Steel is Real and Carbon is Lighter

On Wednesday, June 19, 2019 at 3:10:11 PM UTC-7, wrote:
On Wednesday, June 19, 2019 at 3:27:59 PM UTC-5, sms wrote:

But it isn't just weight.

There is a significant performance difference between a well-made steel
racing frame and a carbon-fiber frame.

Please give some factual, objective reasons for this mythical "significant performance difference" you cite. Other than frame/fork weight. Carbon will most likely be lighter in weight than a steel bicycle. And weight can make a difference in acceleration and climbing speed. Now I will give you the fact the fastest bicycle in the world (183.9mph) does appear to be a carbon KHS frame with a motorcycle shock fork on the front.

https://www.bicycling.com/news/a2328...-speed-record/

The steel frame handles and
corners better and of course will last much longer. The lower weight of
the carbon-fiber frame, as well as all the other carbon-fiber pieces, is
the appeal to racers of carbon.

Yes the generally lighter weight of carbon over steel is appealing to racers. But why do you think steel handles and corners better than carbon? Seems to me if all the frames are made with the same angles and lengths, handling should be equal regardless of weight. What magical property is in steel that allows it to stick to the road better than carbon? Lean more in turns. Make tighter turns. Float over the road surface?

And why do you think steel "will last much longer"? Steel can rust. Carbon doesn't. Steel bicycle tubes are very thin. Easy to dent and crumple. Carbon frame tubes probably thicker. I have a broken steel Don Walker bicycle frame hanging in my garage. He makes VERY high end custom steel frames. Yet it broke.

https://www.donwalkercycles.com/

I haven't ridden all of the CF bikes out there but I have a Time VX Elite, I sold a Colnago C40, a Look C246 and my present Colnago CLX 3.0. They are all hell and gone too stiff (except for the old style Look which was way too slack).

The Basso Loto and the Pinarello Stelvio handle almost perfectly with the Pinarello having a slight edge. The roads here are trashed and the CF bikes are likely to be so inflexible that they will throw the water bottles out of the holders. The steel bikes wouldn't even get close to that. They only flex under very high forces and they don't spring back like the carbon bikes do - they simply ease back. At the bottom of a very steep descent locally the road flattens almost instantly. The CF bikes absorb this force in the tires whereas the steel bikes absorb it in the frames and forks and so don't threaten to bottom out the tires. In any case the steel bikes seem to have better control.

Now if only I had better performance.

On Wednesday, June 19, 2019 at 4:45:18 PM UTC-7, jbeattie wrote:
On Wednesday, June 19, 2019 at 11:18:52 AM UTC-7, 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.

Well, go to all the reviews of retro bikes on GCN. E.g. https://www.youtube.com/watch?v=V4JAvQCp8ww Again, go borrow a 15lb modern racing bike that fits, then do hill repeats. Now do that on a Biketown bike. Really, there is no difference! It's all placebo effect! Now do it on a Surly Moonlander. No difference!

At what point would you agree there is a difference -- and why that point? Even without almighty "data" (presumably something created by a machine and not anecdotal reports), most of us would agree that some bikes are dogs and others aren't.

-- Jay Beattie.

There is no doubt at all that a 15 lb bike will do more hill repeats faster.. But that isn't doing a 60 mile ride like I did yesterday with only 2,600 feet of climbing.

On Thursday, June 20, 2019 at 2:00:25 PM UTC-7, Frank Krygowski wrote:
On 6/20/2019 1:26 PM, jbeattie wrote:
On Thursday, June 20, 2019 at 9:23:12 AM UTC-7, Frank Krygowski wrote:
On 6/20/2019 10:23 AM, jbeattie wrote:
On Wednesday, June 19, 2019 at 5:32:05 PM UTC-7, Frank Krygowski wrote:
On 6/19/2019 7:45 PM, jbeattie wrote:
On Wednesday, June 19, 2019 at 11:18:52 AM UTC-7, 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.

