700/23 vs 700/25 tires ?

wrote in message
...
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

There are rather few tires which are offered in identical models and in
these two sizes. With the larger tire may be a plus in comfort, perhaps
rolling resistance, but these will be not the ones typically compared. A
Vittoria Rubino Pro 25 can be just as commonly compared to a 23 of the same
model, but may not compare positively to a Vittoria EVO-KX of the same size
with regard to the same elements noted.

In addition, the nominal sizes. which vary by manufacturer, don't correspond
to theoretical measurements, but to real ones.

Of you take Frankie's advice, whatever plus you may experience, you will
likely suffer greater disadvantages. If you don't believe that, just ask
Frankie, who wrote that above many times, many messages ago. According to
him, or the contrapositive of his logical suggestion, you would look for a
tire that is less good, then on the opposite side, you get a level of
advantage that outweighs the negatives you purchased.

--
Sandy
Verneuil-sur-Seine, FR

In article ,
wrote:

On Fri, 6 Mar 2009 12:26:43 -0800 (PST), Bret
wrote:

Now that I think about it. That second picture is from a hillclimb TT
(Cat 3 Killington Prologue) where I won by 1 sec in a race that lasted
slightly under eight minutes. That's a .2% margin. If I had carried a
water bottle I probably wouldn't have won.

Bret

Dear Bret,

Heck, if you'd had a different starting time up the hill, you might
not have won.

Sometimes it's easy to get lost in the details.

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

To get an idea of what's involved, have some fun with this
side-by-side calculator:
http://bikecalculator.com/veloUS.html

Plug 315.722 watts into both sides, use tubulars, on the hoods, 5.5%
grade, 1.7 miles, and you should get 8.00 minutes.

Raise the power by a hundredth of a watt to 315.723, and the time
drops to 7.99 minutes.

Lower the power by 0.506 watts to 315.216 watts and the time rises to
8.01 minutes.

Add 1-lb for a water bottle at 315.722 watts, and the speed drops to
8.03 minutes, 1.8 seconds less.

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.

It's not that weird. I once competed in a hill climb that took me 12
minutes. I missed the podium by less than 3/10ths of a second. I spent a
lot of time thinking about those 3/10ths.

http://wiredcola.com/content/my-first-timetrial

Here's a race that is contested by some of the top riders on this
continent. The first stage is a 700m hill climb:

http://www.tourdewhiterock.ca/race_details.php

The Tour de Delta, generally contested by the same riders, more or less,
starts with a 3km (flat) prologue:

http://www.tourdedelta.com/theRace.html#

Of course, that's only if we ignore the potential aero advantage of a
downtube water-bottle.

But if you had a 0.2 mph tailwind on your run, you'd have carried your
water bottle up the hill in the same 8.00 minutes and beaten the other
rider if he climbed in still air by the same 1-second margin.

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.

The goal, then, is to make sure your performance margin is greater than
wind variance. But if you can't have that, at least do everything else
right. You might just win, and the marginal effort of getting a lot of
these choices right is . . . negligible?

--
Ryan Cousineau http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

In article ,
Tom Sherman wrote:

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, I swear the moment I read that, the theme song from "The Odd
Couple" played in my head.

--
Ryan Cousineau http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

On Fri, 6 Mar 2009 13:50:28 -0800 (PST), Bret
wrote:

On Mar 6, 2:21*pm, wrote:
On Fri, 6 Mar 2009 12:26:43 -0800 (PST), Bret
wrote:

Now that I think about it. That second picture is from a hillclimb TT
(Cat 3 Killington Prologue) where I won by 1 sec in a race that lasted
slightly under eight minutes. That's a .2% margin. If I had carried a
water bottle I probably wouldn't have won.

Bret

Dear Bret,

Heck, if you'd had a different starting time up the hill, you might
not have won.

Sometimes it's easy to get lost in the details.

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

To get an idea of what's involved, have some fun with this
side-by-side calculator:
*http://bikecalculator.com/veloUS.html

Plug 315.722 watts into both sides, use tubulars, on the hoods, 5.5%
grade, 1.7 miles, and you should get 8.00 minutes.

Raise the power by a hundredth of a watt to 315.723, and the time
drops to 7.99 minutes.

Lower the power by 0.506 watts to 315.216 watts and the time rises to
8.01 minutes.

