On Sun, 23 Jun 2019 22:17:25 -0000 (UTC), Duane
wrote:

wrote:
On Sunday, June 23, 2019 at 10:35:04 AM UTC+2, Tosspot wrote:
On 23/06/2019 03.29, John B. wrote:
On Sun, 23 Jun 2019 05:17:38 +0700, John B.
wrote:

On Fri, 21 Jun 2019 09:15:50 -0700 (PDT), Tom Kunich
wrote:

On Wednesday, June 19, 2019 at 9:49:48 AM UTC-7, duane wrote:
On 19/06/2019 10:25 a.m., jbeattie wrote:
On Tuesday, June 18, 2019 at 8:06:37 PM UTC-7, Frank
Krygowski wrote:
On 6/18/2019 1:24 PM, jbeattie wrote:
On Tuesday, June 18, 2019 at 9:49:50 AM UTC-7, Frank
Krygowski wrote:

For ordinary riding? No, most tiny improvements make no
noticeable difference. Even though we all know the
near-magic power of red paint.


What is a "tiny improvement"? The frame on my Emonda
probably weighs less than the Columbus steel forks off my
last custom racing bike. Those things were suitable for
clubbing baby harp seals or home defense. Weight and
stiffness do matter when climbing. If we're talking
about aero bits, that's harder call -- except that dopes
on aero bars riding in packs can result in a massive
worsening of your riding experience. Wearing aero shoe
covers may keep your feet warmer on chilly mornings,
which might make you faster. It all adds up.

Stiffness probably does not make a detectable difference,
unless the frame is so flexible that things are scraping.
Remember the discussion we had about the bike magazine's
test of modern stiff CF frames vs. older, heavier steel
frames? The test riders gushed about how the stiffness
improved their climbing, but the math showed the speed
difference was precisely what would be predicted by the
weight difference.

Weight matters when climbing. If getting to the top of the
hill before your buddy is really, really important, a
lighter bike will help by whatever the percent difference
in total bike+rider weight. If a 160 pound rider changes
his 20 pound bike for an 18 pound bike, he should be about
1% faster up a steep hill. Whoopee!

Make that a 5lb weight difference. You need to borrow a
well-fitting modern 15lb racing bike with an appropriate gear
range and then do a long ride with lots of hills. It's not a
subtle or imagined difference compared to a T1000 or
old-school steel sport touring bike, particularly if you're
trying to keep up with others.

-- Jay Beattie.


5lbs? My Tarmac is probably closer to 12 lbs lighter than my
cro moly Volpe.

And no in reality it's not a subtle or imagined difference.
And no, it's not just about weight unless everything else is
exactly the same.

I changed my Look pedals from CX 6 cyclocross pedals which are
very easy to get into and put 206's on which were much lighter.
Then since I had those 50 mm deep clinchers just sitting there I
installed those The "out-the-door" weight was 21.7 lbs. for the
Pinarello. I'm pulling my Basso apart to refinish it and I have
another set of cheap Chinese tubeless wheels that I'll install
when it get's back together. Also I think that my 44 mm bars are
too wide so will reduce this to 42 mm. Chinese carbon bars as
well. I think that I can keep a steel bike and have it about the
same weight as the Colnago. Granted that the Colnago is not an
ultra-light but my friend is touring Italy and he went to a bike
factory and they advised him against buying carbon. They said
that they support a racing team with these ultra-lights but that
they are replaced every single race. They say that there's no way
that you can get any reliability out of a piece of cloth that
tears with resin on it that cracks.

That last is a rather strange statement given that practically all
modern recreation and work boats are made from a mixture of cloth
and resin. Do you mean that my 15 year old, 40 ft sloop, that had
sailed across the pacific ocean and that I sailed from Thailand to
Australia and back was prone to crack?

Or is this just another of your poorly thought out and wild eyed
statements.


As an addendum to the above I found a site that had tested a number
of carbon composite samples. The average of 4 separate test samples
was 982.5 MPa or 142,499psi. In comparison the ultimate tensile
strength of "mild steel" (Aisi 1018) is 440 MPa or 63,816 psi.
http://www.scielo.br/scielo.php?scri...92006000100016


https://www.azom.com/article.aspx?ArticleID=6115

As an aside, the carbon composite samples appeared to show no
elongation before fracturing during the tensile strength testing
while the mild steel specifications show a 15% elongation before
failure. Also the tensile strength necessary to produce elongation of
the mild steel is 370 MPa. Which illustrates a major difference
between carbon composite and steel. The steel bends or elongates
prior to complete failure while the carbon just breaks.

Which is what makes CF frames incredibly rigid. They are fun to ride
because you feel that every erg on the pedal converts to KE without
loss. I've never owned one so can't comment on the 'rough ride'
criticism, but I could believe it.


When do the old farts learn to understand that the properties of CF
depends on the direction. Today CF frames are one of most comfortable frames.

Lou


I mentioned that once and got blasted by a bunch of people here. I doubt
any had ridden a decent CF road bike. So I stopped paying attention to
their posts.

Although I have to admit that the age of old farts seems to be a moving
target.

Well, Yes! After all , as the song would have it "another day older
(and deeper in debt)".
--
cheers,

John B.