Well, go to all the reviews of retro bikes on GCN. E.g. https://www..youtube.com/watch?v=V4JAvQCp8ww Again, go borrow a 15lb modern racing bike that fits, then do hill repeats. Now do that on a Biketown bike. Really, there is no difference! It's all placebo effect! Now do it on a Surly Moonlander. No difference!

At what point would you agree there is a difference -- and why that point? Even without almighty "data" (presumably something created by a machine and not anecdotal reports), most of us would agree that some bikes are dogs and others aren't.

Geez, guys, you're very diligent about confusing yourselves!

As I told Sir, I'm _not_ saying weight doesn't make a difference! I'm
quantifying that difference.

Didn't we all meet guys in the 1970s who thought "My new bike has six
cogs instead of five, so it's going to be 20% faster"? Don't we still
meet guys who think 11 cogs will be 10% faster than ten cogs? But that's
silly and very unscientific. It shows a poor grasp of basic physics

In the same way, there seem to be people who think "My old bike weighed
20 pounds but my new bike is 18 pounds. It's going to be 10% faster up a
hill."

Sorry! What matters is total weight, bike+rider. a 160 pound guy who
goes from a 20 pound bike to an 18 pound bike has lost 2 out of 180
pounds. He's improved the total weight by about 1%.

Will it make a difference? Yes, a difference of about 1%. So weight
_does_ matter - that much.

"Oh, but try a bike that's FIVE pounds lighter!!" OK, that one will be
2.8% better. It won't be 25% better.

If 1% or 2.8% is worth it to you, fine. It is to some people. Other
people may have a different view....

Applying a formula and coming up with a "percentage better" based on total bicycle and rider weight is deceptive. A better paradigm is lifting weights -- moving 15 pounds uphill rather than 20.

Sorry, Jay. Lifting weights is probably the worst analogy for your position.

Picking a weight lifting exercise at random: How many times can you curl
20 pounds? Maybe 30 times? So if you reduce the weight to 15 pounds, you
can curl it many times more, right?

Sure. But that's because that is essentially ALL that you are lifting!
The only other weight is that of your forearm, and it's close to negligible.

When you lift (AKA pedal) your 15 pound bike up the hill, it's the
_bike's_ weight that's close to negligible. The main problem is your own
160 - 180 pounds, or whatever you weigh. It's the opposite of weight
lifting.


You have to determine the additional energy needed to move that weight and how the additional energy affects the rider over time. Energy needed may depend on frame flex, tires and a number of other factors that are bicycle dependent.

My whole point is that the energy needed to move that weight uphill is
easily quantified. And the way most non-mathematical people visualize it
is wrong.

Tires? Yes, that effect if fairly easily quantified as well. Not
perfectly, at least as it's usually done, because standard rolling
resistance data measures only the part of the relevant losses within the
tire. But at least the rolling resistance issue doesn't get the same
blatant mistake that weight does. IOW, people don't seem to think "These
tires have a CRR of 0.003, and my old ones were 0.004, so I'm going to
be 25% faster."

Frame flex? I'm not aware of any serious attempt to quantify increases
in speed due to stiffening a frame. I like a stiff frame, but I suspect
it's roughly as effective as painting the bike red.

The effect on the rider depends on many things. We are not constant speed motors. Assuming a rider is attempting to maintain the same speed on a heavier and less efficient bike, the additional effort may be enough to exhaust him or her before the top of a climb -- which turns the last miles into a creep-along. Time is not off by 2% based on some formula but is off by more -- depending on how badly he or she blows. When you run the tank out, you could end up walking the last miles or sitting under a tree and resting.

First, understand that when I say 2% weight reduction yields about 2%
speed, I'm talking about climbing speed. So your total time is not "off
by 2%." Total time is probably off by a lot less, since on the level, a
2% weight reduction causes a benefit of only 2% times your rolling
resistance coefficient. That's maybe 0.02 * 0.004 = 0.008%, roughly. And
on a downhill, less weight means you descend a tiny bit slower.

I think the real and important thing at work is psychology. Riders are
swearing they ride much better with a bike that's a couple pounds
lighter. Some are claiming they ride much better if there's an extra
cog; or if there's exactly the right cog, like a 17 instead of an 18,
for whatever percentage of the ride that actually uses that cog. Or they
ride much better if the fork is stiffer; or they have their best shorts,
or their lucky socks, or their new paint job.

