On 6/19/2019 4:52 PM, Sir Ridesalot wrote:
On Wednesday, June 19, 2019 at 2:18:52 PM UTC-4, Frank Krygowski wrote:
On 6/19/2019 10:25 AM, 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.

Again, I'm not saying the weight doesn't make a difference! The
difference it makes on an uphill is the percentage difference in
bike+rider weight.

Does nobody remember the discussion a couple years ago where the
magazine article's data proved that? They put young racers on modern CF
bikes, then on 1980s steel racing bikes and timed them up long hills.
The speed difference was exactly what the weight difference predicted.

Think about changing to a bike that was five pounds lighter, but then
strapped a five pound weight around your waist. Hopefully people here
wouldn't think you'd still be way faster up the hills, right?

And again, the stiffness, the snappiness, the magical handling of a CF
bike made no difference at all in that comparison test. There were other
details the youngsters liked on the new bikes - as in "I was afraid to
take my hands off the hoods to shift" - but the speed difference was
apparently due to the weight.

If others think there's some other energy savings or power increase,
please explain it in engineering or scientific terms. Explain how it's
not magic.

--
- Frank Krygowski

Weight doesn't make a difference? News to me.

In 1984 I bought a MIELE BETA bicycle with Tange double-butted tubing and with a complete Shimano 600 groupset. A year or two later I bought a MIELE EQUIPE PRO with a Columbus SL frameset and with a complete Dura Ace groupset. Compared to the Beta the Equipe Pro climbed like a homesick angel, accelerated easier and in general took less energy to keep moving. I imagine that the difference a five to ten pounds lighter carbon fiber bicycle would be even more noticeable.

Sir, please read more carefully. Here's what I typed above:
"I'm not saying weight does not make a difference!"

What I'm doing is quantifying the difference. The math isn't hard.


--
- Frank Krygowski