Cutting a carbon handlebar

[Chris Nelson]

A friend of mine is giving me an Easton EC90 carbon mtb handlebar. It
hasn't been used but is slightly damaged at one end because he tried to
put bar ends on it before knowing that you can't for that model.
Anyways, its useless to him because he insists on barends and ended up
buying another bar. The bar is a 23" and my bar is 22", so I was
thinking of taking the bar and cutting a half inch off of each side and
swapping them since it would amount to a free upgrade. He said the
damaged part was less than a half an inch so it should workout. My
current bar is fine but is one that would be found in the economy bin.
Is it OK to cut a carbon bar, assuming I don't screw it up with a
masking tape hack saw approach? I googled this and found something
about moving the location of the brake clamps and shifters to a
location on the bar that wasn't as strong, but it seems that shifters
and brake clamps location would vary from brand to brand anyway?

Any insight would be appreciated. Sarcasm is OK too, but should be of
fine quality.

Chris

 

[spin156]

Chris Nelson wrote:
> A friend of mine is giving me an Easton EC90 carbon mtb handlebar. It
> hasn't been used but is slightly damaged at one end because he tried to
> put bar ends on it before knowing that you can't for that model.
> Anyways, its useless to him because he insists on barends and ended up
> buying another bar. The bar is a 23" and my bar is 22", so I was
> thinking of taking the bar and cutting a half inch off of each side and
> swapping them since it would amount to a free upgrade. He said the
> damaged part was less than a half an inch so it should workout. My
> current bar is fine but is one that would be found in the economy bin.
> Is it OK to cut a carbon bar, assuming I don't screw it up with a
> masking tape hack saw approach? I googled this and found something
> about moving the location of the brake clamps and shifters to a
> location on the bar that wasn't as strong, but it seems that shifters
> and brake clamps location would vary from brand to brand anyway?
>
> Any insight would be appreciated. Sarcasm is OK too, but should be of
> fine quality.
>
> Chris

Here's an article, from Easton, that covers your question:

http://www.eastonbike.com/downloadable_files/r&d_files/R&D-05-Carbon.pdf

Make sure you wear a mask and use good ventilation. Important.

 

[Phil, Squid-in-Training]

Chris Nelson wrote:
> A friend of mine is giving me an Easton EC90 carbon mtb handlebar. It
> hasn't been used but is slightly damaged at one end because he tried
> to put bar ends on it before knowing that you can't for that model.
> Anyways, its useless to him because he insists on barends and ended up
> buying another bar. The bar is a 23" and my bar is 22", so I was
> thinking of taking the bar and cutting a half inch off of each side
> and swapping them since it would amount to a free upgrade. He said the
> damaged part was less than a half an inch so it should workout. My
> current bar is fine but is one that would be found in the economy bin.
> Is it OK to cut a carbon bar, assuming I don't screw it up with a
> masking tape hack saw approach? I googled this and found something
> about moving the location of the brake clamps and shifters to a
> location on the bar that wasn't as strong, but it seems that shifters
> and brake clamps location would vary from brand to brand anyway?
>
> Any insight would be appreciated. Sarcasm is OK too, but should be of
> fine quality.

The crushed end of the bar may have compromised the integrity of the bar
further in, invisibly delaminating, causing crack propogation that may
result in catastrophic failure during a hard downhill run, causing failure
of the handlebar and subsequent personal injury and possibly death.

I'd ride it anyways.

--
Phil, Squid-in-Training

 

[RonSonic]

On Sun, 12 Feb 2006 20:38:38 -0500, "Phil, Squid-in-Training"
<[email protected]> wrote:

>Chris Nelson wrote:
>> A friend of mine is giving me an Easton EC90 carbon mtb handlebar. It
>> hasn't been used but is slightly damaged at one end because he tried
>> to put bar ends on it before knowing that you can't for that model.
>> Anyways, its useless to him because he insists on barends and ended up
>> buying another bar. The bar is a 23" and my bar is 22", so I was
>> thinking of taking the bar and cutting a half inch off of each side
>> and swapping them since it would amount to a free upgrade. He said the
>> damaged part was less than a half an inch so it should workout. My
>> current bar is fine but is one that would be found in the economy bin.
>> Is it OK to cut a carbon bar, assuming I don't screw it up with a
>> masking tape hack saw approach? I googled this and found something
>> about moving the location of the brake clamps and shifters to a
>> location on the bar that wasn't as strong, but it seems that shifters
>> and brake clamps location would vary from brand to brand anyway?
>>
>> Any insight would be appreciated. Sarcasm is OK too, but should be of
>> fine quality.
>
>The crushed end of the bar may have compromised the integrity of the bar
>further in, invisibly delaminating, causing crack propogation that may
>result in catastrophic failure during a hard downhill run, causing failure
>of the handlebar and subsequent personal injury and possibly death.
>
>I'd ride it anyways.

Yeah, me too. But for the first few rides i'd alert on any noise from the front
of the bike.

Ron

 

[Simon Cooper]

"Chris Nelson" <[email protected]> wrote in message
news:[email protected]...
> Is it OK to cut a carbon bar, assuming I don't screw it up with a
> masking tape hack saw approach?
>
> Any insight would be appreciated. Sarcasm is OK too, but should be of
> fine quality.

My experience is rather more with carbon kayak paddle shafts, which are
supplied as a given length then cut as required. At the time I last did it,
I was at college with access to the aeronautical eng. machine shop with a
diamond cutting wheel, but I'm pretty sure I did a home job about 13 years
ago without.

I'd therefore say it'd be just fine to cut it down. But don't expect any
warning of failure, it's brittle stuff.

 

[Chris Nelson]

Phil wrote about carbon fiber "invisibly delaminating"

Simon Cooper wrote "But don't expect any warning of failure, it's
brittle stuff."

Sounds like a lousy material to make bicycles out of if there is no
conclusive way to qualify the stuff for riding.

 

[Zog The Undeniable]

Chris Nelson wrote:

> Phil wrote about carbon fiber "invisibly delaminating"
>
> Simon Cooper wrote "But don't expect any warning of failure, it's
> brittle stuff."
>
> Sounds like a lousy material to make bicycles out of if there is no
> conclusive way to qualify the stuff for riding.
>
But it's a good way to get consumers to pay $$$ for plastic bikes.

 

[Simon Cooper]

"Zog The Undeniable" <[email protected]> wrote in message
news:43f0d346.0@entanet...
> Chris Nelson wrote:
>
> > Phil wrote about carbon fiber "invisibly delaminating"
> >
> > Simon Cooper wrote "But don't expect any warning of failure, it's
> > brittle stuff."
> >
> > Sounds like a lousy material to make bicycles out of if there is no
> > conclusive way to qualify the stuff for riding.
> >
> But it's a good way to get consumers to pay $$$ for plastic bikes.

It's quite possible to check the material out, but most people don't have an
ultrasonic or x-ray based bit of testing kit around...

I also don't doubt that anyone still in business is adequately
over-engineering their wares for public use. If it does start to
delaminate, it should start to get more flexible. Maybe you'd detect it...
At the end of the day, that situation isn't so different than the way
aluminium cranks fail after cracking first (that site of Jobst's has a good
description). But well made carbon shouldn't spontaneously delaminate.