But I know I've had good days and bad days, even on the same day. There
was a day last year when I was telling people "I'm going to have to head
back home. I just don't have it today, I can't keep up." I was urged to
keep going and I slaved along just to hold someone's draft, until about
seven miles from the end, when I suddenly felt great. The leader said
"You took off like a bat out of hell!"

Well, it wasn't because my bike lost five pounds, or my tires suddenly
rolled better or my handlebar bag lost its air resistance. It just
happened.

If a couple pounds less bike makes it way more fun for you, that's fine.
But at a certain point, maybe this discussion should move from
rec.bicycles.tech to rec.bicycles.psychology

If you put two pounds on your bike, you are lifting -- or moving, however you want to characterize it -- two more pounds. It may represent a small fraction of rider/bike weight, but the problem with analyzing this mathematically is that rider weight produces power and bottle weight doesn't. The effect of the additional weight is rider dependent. That's all I'm saying. Doing this as a math experiment doesn't work.

Assume on your best day and lightest bike that you are red-lining keeping up with the group on a climb. Then you add lets say 5 pounds by riding your swampy, soft gravel bike. You will go beyond red-lining to hold on, and then you will blow. You will be catching your breath, slowing down so your heart doesn't explode and pondering a call to Uber. You will not be off by some linear amount of time produced by a mathematical formula. You will be stopping for a picnic.

Sure, that 2% difference could push your over some hard and fast limit.
If, that is, you were actually at a hard and fast limit. If you didn't
get a swirl of tailwind that the lead rider missed. If you didn't get
get angry, or grit your teeth harder, or otherwise get a few drops of
adrenaline. If you didn't get a little better run at the start of the
hill. If you hadn't lost some body fat since the last ride. If you
weren't riding behind a big guy with a bigger draft. If you didn't hit a
little patch of road that was smoother than what the other guys happened
to hit. If ...

(BTW, on the day described above, I did think I was at my limit. I
actually lay down in the road while others in the group fixed a guys flat..)

I just don't think the magic is all that consistent, given the dozen
other factors that affect making it up a particular hill. I'm not saying
weight doesn't make a difference. But I think for small weight changes,
it's almost never a critical difference - except maybe psychologically.

And I notice you chose five pounds for your example, which gives a bit
over 2% more climbing speed. I also ran numbers for two pounds, yielding
1% difference in climbing speed. Would you agree that the two pounds,
one percent is negligible?

How about one pound? Half a pound? 100 grams? Where, exactly, does the
magic kick in?

I was guessing at the weight difference between the Emonda and my gravel bike. The magic may kick in at +50g if the slightly heavier bike has 25mm low RR tires and the other has 35mm knobby CX tires and a whippy frame. I was faster on a slightly heavier version of the early '90s Cannondale 2.8 when I swapped out the OE aluminum pogo-stick forks and put in early CF Kestrel forks with a steel steerer. Cannondale had gone over the edge lightening up the front end to the point that it was hard to control the bike in a sprint.

On Friday, June 21, 2019 at 9:35:34 AM UTC-7, Tom Kunich wrote:
On Wednesday, June 19, 2019 at 4:45:18 PM UTC-7, jbeattie wrote:
On Wednesday, June 19, 2019 at 11:18:52 AM UTC-7, 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.

Well, go to all the reviews of retro bikes on GCN. E.g. https://www.youtube.com/watch?v=V4JAvQCp8ww Again, go borrow a 15lb modern racing bike that fits, then do hill repeats. Now do that on a Biketown bike. Really, there is no difference! It's all placebo effect! Now do it on a Surly Moonlander. No difference!

At what point would you agree there is a difference -- and why that point? Even without almighty "data" (presumably something created by a machine and not anecdotal reports), most of us would agree that some bikes are dogs and others aren't.

-- Jay Beattie.

There is no doubt at all that a 15 lb bike will do more hill repeats faster. But that isn't doing a 60 mile ride like I did yesterday with only 2,600 feet of climbing.

