carbon seat stays - do they really make much difference?

Thanks for the reply Arthur.

I suppose it comes down to quality of tubing more than material. I
would hope that a frame built from deda sc610 would give a pretty
compliant ride.

I was thinking that carbon seat stays might just be a bit of a gimmick
in terms of damping. However, considering that I would not entertain
riding an aluminium fork rather than a carbon one for those exact same
reasons seems a bit contradictory.

The thing that worries me about carbon on the mainframe is the
potential lifespan. I read somewhere that carbon forks should be
replaced fairly regularly to avoid fatigue problems. Does the same
apply to carbon rear ends/ stays and can that actually be done
(replacing the carbon stays on a frame), or does the frame become
obsolete?

Is a pure aluminium frame actually any more durable/ longer life span
than aluminium/ carbon combo?


--
darrenf

darrenf wrote:
snip
I was thinking that carbon seat stays might just be a bit of a
gimmick
in terms of damping. However, considering that I would not entertain
riding an aluminium fork rather than a carbon one for those exact
same
reasons seems a bit contradictory.
snip

Hi there.

Emperor's new seat stays!

I'm sure that carbon rear-ends only make a difference to the marketing
department, whereas carbon forks do make a real difference to the ride
of a bike.

Front fork comfort is due to the vibration-absorbing properties of the
fork, which comes from the horizontal compliance. i.e. the fork bends
slightly back and forwards in response to the shocks transmitted by the
hub. Carbon materials are gonna help with this.

To get the same effect at the rear of the bike, then there would have
to be some sort of vertical compliance from the whole rear triangle. I
don't think you're going to get a significant amount of movement here
without seriously reducing the stiffness of the frame.

A nice long carbon seat pin (on a compact frame) would be a far better
bet for damping the (your) rear end, as this works the same way as the
front fork.

Of course, all that is just my opinion... I'm not some sort of
anti-carbon luddite, as I ride a full carbon frame/forks. It's just
that if you're going to drop serious money on a frame I'd rather invest
in technology, not marketing.

Cheers, Andy

ps Arthur - I don't think you're going to get an unbiased view from
someone who's chosen to spend circa =A31000 on a new frame. Of course
they're going to tell you it makes a difference.

wrote:

: ps Arthur - I don't think you're going to get an unbiased view from
: someone who's chosen to spend circa £1000 on a new frame. Of course
: they're going to tell you it makes a difference.

Very true. Of course, I'm completely unbaised about the virtues of
expensive Ti frames

--
Arthur Clune PGP/GPG Key: http://www.clune.org/pubkey.txt
It is better to light a candle than to curse the darkness

darrenf wrote:

: The thing that worries me about carbon on the mainframe is the
: potential lifespan. I read somewhere that carbon forks should be
: replaced fairly regularly to avoid fatigue problems.

I'm not totally convinced that carbon forks need replacing more
often that every 10 years or so. But then, I won't ride carbon
steered forks or handlebars.

Carbon is wonderful, but clamping round a carbon tube isn't a
good use IMO. I know the bung in a carbon steerer should resist
the crushing force, but..

a) That relies on it being installed properly and
b) Handlebars and seat posts don't have anything to resist the crushing
force.

I don't want a bike that has to be built up with a torque wrench personally.
I find it telling that Trek, who are one of the more experienced with carbon
out there, make their top of the line fork with an Al steerer.

Rant over

Arthur

--
Arthur Clune PGP/GPG Key: http://www.clune.org/pubkey.txt
It is better to light a candle than to curse the darkness