Add 1-lb for a water bottle at 315.722 watts, and the speed drops to
8.03 minutes, 1.8 seconds less.

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.

Of course, that's only if we ignore the potential aero advantage of a
downtube water-bottle.

But if you had a 0.2 mph tailwind on your run, you'd have carried your
water bottle up the hill in the same 8.00 minutes and beaten the other
rider if he climbed in still air by the same 1-second margin.

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

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.

Bret

Dear Bret,

Nah, there's nothing silly about correcting my mistaken assumption. I
appreciate your good-natured response.

Barry pointed out a much bigger problem, namely that the page that I
relied on is simply wrong about the grade--probably someone made a
typo and calculated a 5.5% grade for 2.7 miles and 811 feet of rise
instead of the steeper 1.7 miles and 811 feet of rise.

As penance, I just re-did things with the corect ~9.0% grade in a
reply to Barry.

I worked with a 1.7 mile stead climb at 9% instead of trying to guess
the 1/4 mile flat, 1/4 mile downhill details. After all, including
flats and downhills would only lessen the already tiny disadvantage of
a 1-lb water-bottle, which comes out on climbs.

Reassuringly, a ~0.2 mph tailwind advantage over anyone starting up
the hill at a different time will still let you win while carrying a a
full water-bottle.

As a sidelight, ~0.2 mph is ~0.3 feet per second, a bit less than four
inches. Spread your thumb and forefinger while saying one-thousand-one
and you have a fair idea of how tiny that wind difference is.

Cheers,

Carl Fogel

On Sat, 07 Mar 2009 03:13:16 GMT, Ryan Cousineau
wrote:

In article ,
wrote:

On Fri, 6 Mar 2009 12:26:43 -0800 (PST), Bret
wrote:

Now that I think about it. That second picture is from a hillclimb TT
(Cat 3 Killington Prologue) where I won by 1 sec in a race that lasted
slightly under eight minutes. That's a .2% margin. If I had carried a
water bottle I probably wouldn't have won.

Bret

Dear Bret,

Heck, if you'd had a different starting time up the hill, you might
not have won.

Sometimes it's easy to get lost in the details.

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

To get an idea of what's involved, have some fun with this
side-by-side calculator:
http://bikecalculator.com/veloUS.html

Plug 315.722 watts into both sides, use tubulars, on the hoods, 5.5%
grade, 1.7 miles, and you should get 8.00 minutes.

Raise the power by a hundredth of a watt to 315.723, and the time
drops to 7.99 minutes.

Lower the power by 0.506 watts to 315.216 watts and the time rises to
8.01 minutes.

Add 1-lb for a water bottle at 315.722 watts, and the speed drops to
8.03 minutes, 1.8 seconds less.

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.

It's not that weird. I once competed in a hill climb that took me 12
minutes. I missed the podium by less than 3/10ths of a second. I spent a
lot of time thinking about those 3/10ths.

http://wiredcola.com/content/my-first-timetrial

Here's a race that is contested by some of the top riders on this
continent. The first stage is a 700m hill climb:

http://www.tourdewhiterock.ca/race_details.php

The Tour de Delta, generally contested by the same riders, more or less,
starts with a 3km (flat) prologue:

http://www.tourdedelta.com/theRace.html#

Of course, that's only if we ignore the potential aero advantage of a
downtube water-bottle.

But if you had a 0.2 mph tailwind on your run, you'd have carried your
water bottle up the hill in the same 8.00 minutes and beaten the other
rider if he climbed in still air by the same 1-second margin.

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.

The goal, then, is to make sure your performance margin is greater than
wind variance. But if you can't have that, at least do everything else
right. You might just win, and the marginal effort of getting a lot of
these choices right is . . . negligible?

Dear Ryan,

As I said, it's easy to get lost in the details.

The example was a 1-lb piece of uselessness, an order of magnitude (or
more) greater than the kind of minutiae usually being debated here.

Who carries a full water bottle in an 8-minute time trial up a hill?

Cheers,

Carl Fogel

On Mar 6, 8:31*pm, wrote:
On Sat, 07 Mar 2009 03:13:16 GMT, Ryan Cousineau
wrote:



In article ,
wrote:

On Fri, 6 Mar 2009 12:26:43 -0800 (PST), Bret
wrote:

Now that I think about it. That second picture is from a hillclimb TT
(Cat 3 Killington Prologue) where I won by 1 sec in a race that lasted
slightly under eight minutes. That's a .2% margin. If I had carried a
water bottle I probably wouldn't have won.

