Carbon seat post damage

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

Not using a carbon seatpost is a good advice but if you insist using one you
can use this grease:

http://www.bike-components.de/catalog/product_info.php?cPath=282_78&products_id=12414&language=en

It prevents seizing and increasing friction so you don't need high torques
to prevent slipping.

Lou

Thanks, sounds worth checking out.
The reason I went for a carbon seatpost is that I was advised I'd need
one to dampen the road vibrations from the stiff alu frame (I
previously exclusively road steel frames).
I'm not 100% about replacing the seatpost with the same again.

Henry

"Henry" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Thanks, sounds worth checking out.

Yes it is. It's really 'funny' stuff ;-)

Quoted message said:

The reason I went for a carbon seatpost is that I was advised I'd need
one to dampen the road vibrations from the stiff alu frame (I
previously exclusively road steel frames).
I'm not 100% about replacing the seatpost with the same again.

I don't believe that a carbon seatpost makes much of a difference. I build
up a 6.75 kg roadbike with carbon all over the place except seatpost, stem
and handlebar.

Lou

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

Make sure you use a clamp designed for carbon posts. They are supposed
to even the load a bit:
http://tinyurl.com/cuyww

Joseph

Thanks Joseph,
That looks exactally like what's needed!

Henry

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.

Yes.

Don't.

Get a metal one.

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

Take the clamp and rotate it 180 degrees so that the split in the clamp
in opposite the split on the seatube. When they both lineup, the 'hole'
becomes more oval and crushing can occur. Also use of a Campagnolo
clamp will help.

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

I would use a torque wrench to tighten the bolt to manufacturers specs.
--------------
Alex

email hidden said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

Check out the Easton CF posts, I've been using an EC70 with good
results.
http://www.eastonbike.com/PRODUCTS/POSTS/post__top.html

Life is Good!
Jeff

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage to
my carbon seat post at the point where the clamp compresses the post.
It's a 27.2 deda post 320 in length, going into an alu frame. About
18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

90% probability of it being merely cosmetic. apply nail polish and
re-fit to bike. go ride. do not use grease.

jim beam said:

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage
to my carbon seat post at the point where the clamp compresses the
post. It's a 27.2 deda post 320 in length, going into an alu frame.
About 18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

90% probability of it being merely cosmetic. apply nail polish and
re-fit to bike. go ride. do not use grease.

Whoohoo! Someone else who thinks that it's not that big of a deal!
--
Phil, Squid-in-Training (riding cracked/repaired frames)

Phil said:

jim beam said:

Quoted message said:

I stripped out my summer bike at the weekend to find a bit of damage
to my carbon seat post at the point where the clamp compresses the
post. It's a 27.2 deda post 320 in length, going into an alu frame.
About 18-19cm of the shaft exposed.

When installed in a new frame I made sure there was no grease in the
seat tube, and even cleaned it with isoproponol, and let dry, just to
be safe.
It was slipping a bit at first, but a quarter turn of an allen key on
the clamp sorted that.
Now on inspection I seem to have crushed the pillar slightly: looks
like I'm going to have to replace it rather than risk a breakage and
nasty accident!

Please does anyone out there have any advice on installation of a
carbon seat post in an alu frame? I'm a bit concerned the same thing
will happen again.
Thanks

Henry

90% probability of it being merely cosmetic. apply nail polish and
re-fit to bike. go ride. do not use grease.

Whoohoo! Someone else who thinks that it's not that big of a deal!
--
Phil, Squid-in-Training (riding cracked/repaired frames)

Any place that attaches rider to bike, that is 'flawed', like a
potentially cracked seatpost is a bad idea to use. For somebody who
hasn't seen the mentioned seatpost, you are eager to say it's only
cosmetic. I think it is not a good idea to use carbon fiber bits that
are damaged, like hbars or seatposts.

Qui si parla Campagnolo said:

Phil said:

jim beam said:

[email hidden] wrote:

>I stripped out my summer bike at the weekend to find a bit of damage
>to my carbon seat post at the point where the clamp compresses the
>post. It's a 27.2 deda post 320 in length, going into an alu frame.
>About 18-19cm of the shaft exposed.
>
>When installed in a new frame I made sure there was no grease in the
>seat tube, and even cleaned it with isoproponol, and let dry, just to
>be safe.
>It was slipping a bit at first, but a quarter turn of an allen key on
>the clamp sorted that.
>Now on inspection I seem to have crushed the pillar slightly: looks
>like I'm going to have to replace it rather than risk a breakage and
>nasty accident!
>
>Please does anyone out there have any advice on installation of a
>carbon seat post in an alu frame? I'm a bit concerned the same thing
>will happen again.
>Thanks
>
>Henry
>

90% probability of it being merely cosmetic. apply nail polish and
re-fit to bike. go ride. do not use grease.

