DANGER - CARBON FIBER FRAMES

On Sat, 27 Aug 2016 16:00:26 -0700 (PDT), Phil
wrote:

On Tuesday, August 23, 2016 at 3:55:06 PM UTC-7, John B. wrote:
On Mon, 22 Aug 2016 22:26:38 -0400, Frank Krygowski
wrote:

On 8/22/2016 6:11 PM, wrote:

I didn't say "junk", I said pretty bad. It was soft so that the heavy tubing wouldn't be too stiff to ride on the horrible Italian roads...

Keep in mind that for the material itself, soft (vs. hard) is an
entirely different property than stiffness.

The stiffness of a metal is measured by its modulus of elasticity (AKA
elastic modulus), and any steel used in a bike frame will have the same
stiffness, within a few percent.

Now the stiffness of a frame is another matter; but it's influenced by a
lot of design decisions. The frame material is only one of those factors.

There was an article in one of the bike magazines, maybe Bicycle
Quarterly, about some bloke that had two bikes built, a pink one with
super deluxe, wonderful, wonderful, tubes and a blue one with mundane
old, regular, tubes.

They then got a bunch of "experts" out to ride and evaluate the
frames. There was no consistence between decisions over which was the
"best frame" and a substantial number of "experts" though the low end
frame rode better.
--
cheers,

John B.

It was Bicycle guide and it was way more involved than that. they had several bikes built with everything from straight 4130 to exotic sets. Identical size and paint and as I remember they blindfolded the rider when he got on.
the bike they liked the best was the 4130.
Phil Brown

Bicycle guide may well have done it also but the article I remember
specifically stated two bike frames were made at the same time, by the
same frame maker, to the same measurements, from two different grades
of tubes and painted two different colors.

I will try to find the article.
--
cheers,

John B.

On 8/27/2016 6:00 PM, Phil wrote:
On Tuesday, August 23, 2016 at 3:55:06 PM UTC-7, John B. wrote:
On Mon, 22 Aug 2016 22:26:38 -0400, Frank Krygowski
wrote:

On 8/22/2016 6:11 PM, wrote:

I didn't say "junk", I said pretty bad. It was soft so that the heavy tubing wouldn't be too stiff to ride on the horrible Italian roads...

Keep in mind that for the material itself, soft (vs. hard) is an
entirely different property than stiffness.

The stiffness of a metal is measured by its modulus of elasticity (AKA
elastic modulus), and any steel used in a bike frame will have the same
stiffness, within a few percent.

Now the stiffness of a frame is another matter; but it's influenced by a
lot of design decisions. The frame material is only one of those factors.

There was an article in one of the bike magazines, maybe Bicycle
Quarterly, about some bloke that had two bikes built, a pink one with
super deluxe, wonderful, wonderful, tubes and a blue one with mundane
old, regular, tubes.

They then got a bunch of "experts" out to ride and evaluate the
frames. There was no consistence between decisions over which was the
"best frame" and a substantial number of "experts" though the low end
frame rode better.
--
cheers,

John B.

It was Bicycle guide and it was way more involved than that. they had several bikes built with everything from straight 4130 to exotic sets. Identical size and paint and as I remember they blindfolded the rider when he got on.
the bike they liked the best was the 4130.
Phil Brown


Right, same builder, same finish, multiple riders.

IIRC the Columbus Thron bike was deemed 'pick of the litter'

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 25/08/16 06:09, Frank Krygowski wrote:
On 8/24/2016 3:40 PM, sms wrote:
On 8/22/2016 6:17 PM, jbeattie wrote:

snip

Not to feed the frenzy, but CF forks are on bikes of every stripe and
in practically every price range. Old Lardy is probably getting CF
forks on his mid-fi urban bike.

It's a big marketing advantage to be able to use the words "Carbon
Fiber" in the description of a bicycle, and if they have to have only
one CF part, the fork is what makes sense I guess. More sense than a
seat post.

Um... why not the seatpost?



Weight saving.

--
JS

On Friday, August 26, 2016 at 1:14:31 PM UTC-7, Frank Krygowski wrote:
On 8/26/2016 3:53 PM, jbeattie wrote:

For John B, although staying dry and keeping the bike a little cleaner are good reasons for owning fenders, for training in the rain, they are basically a social requirement around here. People who show up for group rain-rides in PDX without fenders are pariahs, and in fact, I was ostracized for not have a long enough flap. So, I now have a longer fender flap on my Roubaix fenders.

One of our newer club riders was mentioning that yesterday. Apparently
he'd spent some time living in either Portland or Seattle.

We got caught by a thunderstorm on a ride last week. As usual, I was
the only one with fenders. One woman, drafting me, complained good
naturedly that a bit of road spray was bypassing my fenders. I pointed
out that I couldn't ride within 15 feet of her husband because of the
rooster tail spewed by his bike!

--

- Frank Krygowski

Frank, in Seattle or Portland you aren't "caught" by thunderstorms or showers or heavy rain - you're "caught" by sunshine.