Carbon rims melting

Anyone here ever actually melted a carbon rim from braking?

In light of the nature of the material (specifically the resin) it
does not surprise me that it CAN happen, but until a friend described
it happening to him, I don't believe I have previously heard of it
happening.
Has anyone experienced this or know someone who has?

DR

On Oct 10, 10:12*pm, DirtRoadie wrote:
Anyone here ever actually melted a carbon rim from braking?

In light of the nature of the material (specifically the resin) it
does not surprise me that it CAN happen, but until a friend described
it happening to him, I don't believe I have previously heard of it
happening.
Has anyone experienced this or know someone who has?

DR

Yes, I have one.

Brakes can get hot, and can be often or never a problem; obviously
depending on terrain, rider weight, probably other factors.

Once the resin breaks down the rim surface can distort into odd
surface ripples (shape depends on layup I guess). I've seen other rims
do this too. Usually asian made; US-made rims seem to use better
resin...?

Another reason to stick with aluminum brake tracks IMHO.

On Oct 10, 10:12*pm, DirtRoadie wrote:
Anyone here ever actually melted a carbon rim from braking?

In light of the nature of the material (specifically the resin) it
does not surprise me that it CAN happen, but until a friend described
it happening to him, I don't believe I have previously heard of it
happening.
Has anyone experienced this or know someone who has?


I thought that all crabno fribe (at least as used in bicycles)
was a thermo-set resin. I know it isn't strictly applicable
but there are such things as graphite &/or carbon brake
rotors for certain racing and "end-of-flight" applications
which have to handle 600C*, which should be at least
one or two Kelvins more than a bicycle would see outside
of an atomic hydrogen torch. So, the upshot being that
if it did [melt] it seems like a crap bit to start with.

* to say nothing of the scores of Newtons or Dynes or
Ergs or SOMEThings

In article
,
DirtRoadie wrote:

Anyone here ever actually melted a carbon rim from braking?

In light of the nature of the material (specifically the resin) it
does not surprise me that it CAN happen, but until a friend described
it happening to him, I don't believe I have previously heard of it
happening.
Has anyone experienced this or know someone who has?

Cross linked polymers do not melt.

--
Michael Press

Michael Press wrote:
:In article
,
: DirtRoadie wrote:

: Anyone here ever actually melted a carbon rim from braking?
:
: In light of the nature of the material (specifically the resin) it
: does not surprise me that it CAN happen, but until a friend described
: it happening to him, I don't believe I have previously heard of it
: happening.
: Has anyone experienced this or know someone who has?

:Cross linked polymers do not melt.

Really? Styroflex and Hytrel don't really exist? BASF and DuPont
have been feeding us all hallucengens to keep us buying their
non-existent products?

--
sig 85

On Oct 11, 7:16*pm, David Scheidt wrote:
Michael Press wrote:

:In article
,

: DirtRoadie wrote:

: Anyone here ever actually melted a carbon rim from braking?
:
: In light of the nature of the material (specifically the resin) it
: does not surprise me that it CAN happen, but until a friend described
: it happening to him, I don't believe I have previously heard of it
: happening.
: Has anyone experienced this or know someone who has?

:Cross linked polymers do not melt.

Really? *Styroflex and Hytrel don't really exist?

I don't know about cross-linked, but a quick search indicates
that those are both thermoplastics. I have no idea why they
would be used in a high temperature application, but you may
spec your bicycle as you wish.

Norman wrote:
:On Oct 11, 7:16*pm, David Scheidt wrote:
: Michael Press wrote:
:
: :In article
: ,
:
: : DirtRoadie wrote:
:
: : Anyone here ever actually melted a carbon rim from braking?
: :
: : In light of the nature of the material (specifically the resin) it
: : does not surprise me that it CAN happen, but until a friend described
: : it happening to him, I don't believe I have previously heard of it
: : happening.
: : Has anyone experienced this or know someone who has?
:
: :Cross linked polymers do not melt.
:
: Really? *Styroflex and Hytrel don't really exist?

:I don't know about cross-linked, but a quick search indicates
:that those are both thermoplastics. I have no idea why they

They're thermoplastic elstamoers, which have the characteristic of
being cross-linked polymers that melt, which Mr Press doesn't think
exist.

:would be used in a high temperature application, but you may
:spec your bicycle as you wish.

Well, you wouldn't, but that wasn't the question. But I'm pretty sure
I've seen grips made of hytrel.

--
sig 4

On Oct 11, 5:07*pm, Michael Press wrote:
In article
,


Cross linked polymers do not melt.

That is a VERY broad statement. Can you provide an example?
I believe there may be some examples of some heat resistant materials
that vaporize before melting. But how about a link to a data sheet for
some specific material? And will you concede that the statement is
inaccurate if we can come up with ONE counterexample? Doesn't cross-
linked polyethylene qualify?

I agree that carbon fiber itself is amazingly heat resistant.

DR

In article ,
David Scheidt wrote:

Michael Press wrote:
:In article
,
: DirtRoadie wrote:

: Anyone here ever actually melted a carbon rim from braking?
:
: In light of the nature of the material (specifically the resin) it
: does not surprise me that it CAN happen, but until a friend described
: it happening to him, I don't believe I have previously heard of it
: happening.
: Has anyone experienced this or know someone who has?

:Cross linked polymers do not melt.

Really? Styroflex and Hytrel don't really exist? BASF and DuPont
have been feeding us all hallucengens to keep us buying their
non-existent products?

I do not understand the question. Let me make myself clear.
Cross linked polymers do not melt.

--
Michael Press

Michael Press wrote:
:In article ,
: David Scheidt wrote:

: Michael Press wrote:
: :In article
: ,
: : DirtRoadie wrote:
:
: : Anyone here ever actually melted a carbon rim from braking?
: :
: : In light of the nature of the material (specifically the resin) it
: : does not surprise me that it CAN happen, but until a friend described
: : it happening to him, I don't believe I have previously heard of it
: : happening.
: : Has anyone experienced this or know someone who has?
:
: :Cross linked polymers do not melt.
:
: Really? Styroflex and Hytrel don't really exist? BASF and DuPont
: have been feeding us all hallucengens to keep us buying their
: non-existent products?

:I do not understand the question. Let me make myself clear.
:Cross linked polymers do not melt.

You deny the existence of Stryoflex and Hytrel?

--
sig 109