Whoohoo! Someone else who thinks that it's not that big of a deal!
--
Phil, Squid-in-Training (riding cracked/repaired frames)

Any place that attaches rider to bike, that is 'flawed', like a
potentially cracked seatpost is a bad idea to use. For somebody who
hasn't seen the mentioned seatpost, you are eager to say it's only
cosmetic. I think it is not a good idea to use carbon fiber bits that
are damaged, like hbars or seatposts.

what is "damage"? do we /know/ the op can differentiate between a crack
in the matrix and a scratch in the clearcoat? the context of their post
says "no". on that basis, the latter is by far the most likely
scenario, particularly when reading their description of what would be
classic clear coat pinch-off.

on another note, quality carbon's a tough reliable material. on my mtb,
i run a [LONG] 30.9mm carbon post in a 30.8mm frame by having abraded
off all the clearcoat, and then some. it's been fine for over a year,
and i have that thing up and down /all/ the time depending on terrain.
constant re-clamping, mud, etc., means it gets /way/ more abuse than any
whiny little fixed position road post.

jim beam said:

Qui si parla Campagnolo said:

Phil said:

jim beam wrote:

> [email hidden] wrote:
>
>> I stripped out my summer bike at the weekend to find a bit of
>> damage to my carbon seat post at the point where the clamp
>> compresses the post. It's a 27.2 deda post 320 in length, going
>> into an alu frame. About 18-19cm of the shaft exposed.
>>
>> When installed in a new frame I made sure there was no grease in
>> the seat tube, and even cleaned it with isoproponol, and let dry,
>> just to be safe.
>> It was slipping a bit at first, but a quarter turn of an allen
>> key on the clamp sorted that.
>> Now on inspection I seem to have crushed the pillar slightly:
>> looks like I'm going to have to replace it rather than risk a
>> breakage and nasty accident!
>>
>> Please does anyone out there have any advice on installation of a
>> carbon seat post in an alu frame? I'm a bit concerned the same
>> thing will happen again.
>> Thanks
>>
>> Henry
>>
>
> 90% probability of it being merely cosmetic. apply nail polish and
> re-fit to bike. go ride. do not use grease.

Whoohoo! Someone else who thinks that it's not that big of a deal!
--
Phil, Squid-in-Training (riding cracked/repaired frames)

Any place that attaches rider to bike, that is 'flawed', like a
potentially cracked seatpost is a bad idea to use. For somebody who
hasn't seen the mentioned seatpost, you are eager to say it's only
cosmetic. I think it is not a good idea to use carbon fiber bits that
are damaged, like hbars or seatposts.

what is "damage"? do we /know/ the op can differentiate between a
crack in the matrix and a scratch in the clearcoat? the context of
their post says "no". on that basis, the latter is by far the most
likely scenario, particularly when reading their description of what
would be classic clear coat pinch-off.

on another note, quality carbon's a tough reliable material. on my
mtb, i run a [LONG] 30.9mm carbon post in a 30.8mm frame by having
abraded off all the clearcoat, and then some. it's been fine for
over a year, and i have that thing up and down /all/ the time
depending on terrain. constant re-clamping, mud, etc., means it gets
/way/ more abuse than any whiny little fixed position road post.

I crushed a carbon section of seatpost in our shop vise (across the axis of
rotation) a couple of weeks back. It took some force to start it making
cracking noises (no visible deformation), and once I got it going, it still
took a lot of force to continue having it splinter. I was readily
impressed. An aluminum seatpost section would have begun to buckle and then
gone kaput.

However, I've heard of peoples' carbon seatposts failing not because it was
carbon, but because the epoxy bond at the clamp failed.

How many carbon failures have we read about in this NG?

FWIW, I run no carbon on my bikes, except for Campy brake levers.
--
Phil, Squid-in-Training

jim beam said:

Quoted message said:

Any place that attaches rider to bike, that is 'flawed', like a
potentially cracked seatpost is a bad idea to use. For somebody who
hasn't seen the mentioned seatpost, you are eager to say it's only
cosmetic. I think it is not a good idea to use carbon fiber bits that
are damaged, like hbars or seatposts.

what is "damage"? do we /know/ the op can differentiate between a crack
in the matrix and a scratch in the clearcoat?

