John B. Slocomb writes:

On Tue, 18 Jun 2019 12:46:55 -0400, Frank Krygowski
wrote:

On 6/18/2019 3:11 AM, wrote:
On Monday, June 17, 2019 at 11:57:10 AM UTC-5, Tom Kunich wrote:
OK, I just went out and weighed my road bikes again. Just like I would walk out the door with.

Basso Loto - this is the final year of production and used Basso
Tubing Concepts tubes instead of Columbus tubes. 22.12 lbs

Time VX - 28 mm tires and aluminum BB lugs and multi-shaped carbon tubes. - 21.9 lbs

Colnago CLX 3.0 - carbon wheels and everything else possible. 20.17 lbs.

Now it seems pretty plain that I could reduce the weight of the
Basso to very close to that of the Colnago. But to do so would
mean I would have to put carbon wheels on it. And maybe a carbon
fork which would put me in a position of having a hybrid
carbon/steel bike which seems to kill the idea of having a steel
bike in the first place.

The real question is does this weight really make a difference?

A 22 lb bike and a 190 lb lard-assed rider makes that 2 lb
difference only 0.01% difference in weight


190+22.12=212.12
190+20.17=210.17
Difference = 1.95 lbs
1.95 divided by 212.12 = .009193
Converting to percentage, which means moving the decimal point two
places to the right, equals 0.92% if rounding to two decimal points
for percentages. A little less than 1%. Yet, you write "0.01%".
I will not ask what grades you received in basic math classes
during your elementary school education. But it might help your so
called argument if you used correct math skills.

Now, does 1% make any difference? In the 2019 Giro d'Italia the
final stage was a 17 kilometer time trial. The winning time was 22
minutes, 7 seconds. Second place was 22 minutes, 11 seconds. A
difference of 4 seconds. 4 seconds is 0.30% of the winning time.
Less than one third of one percent. Or three tenths of one
percent.

The winner of the Giro d'Italia 2019 won in 90 hours, 1 minute, 47
seconds total time. Second place was 1 minute, 5 seconds behind.
1 minute, 5 seconds, is 0.02% of the total winning time. Much,
much, much less than 1%. Its one fiftieth of one percent.

Does 1% weight difference matter? Maybe that 1% weight difference
is equal to one fiftieth of one percent difference in time. Maybe.

When comparing weight (or aero) difference percentages, I don't think
it's realistic to transform them into racing elapsed time percentages,
for at least two reasons.

First, the speed vs. power curve is very non-linear, especially at
racing speeds. It's a cubic function. So producing (say) 2% more power
(or saving 2% of one's power by not having to move a heavier bike) will
not increase one's speed by 2%. The speed benefit will be less.

Second, in any race but a time trial, there is a _lot_ of stuff going on
that will mask the tiny differences we're talking about. Case in point:
I mentioned a club ride last week where I drafted a strong rider and so
finished five minutes or more ahead of everyone other than that strong
rider. The drafting was the benefit. It completely masked the fact that
I was on a 26 pound touring bike with added bags and fenders, 5 cogs in
back, toe clips, friction shifters, etc.

In a road race, there's drafting, choosing lines through corners,
guessing when to jump and when to let go, getting boxed in or not
getting boxed in, avoiding patches of bad pavement, getting enough sleep
the night before, and much much more. I think the effect of any design
feature of the bike is almost always lost in the noise.

And if someone's not racing? To me, finishing a "training" ride or a
recreational ride ten seconds earlier is of no value whatsoever. In
fact, if my fenders or handlebar bag make me finish five minutes later,
they're still a net benefit.

True, but how else would one measure the effect of a lighter weight
bicycle?

Easier to carry upstairs.