700/23 vs 700/25 tires ?

Andrew Muzi wrote:
wrote:
Dear John,
Good heavens, more self-effacing modesty!

John Forrest Tomlinson wrote:
Dear Cowardly Carl
I'm especially not modest and I'm not especially immodest.
But I'm fairly honest and open -- far more than you. I don't hide
information about myself. You should try being more open.

wrote:
Dear John,
Please, keep telling us more about yourself and your many virtues.
You set a shining example for all of us, though perhaps not quite in
the way that you imagine.

Could you two just rent a room already?

You should have offered to sell them a tandem - never pass up a
marketing opportunity!

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

Frank Krygowski wrote:
On Mar 4, 12:44 am, Bret wrote:
On Mar 3, 5:27 pm, Tim McNamara wrote:

In article
,
Bret wrote:
If you have the physical ability
Bingo. The key to racing success. That and tactics.
I believe that there are key moments where the bike can make a
difference. Frank dodged that part of my post.

Bret, what you say is true, for certain values of "can."

IOW, sure, whether you installed your valve caps or not "can" make a
difference in certain key moments. Because you wisely chose to leave
them off, you _might_ someday outsprint your evil rival by 0.001" at
the finish. Perhaps.[...]

Or the lack of valve caps could lead to the screw cap being bumped and
loosened slightly, and then bumped leading to a slight loss of air,
which would increase the rolling resistance, causing the race to be
lost. I would feel safer throwing the letter Q in a privet bush.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

John Forrest Tomlinson wrote:
On Thu, 05 Mar 2009 20:20:04 -0600, Tim McNamara
wrote:

Of those 2000+ races, how many more did you win because of that 1%
improvement that you wouldn't have won otherwise? And how do you know
it was *that* 1% improvement?

it can't be known with certainty because races are too complex. But
if you accept that the 1% exists, the only reasonable reason not to
avail yourself of it is cost or reliabilty problems or such negatives.
It's simply stupid to say, "Well, fitness is more important, so don't
do it." Or "Bikes are the same pretty much the last 20 or 80 years"
or whatever it is.

That's the point.

Bikes have been pretty much the same since April 1, 1933.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

Frank Krygowski wrote:
[...]

OK, guys, we're throwing the bikes in the car and going on vacation.
Carry on without me.

Unless Frank's vacation is long, the argument may still be going when he
gets back.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

Tim McNamara wrote:
[...]
I wonder if the OP is even watching any more[...]

Only if he is a masochist.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

"jeffreybike" wrote:
Is there any real difference between 23mm and 25mm tires as far as
speed. Will 2mm make you that slower or faster?
thanks, Jeff

Should have skipped the thanks, since no good answer has been provided
as of yet.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

On Mar 6, 3:49*pm, John Forrest Tomlinson
wrote:
On Fri, 6 Mar 2009 07:02:29 -0800 (PST), Frank Krygowski





wrote:
I agree, that is information. *But I disagree on whether it's
information on much beyond fashion - at least, in many cases.

Over the years we've seen fashions change for racers. *For *many, many
years Campy rear derailleurs were firmly, strongly in fashion, when I
couldn't afford them. *I was using a cheap Sun Tour rear changer. *And
I recall watching guys on the expensive bikes grinding their way
through shifts, missing some on the way, when my Sun Tour crisply did
exactly what I told it to. *The difference in shifting was night and
day.

If you had gone by your standards, you'd conclude that Campy gave an
advantage over cheap Sun Tour. *You'd have been wrong.

And the reason you'd have been wrong is, partly, what I've been saying
all along. *The few guys racing on Sun Tour had a shifting advantage.
But that shifting advantage was negligible in the final outcome.
Things like power, endurance, tactics, road roughness, looking at
their watch at the wrong time, and other more important or more random
events overpowered the Sun Tour's ability to shift more quickly and
reliably.

So it's mainly fashion and so we can go back a couple decades, undoing
whatever many tiny choices in what is thought to make bikes faster and
that'll work just as well.

Baloney. *Pure baloney.

In races without depth super-talented guys might win on 1980s stuff.
In races with a lot of depth, or with very demanding conditions, the
difference woud show.

I don't think Frank is saying that new equipment is no better than
retro equipment. I think he is just comparing two pieces of retro
equipment and saying that the minor benefit of one (SunTour
derailleur) did not affect the outcome of any race.

The problem with that argument is that there is no way to know whether
it is true. A missed shift was a common excuses for a poor finish in
the '70s. The sound of grinding gears was a signal for other riders
to take off, particularly on an uphill finish. -- Jay Beattie.