Today's ride: https://localfreshies.com/wp-content...ak_2014_V1.jpg Mt. Bachelor. The winds were howling at the top, and I almost had a Froome moment coming down -- and I was on modest C35s and not super deep-dish sails.

-- Jay Beattie.

On Friday, June 21, 2019 at 6:55:05 PM UTC-4, jbeattie wrote:
Snipped
Today's ride: https://localfreshies.com/wp-content...ak_2014_V1.jpg Mt. Bachelor. The winds were howling at the top, and I almost had a Froome moment coming down -- and I was on modest C35s and not super deep-dish sails.

-- Jay Beattie.

Gusty or strong side winds can do a real number on a bicyclist if the bicyclist takes a hand off the handlebar at just the wrong moment. The deeper the rim the more hairy it can be.

Cheers

jbeattie wrote:
On Thursday, June 20, 2019 at 2:00:25 PM UTC-7, Frank Krygowski wrote:
On 6/20/2019 1:26 PM, jbeattie wrote:
On Thursday, June 20, 2019 at 9:23:12 AM UTC-7, Frank Krygowski wrote:
On 6/20/2019 10:23 AM, jbeattie wrote:
On Wednesday, June 19, 2019 at 5:32:05 PM UTC-7, Frank Krygowski wrote:
On 6/19/2019 7:45 PM, jbeattie wrote:
On Wednesday, June 19, 2019 at 11:18:52 AM UTC-7, 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.

Well, go to all the reviews of retro bikes on GCN. E.g.
https://www.youtube.com/watch?v=V4JAvQCp8ww Again, go borrow a
15lb modern racing bike that fits, then do hill repeats. Now do
that on a Biketown bike. Really, there is no difference! It's all
placebo effect! Now do it on a Surly Moonlander. No difference!

At what point would you agree there is a difference -- and why that
point? Even without almighty "data" (presumably something created
by a machine and not anecdotal reports), most of us would agree
that some bikes are dogs and others aren't.

Geez, guys, you're very diligent about confusing yourselves!

As I told Sir, I'm _not_ saying weight doesn't make a difference! I'm
quantifying that difference.

Didn't we all meet guys in the 1970s who thought "My new bike has six
cogs instead of five, so it's going to be 20% faster"? Don't we still
meet guys who think 11 cogs will be 10% faster than ten cogs? But that's
silly and very unscientific. It shows a poor grasp of basic physics

In the same way, there seem to be people who think "My old bike weighed
20 pounds but my new bike is 18 pounds. It's going to be 10% faster up a
hill."

Sorry! What matters is total weight, bike+rider. a 160 pound guy who
goes from a 20 pound bike to an 18 pound bike has lost 2 out of 180
pounds. He's improved the total weight by about 1%.

Will it make a difference? Yes, a difference of about 1%. So weight
_does_ matter - that much.

"Oh, but try a bike that's FIVE pounds lighter!!" OK, that one will be
2.8% better. It won't be 25% better.

If 1% or 2.8% is worth it to you, fine. It is to some people. Other
people may have a different view....

Applying a formula and coming up with a "percentage better" based on
total bicycle and rider weight is deceptive. A better paradigm is
lifting weights -- moving 15 pounds uphill rather than 20.

Sorry, Jay. Lifting weights is probably the worst analogy for your position.

Picking a weight lifting exercise at random: How many times can you curl
20 pounds? Maybe 30 times? So if you reduce the weight to 15 pounds, you
can curl it many times more, right?

Sure. But that's because that is essentially ALL that you are lifting!
The only other weight is that of your forearm, and it's close to negligible.

When you lift (AKA pedal) your 15 pound bike up the hill, it's the
_bike's_ weight that's close to negligible. The main problem is your own
160 - 180 pounds, or whatever you weigh. It's the opposite of weight
lifting.


You have to determine the additional energy needed to move that
weight and how the additional energy affects the rider over time.
Energy needed may depend on frame flex, tires and a number of other
factors that are bicycle dependent.

My whole point is that the energy needed to move that weight uphill is
easily quantified. And the way most non-mathematical people visualize it
is wrong.