I can guarantee none of us can either w/o seeing it.

the context of their post

Quoted message said:

says "no". on that basis, the latter is by far the most likely
scenario, particularly when reading their description of what would be
classic clear coat pinch-off.

Pretty weak 'basis. If the guy had called me I would lean toward
caution. I know a guy who had a seatpost break(aluminum) and it put him
in the hospital.

Quoted message said:

on another note, quality carbon's a tough reliable material. on my mtb,
i run a [LONG] 30.9mm carbon post in a 30.8mm frame by having abraded
off all the clearcoat, and then some. it's been fine for over a year,
and i have that thing up and down /all/ the time depending on terrain.
constant re-clamping, mud, etc., means it gets /way/ more abuse than any
whiny little fixed position road post.

As as I stated above, an aluminum one w/o any problem whatsoever failed
catastrophically and put the rider in the hospital. The very definition
of YMMV....

Yeah, wanna see the scar?

In article <[email hidden]>,

jim beam said:

Qui si parla Campagnolo said:

Phil said:

jim beam wrote:

>[email hidden] wrote:
>
>>I stripped out my summer bike at the weekend to find a bit of damage
>>to my carbon seat post at the point where the clamp compresses the
>>post. It's a 27.2 deda post 320 in length, going into an alu frame.
>>About 18-19cm of the shaft exposed.
>>
>>When installed in a new frame I made sure there was no grease in the
>>seat tube, and even cleaned it with isoproponol, and let dry, just to
>>be safe.
>>It was slipping a bit at first, but a quarter turn of an allen key on
>>the clamp sorted that.
>>Now on inspection I seem to have crushed the pillar slightly: looks
>>like I'm going to have to replace it rather than risk a breakage and
>>nasty accident!
>>
>>Please does anyone out there have any advice on installation of a
>>carbon seat post in an alu frame? I'm a bit concerned the same thing
>>will happen again.
>>Thanks
>>
>>Henry
>>
>
>90% probability of it being merely cosmetic. apply nail polish and
>re-fit to bike. go ride. do not use grease.

Whoohoo! Someone else who thinks that it's not that big of a deal!
--
Phil, Squid-in-Training (riding cracked/repaired frames)

Any place that attaches rider to bike, that is 'flawed', like a
potentially cracked seatpost is a bad idea to use. For somebody who
hasn't seen the mentioned seatpost, you are eager to say it's only
cosmetic. I think it is not a good idea to use carbon fiber bits that
are damaged, like hbars or seatposts.

what is "damage"? do we /know/ the op can differentiate between a crack
in the matrix and a scratch in the clearcoat? the context of their post
says "no". on that basis, the latter is by far the most likely
scenario, particularly when reading their description of what would be
classic clear coat pinch-off.

on another note, quality carbon's a tough reliable material. on my mtb,
i run a [LONG] 30.9mm carbon post in a 30.8mm frame by having abraded
off all the clearcoat, and then some. it's been fine for over a year,
and i have that thing up and down /all/ the time depending on terrain.
constant re-clamping, mud, etc., means it gets /way/ more abuse than any
whiny little fixed position road post.

From the people who warn against running a brake bolt with
cut threads.

--
Michael Press

jim beam said:

Qui si parla Campagnolo wrote:

Quoted message said:

Quoted message said:

Any place that attaches rider to bike, that is 'flawed', like a
potentially cracked seatpost is a bad idea to use. For somebody who
hasn't seen the mentioned seatpost, you are eager to say it's only
cosmetic. I think it is not a good idea to use carbon fiber bits that
are damaged, like hbars or seatposts.

what is "damage"? do we /know/ the op can differentiate between a crack
in the matrix and a scratch in the clearcoat? the context of their post
says "no". on that basis, the latter is by far the most likely
scenario, particularly when reading their description of what would be
classic clear coat pinch-off.

My philosophy is always take the conservative route (double entendre'
intended). Life is too short to be taking ANY chances with a
component that keeps you from painful, nasty injuries. There are too
many variables for me to consider recommending that the rider continue
to use the post, IMHO.

Then again, 'net advise is usually worth about what you pay for it...

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Phil said:

...
FWIW, I run no carbon on my bikes, except for Campy brake levers.

I was under the impression that squids are carbon based life forms.

--
Tom Sherman - Fox River Valley