On Mar 6, 5:01*pm, John Forrest Tomlinson
wrote:
On Fri, 6 Mar 2009 13:50:28 -0800 (PST), Bret
wrote:

I feel silly faulting you for lack of detail, but the Killington
Prologue course I rode started with a 1/4 mile descent, followed by
1/4 mile flat and then climbed to a finish in front of the Snowshed
lodge, not at the end of the road (Ramshead lodge) as it did in later
years. Take the hillclimb described in your linked page and slide it
1/2 mile down the road. The length is about right.

And to add some other detail, one of the road stages had fairly
significant climbing before heading up that road.

Yes, it climbed Brandon Gap. In 1987 I won that stage in the 3's by
taking a risk and attacking the last steep pitch in the big ring. It
was in the days before STI and I knew they wouldn't be able to react
immediately and they didn't. The stage doubled as the New England RR
championships and so after the race there was a frenzy of questions
trying to figure out who the first NE finisher was.


Oh, and a teammate of mine lost the overall in the masters field up
that climb by four seconds one year. *We were not happy.

The next year at the same spot, two guys tangled in front of me and we
all fell off. My second crash of the race.

Bret

On 7 Mar., 01:55, Tom Sherman
wrote:
"jeffreybike" wrote:
Is there any real difference between 23mm and 25mm tires as far as
speed. Will 2mm make you that slower or faster?
thanks, Jeff

Should have skipped the thanks, since no good answer has been provided
as of yet.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

I have been collecting arguments to support my choice of 25 mm tires
for six years, and I think I have good reasons to believe the wider
tires make me faster in the long run. There is a theoretical
advantage in less RR with the wider tire, (due to less deformation of
the rubber). German Tour Magazin has several times documented this
advantage in tests. This very small speed advantage is perhaps lost
again due to a marginally higher weight and a marginaly larger wind
resistance with the wider tire. I haven't seen that documented in
tests - but I believe the opposite factors must bring the total effect
very close to zero.
You can however clearly feel the difference in comfort, and as the
wider tire will make you more sustainable, I am personally convinced
that they make me faster by the end of the day.

On the other hand the 25 mm tires cost more - they are never on sale -
so if I calculate the short time I must work to pay for the wider
tire, the time advantage is lost again.

Although the facts leave plenty of room for your personal belief, I
think my answer to your question isn't so bad, maybe even quite
good.


Ivar of Denmark

On Fri, 6 Mar 2009 17:34:51 -0500, "Barry"
wrote:

If the climb was the access road, then it was 1.7 miles, 811 foot
rise, ~5.5% average grade with a max of 9%:
http://www.northeastcycling.com/Hill_Climbs.html

Looks like he has a mistake there, because 811 feet in 1.7 miles is an average
grade of 9%. I knew something was off because this is about the same rise but
slightly shorter than a similar climb that I know is just over 8%.

Dear Barry,

You're right--I carelessly took the figures for granted.

811/8976 = ~9%, not the 5.5% that I cited.

Something is wrong with the graph and details on that page:
http://www.northeastcycling.com/Hill_Climbs.html

The graph seems to show Killington at the 5.5% in the table, but it
also shows it as ~2.7 miles (instead of the 1.7 miles in the table),
with 811 feet of rise--which works out to the mistaken 5.5%.

It's probably just a typo somewhere, with 1.7 miles becoming 2.7 and
turning Killington into a much easier climb on paper.

And Bret has pointed out that his actual race went downhill at first,
then a bit of flat, followed by the main climb to a bit short of the
top.

But I'll settle for re-doing things as penance with the more correct
1.7 miles and 9.0% grade:

The side-by-side calculator again:
http://bikecalculator.com/veloUS.html

Plug 475.659 watts into both sides, use tubulars, on the hoods, the
correct 9.0% grade, 1.7 miles, and you should get 8.00 minutes.

watts m.sec
475.658 8.01

475.659 8.00\
476.012 8.00 --0.706 watt range for 8.00
476.365 8.00/

476.366 8.01

Add 1-lb for a water bottle at 475.659 watts, and the time drops to
8.03 minutes, 1.8 seconds less. (Same result as before.)

So yes, for that impressively unusual race (8 minutes up a hill),
carrying a useless bottle of water would probably have put you about
0.8 seconds behind the second place rider at 8:01.

That still ignores the potential aero advantage of a downtube
water-bottle.

But if you had a 0.22 mph tailwind on your run (a tiny bit more than
the bad-data 5.5% hill's 0.2 mph tailwind), you'd have carried your
water bottle up the hill in 8.00 minutes and beaten the other rider if
he climbed in still air.

Winds in Vermont often vary by more than 0.2 mph during 8-minute hill
climbs, so a rider's starting time would likely have a greater effect
than a bottle full of water.

Of course, that's all rather theoretical, but then who carries a
bottle of water up an 8-minute hill climb?

Cheers,

Carl Fogel