Tires? Yes, that effect if fairly easily quantified as well. Not
perfectly, at least as it's usually done, because standard rolling
resistance data measures only the part of the relevant losses within the
tire. But at least the rolling resistance issue doesn't get the same
blatant mistake that weight does. IOW, people don't seem to think "These
tires have a CRR of 0.003, and my old ones were 0.004, so I'm going to
be 25% faster."

Frame flex? I'm not aware of any serious attempt to quantify increases
in speed due to stiffening a frame. I like a stiff frame, but I suspect
it's roughly as effective as painting the bike red.

The effect on the rider depends on many things. We are not constant
speed motors. Assuming a rider is attempting to maintain the same
speed on a heavier and less efficient bike, the additional effort may
be enough to exhaust him or her before the top of a climb -- which
turns the last miles into a creep-along. Time is not off by 2% based
on some formula but is off by more -- depending on how badly he or
she blows. When you run the tank out, you could end up walking the
last miles or sitting under a tree and resting.

First, understand that when I say 2% weight reduction yields about 2%
speed, I'm talking about climbing speed. So your total time is not "off
by 2%." Total time is probably off by a lot less, since on the level, a
2% weight reduction causes a benefit of only 2% times your rolling
resistance coefficient. That's maybe 0.02 * 0.004 = 0.008%, roughly. And
on a downhill, less weight means you descend a tiny bit slower.

I think the real and important thing at work is psychology. Riders are
swearing they ride much better with a bike that's a couple pounds
lighter. Some are claiming they ride much better if there's an extra
cog; or if there's exactly the right cog, like a 17 instead of an 18,
for whatever percentage of the ride that actually uses that cog. Or they
ride much better if the fork is stiffer; or they have their best shorts,
or their lucky socks, or their new paint job.

But I know I've had good days and bad days, even on the same day. There
was a day last year when I was telling people "I'm going to have to head
back home. I just don't have it today, I can't keep up." I was urged to
keep going and I slaved along just to hold someone's draft, until about
seven miles from the end, when I suddenly felt great. The leader said
"You took off like a bat out of hell!"

Well, it wasn't because my bike lost five pounds, or my tires suddenly
rolled better or my handlebar bag lost its air resistance. It just
happened.

If a couple pounds less bike makes it way more fun for you, that's fine.
But at a certain point, maybe this discussion should move from
rec.bicycles.tech to rec.bicycles.psychology

If you put two pounds on your bike, you are lifting -- or moving,
however you want to characterize it -- two more pounds. It may
represent a small fraction of rider/bike weight, but the problem with
analyzing this mathematically is that rider weight produces power and
bottle weight doesn't. The effect of the additional weight is rider
dependent. That's all I'm saying. Doing this as a math experiment doesn't work.

Assume on your best day and lightest bike that you are red-lining
keeping up with the group on a climb. Then you add lets say 5 pounds
by riding your swampy, soft gravel bike. You will go beyond red-lining
to hold on, and then you will blow. You will be catching your breath,
slowing down so your heart doesn't explode and pondering a call to
Uber. You will not be off by some linear amount of time produced by a
mathematical formula. You will be stopping for a picnic.

Sure, that 2% difference could push your over some hard and fast limit.
If, that is, you were actually at a hard and fast limit. If you didn't
get a swirl of tailwind that the lead rider missed. If you didn't get
get angry, or grit your teeth harder, or otherwise get a few drops of
adrenaline. If you didn't get a little better run at the start of the
hill. If you hadn't lost some body fat since the last ride. If you
weren't riding behind a big guy with a bigger draft. If you didn't hit a
little patch of road that was smoother than what the other guys happened
to hit. If ...

(BTW, on the day described above, I did think I was at my limit. I
actually lay down in the road while others in the group fixed a guys flat.)

I just don't think the magic is all that consistent, given the dozen
other factors that affect making it up a particular hill. I'm not saying
weight doesn't make a difference. But I think for small weight changes,
it's almost never a critical difference - except maybe psychologically.