Bret

Dear Bret,

Heck, if you'd had a different starting time up the hill, you might
not have won.

Sometimes it's easy to get lost in the details.

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

To get an idea of what's involved, have some fun with this
side-by-side calculator:
*http://bikecalculator.com/veloUS.html

Plug 315.722 watts into both sides, use tubulars, on the hoods, 5.5%
grade, 1.7 miles, and you should get 8.00 minutes.

Raise the power by a hundredth of a watt to 315.723, and the time
drops to 7.99 minutes.

Lower the power by 0.506 watts to 315.216 watts and the time rises to
8.01 minutes.

Add 1-lb for a water bottle at 315.722 watts, and the speed drops to
8.03 minutes, 1.8 seconds less.

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.

It's not that weird. I once competed in a hill climb that took me 12
minutes. I missed the podium by less than 3/10ths of a second. I spent a
lot of time thinking about those 3/10ths.

http://wiredcola.com/content/my-first-timetrial

Here's a race that is contested by some of the top riders on this
continent. The first stage is a 700m hill climb:

http://www.tourdewhiterock.ca/race_details.php

The Tour de Delta, generally contested by the same riders, more or less,
starts with a 3km (flat) prologue:

http://www.tourdedelta.com/theRace.html#

Of course, that's only if we ignore the potential aero advantage of a
downtube water-bottle.

But if you had a 0.2 mph tailwind on your run, you'd have carried your
water bottle up the hill in the same 8.00 minutes and beaten the other
rider if he climbed in still air by the same 1-second margin.

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.

The goal, then, is to make sure your performance margin is greater than
wind variance. But if you can't have that, at least do everything else
right. You might just win, and the marginal effort of getting a lot of
these choices right is . . . negligible?

Dear Ryan,

As I said, it's easy to get lost in the details.

The example was a 1-lb piece of uselessness, an order of magnitude (or
more) greater than the kind of minutiae usually being debated here.

Who carries a full water bottle in an 8-minute time trial up a hill?

I did. If you go back and look at the '87 photo from the same race
you'll see a bottle in the cage. I don't remember why. I probably just
forgot to remove it. Another difference is that I was wearing a
skinsuit in '89. Both of those differences probably contributed to my
1 sec win in '89. The lighter eyewear may also have been a factor. I
think that I was 4th in '87.

Bret

On Fri, 6 Mar 2009 17:14:43 -0800 (PST), jwbinpdx
wrote:

I don't think Frank is saying that new equipment is no better than
retro equipment.

Maybe not in the last couple of posts about 1980s equipment, but it's
the inevitable result if you follow is line of reasoning.

On Fri, 6 Mar 2009 17:29:26 -0800 (PST), Bret
wrote:

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.

Dude!

I was in the field in that, in the 3s, I think. I got sixth or
seventh on one of the hilly road stages (maybe there was only one --
that is, it was a three-stage race maybe that year) but never found
out since it was taking soooo long to wrap up results. There was half
a bike length between me and the guy behind me and 5 or 10 lengths to
the guy in front of me. This was a stage finishing not at the very
top but on the flats next to the parking lot below that.

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.

On Fri, 6 Mar 2009 21:13:04 -0600, "Sandy" wrote:

There are rather few tires which are offered in identical models and in
these two sizes. With the larger tire may be a plus in comfort, perhaps
rolling resistance, but these will be not the ones typically compared. A
Vittoria Rubino Pro 25 can be just as commonly compared to a 23 of the same
model, but may not compare positively to a Vittoria EVO-KX of the same size
with regard to the same elements noted.

As I said, earlier in this thread, this all depends on rider weight,
the roads they ride on and the speed and circumstances in which they
ride. What is right for a 100 pound woman is not ideal for a 200
pound person. What is ideal in a time trial on good roads is probably
not as good, or even as fast for a bumpy road race.

On Fri, 06 Mar 2009 20:31:55 -0700, wrote:

The example was a 1-lb piece of uselessness, an order of magnitude (or
more) greater than the kind of minutiae usually being debated here.

"order of magnitude (or more) greater than the kind of minutiae"

We see the backtracking now. Sweet.