
>I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>
>Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
>obtain something like brass stock in the exact thickness needed, or
>can I hack the fit with a Coors can until it feels right?
>
>Opinions and flames welcome,

That's quite a thin shim (0.4mm wall), but my local machinist just
made me a 100mm long shim from 28.6 to 29.7 (0.55mm wall) with a lip
to stop it falling down the tube, so it can probably be done. Quite
expensive (GBP25, about $50), but nice and you know it will be exactly
the right size

Otherwise, it's also almost exactly 15 thousandths of an inch, and a
hobby/model shop should have brass or nickel plated steel sheet in
15thou so you can make your own. I did this myself to fit a 26.4 post
in a 26.8 frame (real difference 8thou, I used 10thou nickel plated
steel sheet) and it's worked problem free for 20 years.

Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

 

[[email protected]]

On 4 May 2007 15:55:57 -0700, [email protected] wrote:

>On May 4, 3:20 pm, still me <[email protected]> wrote:
>> vintage post, vintage bike... I really want to use this model post but
>> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>>
>> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
>> obtain something like brass stock in the exact thickness needed, or
>> can I hack the fit with a Coors can until it feels right?
>>
>> Opinions and flames welcome,
>
>Dear SM,
>
>This shim is for 25,4 to 26.1, but it would probably open just fine
>and work for 26.4 to 27.2:
>
>http://www.bikeparts.com/search_results.asp?ID=BPC303103
>
>The lip stops it from falling down into the frame.
>
>Cheers,
>
>Carl Fogel

Sloppy typing---the shim is for 25.4 to 26.2. The comma is more
embarrassing than the mistaken .1 mm.

CF

 

[still me]

On 4 May 2007 16:04:51 -0700, Hank Wirtz <[email protected]> wrote:

>On May 4, 2:20 pm, still me <[email protected]> wrote:
>> vintage post, vintage bike... I really want to use this model post but
>> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>>
>> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
>> obtain something like brass stock in the exact thickness needed, or
>> can I hack the fit with a Coors can until it feels right?
>>
>> Opinions and flames welcome,
>
>What kind of post? (My Peugeot takes a 26.4, and I usually have the
>opposite problem)

It's a Simplex post. Not the early steel (defensive weapon) post, not
the next version of that exact post in alloy, but one that looks more
like a stronglight post (or the SR laprade copy) of that era with
machined v-grooves. Sports the Simplex star logo on the side. Predates
the last Simplex post (the one with the stick on label and the square
machined grooves).

You don't see many of them around anymore, and almost never in 27.2.
Matches the rest of the bike well vintage wise so I'd like to use it.

 

[still me]

On Sat, 05 May 2007 12:01:20 -0600, [email protected] wrote:

>>
>>http://www.bikeparts.com/search_results.asp?ID=BPC303103
>>
>>The lip stops it from falling down into the frame.
>>
>>Cheers,
>>
>>Carl Fogel
>
>Sloppy typing---the shim is for 25.4 to 26.2. The comma is more
>embarrassing than the mistaken .1 mm.

Good thing you corrected that. I thought you might be going Euro on
me.

Thanks for all the help folks, I'll try one of these options.

 

[Donald Gillies]

still me <[email protected]> writes:

>vintage post, vintage bike... I really want to use this model post but
>I can't seem to find a 27.2. So, while I watch Ebay for a few years..

Why don't you tell us what kind of post you are looking for, and we
may be able to send you in the right direction ....

- Don Gillies
San Diego, CA

 

[Donald Gillies]

still me <[email protected]> writes:

>On 4 May 2007 16:04:51 -0700, Hank Wirtz <[email protected]> wrote:

>>On May 4, 2:20 pm, still me <[email protected]> wrote:
>>> vintage post, vintage bike... I really want to use this model post but
>>> I can't seem to find a 27.2. So, while I watch Ebay for a few years..
>>>
>>> Is it OK to shim from 26.4 to 27.2 ? If I do, should I carefully
>>> obtain something like brass stock in the exact thickness needed, or
>>> can I hack the fit with a Coors can until it feels right?
>>>
>>> Opinions and flames welcome,
>>

Any kind of 0.8mm shim will work. So if you have a 25.4 to 26.2mm
shim, then it will work. If you have a 29.2 to 30.0 shim then it will
work (although it may be too wide and you might have to trim it down.)
A good quality one will have a lip so that it doesn't slide down into
the tube of the bike.

I find that tandem supply houses carry the most shims because nearly
every suspension post on earth is 25.4, which never matches the tubes
in a good-quality tandem.

- Don Gillies
San Diego, CA

 

[still me]

On 5 May 2007 20:51:32 -0700, [email protected] (Donald Gillies)
wrote:

>
>Why don't you tell us what kind of post you are looking for, and we
>may be able to send you in the right direction ....
>
>- Don Gillies
>San Diego, CA

I'll snap a photo of this one and post it for review.