And I notice you chose five pounds for your example, which gives a bit
over 2% more climbing speed. I also ran numbers for two pounds, yielding
1% difference in climbing speed. Would you agree that the two pounds,
one percent is negligible?

How about one pound? Half a pound? 100 grams? Where, exactly, does the
magic kick in?

I was guessing at the weight difference between the Emonda and my gravel
bike. The magic may kick in at +50g if the slightly heavier bike has 25mm
low RR tires and the other has 35mm knobby CX tires and a whippy frame. I
was faster on a slightly heavier version of the early '90s Cannondale 2.8
when I swapped out the OE aluminum pogo-stick forks and put in early CF
Kestrel forks with a steel steerer. Cannondale had gone over the edge
lightening up the front end to the point that it was hard to control the bike in a sprint.

-- Jay Beattie.



I think all things being equal, lighter is probably faster. But all things
are rarely equal.

--
duane

On Friday, June 21, 2019 at 3:55:05 PM UTC-7, jbeattie wrote:
On Friday, June 21, 2019 at 9:35:34 AM UTC-7, Tom Kunich wrote:
On Wednesday, June 19, 2019 at 4:45:18 PM UTC-7, jbeattie wrote:
On Wednesday, June 19, 2019 at 11:18:52 AM UTC-7, 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.

Well, go to all the reviews of retro bikes on GCN. E.g. https://www.youtube.com/watch?v=V4JAvQCp8ww Again, go borrow a 15lb modern racing bike that fits, then do hill repeats. Now do that on a Biketown bike. Really, there is no difference! It's all placebo effect! Now do it on a Surly Moonlander. No difference!

At what point would you agree there is a difference -- and why that point? Even without almighty "data" (presumably something created by a machine and not anecdotal reports), most of us would agree that some bikes are dogs and others aren't.

-- Jay Beattie.

There is no doubt at all that a 15 lb bike will do more hill repeats faster. But that isn't doing a 60 mile ride like I did yesterday with only 2,600 feet of climbing.

Today's ride: https://localfreshies.com/wp-content...ak_2014_V1.jpg Mt. Bachelor. The winds were howling at the top, and I almost had a Froome moment coming down -- and I was on modest C35s and not super deep-dish sails.

-- Jay Beattie.

This was why I wanted to make the point that these cheapo deep aero clinchers do not run off on me - they are no more sensitive to side gusts than some of those old Campy Proton wheels which were flat sections.

I assumption is that it is the spoke tension but it may be the directional stability of the Victoria Corsa G+ tires. I've used these clinchers on the Aero frame of the Colnago and the very non-aero frame of the Pinarello Stelvio and they seem to react that same way. For $300 with free shipping you can hardly do bad. Also the Novatec hubs are really nice.

https://www.ebay.com/itm/700C-50mm-D...6LRx ckDCkTIQ

You can get them for Shimano or Campy.

On 6/22/2019 3:16 PM, Tom Kunich wrote:
On Friday, June 21, 2019 at 3:55:05 PM UTC-7, jbeattie wrote:

Today's ride: https://localfreshies.com/wp-content...ak_2014_V1.jpg Mt. Bachelor. The winds were howling at the top, and I almost had a Froome moment coming down -- and I was on modest C35s and not super deep-dish sails.

-- Jay Beattie.

This was why I wanted to make the point that these cheapo deep aero clinchers do not run off on me - they are no more sensitive to side gusts than some of those old Campy Proton wheels which were flat sections.

I assumption is that it is the spoke tension but it may be the directional stability of the Victoria Corsa G+ tires. I've used these clinchers on the Aero frame of the Colnago and the very non-aero frame of the Pinarello Stelvio and they seem to react that same way.

OK, my guess on crosswind stability and aero wheels:

With an old fashioned, unstreamlined sort of box section rim, the cross
section of the forward part of wheel is a simple bluff body. Air hits it
and goes turbulent no matter what the angle of attack - that is, no
matter if there's zero wind, or if there's a sidewind causing the air to
come at the rim at an angle. So the front and rear portions of the wheel
get roughly the same amount and direction of force.

The more a tire+rim looks like a teardrop or airfoil, the less that is
true. The airfoil shape will certainly give less drag if it's pointed
directly into the relative wind (that is, if there is no sidewind). But
for many values of sidewind, the relative wind is at an angle of attack
that causes a significant sideways "lifting" force on the front part of
the wheel. [Rather, it would be a lifting force if the airfoil were
horizontal, as an airplane wing.] On the bike, this is a lateral force
that tries to steer the front of the wheel away from the wind. The
backside of the wheel sees the same angle of attack, but its airfoil is
oriented backward so it's much less efficient at generating side force.
The sideways force there is much less, so the front and rear side forces
are much less balanced than for a normal wheel.

The more streamlined the wheel+tire, the better this works. So I'm not
surprised aero wheels would be sensitive to side winds.

I don't think loose spokes have anything significant to do with this,
assuming the spokes don't go dead slack. In fact, I don't think tighter
spokes increase the rigidity of the wheel. The stiffness (or modulus of
elasticity) of a spoke with 50 kgf tension is the same as a spoke with
100 kgf tension. They're both within the elastic range of the material,
where strain is proportional to stress, so the same force will cause the
same deflection.

That's what I think. We can discuss.

--
- Frank Krygowski

On Fri, 21 Jun 2019 09:15:50 -0700 (PDT), Tom Kunich
wrote:

On Wednesday, June 19, 2019 at 9:49:48 AM UTC-7, duane wrote:
On 19/06/2019 10:25 a.m., 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.

-- Jay Beattie.


5lbs? My Tarmac is probably closer to 12 lbs lighter than my cro moly
Volpe.

And no in reality it's not a subtle or imagined difference. And no,
it's not just about weight unless everything else is exactly the same.

I changed my Look pedals from CX 6 cyclocross pedals which are very easy to get into and put 206's on which were much lighter. Then since I had those 50 mm deep clinchers just sitting there I installed those The "out-the-door" weight was 21.7 lbs. for the Pinarello. I'm pulling my Basso apart to refinish it and I have another set of cheap Chinese tubeless wheels that I'll install when it get's back together. Also I think that my 44 mm bars are too wide so will reduce this to 42 mm. Chinese carbon bars as well. I think that I can keep a steel bike and have it about the same weight as the Colnago. Granted that the Colnago is not an ultra-light but my friend is touring Italy and he went to a bike factory and they advised him against buying carbon. They said that they support a racing team with these ultra-lights but that they are replaced every single race. They say that there's no way that you can get any reliability out of a piece of cloth that tears with resin on it that cracks.

That last is a rather strange statement given that practically all
modern recreation and work boats are made from a mixture of cloth and
resin. Do you mean that my 15 year old, 40 ft sloop, that had sailed
across the pacific ocean and that I sailed from Thailand to Australia
and back was prone to crack?

Or is this just another of your poorly thought out and wild eyed
statements.


Well, that sold me. Wheels and handlebars can be carbon because the loads put on those are fatigue and CF has almost infinite fatigue resistance.
--
cheers,

John B.

On Saturday, June 22, 2019 at 6:17:42 PM UTC-4, John B. wrote:
On Fri, 21 Jun 2019 09:15:50 -0700 (PDT), Tom Kunich
wrote:
Snipped
Granted that the Colnago is not an ultra-light but my friend is touring Italy and he went to a bike factory and they advised him against buying carbon. They said that they support a racing team with these ultra-lights but that they are replaced every single race. They say that there's no way that you can get any reliability out of a piece of cloth that tears with resin on it that cracks.

That last is a rather strange statement given that practically all
modern recreation and work boats are made from a mixture of cloth and
resin. Do you mean that my 15 year old, 40 ft sloop, that had sailed
across the pacific ocean and that I sailed from Thailand to Australia
and back was prone to crack?

Or is this just another of your poorly thought out and wild eyed
statements.

Snipped

John B.

You got it John B.

Canoes and kayaks and a lot of power boats are often made of a polyester cloth and/or polyester mat impregnated with polyester resin. Some of those boats are even made with a Kevlar fabric and epoxy resin.

Cheers