Creeping brake pad drag

Frank Krygowski writes:

On Sunday, November 24, 2019 at 2:00:26 PM UTC-5, Radey Shouman wrote:
Frank Krygowski writes:



My point was not that I would actually make one. My point was that
manual (non-STI) shifting is a truly simple system. Despite your
claims, Di2 is not a simple system. The complexity is hidden inside an
unrepairable box that you replace if it goes bad, but the complexity
is there.

For either system, equally, most of the complexity is hidden in the
design of the chain, and gears. The chain is unrepairable, and all of
us replace it when it goes bad. When the zombie apocalypse comes, we'll
ride bicycles just as long as the chain supply holds out, and no longer.

Focus, please! The difference in complexity between the two systems is not the
chain, the cogs or the mechanical parts of the derailleur - i.e. the parallelogram
linkage and the jockey wheel setup. Those are essentially identical, whether
moved by cable or Di2.

Once you start riding a chain-driven, rubber tired, multi-gear bicycle,
you have eaten the apple of complex, throw-away industrial products.
Things that no single person knows how to make -- recall Doug
Cimperman's postings here on making tires, and as I recall he was buying
all the materials he practically could. Now this argument sometimes
meets resistance from those unfamiliar with the engineering mode of
thought, but my point is that the additional complexity, if there is
any, of replacing springs and bespoke clockwork with batteries and
microprocessors, is /negligible/, it is /in the noise/.

No sense worrying about it at all.

There are reasons to prefer older stuff, it's proven, and you know how
to deal with it. I understand that attitude as an extremely late
adopter myself. I buy my coffee with folding money, I heat my house
with steam, I shift my bicycle using friction shifters on the downtube,
I long for the world of payphones, and know of two lonely holdouts
in my vicinity.

I am not likely ever to have an electronically shifted bike with with
hydraulic brakes, even when they're a dime a dozen on craigslist. But
that's just /my/ personal preference, not some eternal verity nor
engineering principle.

The difference in complexity is the lever, cable and a bit of cable housing vs.
some pushbuttons, an electronic actuator of some kind (probably a stepper motor)
a collection of microelectronic bits and a few hundred lines of code.

And as a final detail, I wasn't comparing Di2 against STI. Think barcons. If you
like, make them index barcons, because the detents don't add much complexity.

Finally, I'll repeat that I'm not saying Di2 doesn't work, or can't be reliable,
or should be abolished. I'm saying that in my view, its benefits are not worth
its detriments.

What you're really saying is that it offends your esthetic sense.
That's fine, /you/ don't have to use it. Bowden cables (ever tried to
make one of those?) will be available for the foreseeable future.

On Monday, November 25, 2019 at 8:02:32 AM UTC-8, Radey Shouman wrote:
Frank Krygowski writes:

On Sunday, November 24, 2019 at 2:00:26 PM UTC-5, Radey Shouman wrote:
Frank Krygowski writes:



My point was not that I would actually make one. My point was that
manual (non-STI) shifting is a truly simple system. Despite your
claims, Di2 is not a simple system. The complexity is hidden inside an
unrepairable box that you replace if it goes bad, but the complexity
is there.

For either system, equally, most of the complexity is hidden in the
design of the chain, and gears. The chain is unrepairable, and all of
us replace it when it goes bad. When the zombie apocalypse comes, we'll
ride bicycles just as long as the chain supply holds out, and no longer.

On Monday, November 25, 2019 at 4:43:52 PM UTC+1, Sir Ridesalot wrote:
On Monday, 25 November 2019 09:27:59 UTC-5, wrote:
On Monday, November 25, 2019 at 4:57:17 AM UTC+1, Frank Krygowski wrote:
On 11/24/2019 8:08 PM, Sir Ridesalot wrote:


So, just how much difference do those wattage differences from the video and which numbers I posted make in real life?


I just ran some numbers. Lou can check me, but here's what I got.

I fitted an equation to the "modern kit, modern bike" curve - the one
that said 25kph takes only 79 Watts (not counting rolling resistance and
drivetrain friction). The equation I got was
Power = 0.0097 * speed ^ 2.7918

The "retro" bike took 87 Watts to go 25kph. So I backsolved to find out
what speed the "modern" bike would go with 87 Watts.

I came up with 26.05 kph.

In other words, if you ditched your "retro" bike with round tubes,
square section rims, old style handlebars, etc. and spent the money on a
super-sleek aero modern bike, a 25kph rider would be able to go 26 kph.

In miles per hour, that bike would take a 15.5 mph rider all the way up
to 16.1 mph. Roughly half a mile per hour faster.

I note that you get almost as much benefit switching from wrinkled wool
clothing to an aero racing suit.

So anyone NOT riding in a super-sleek racing suit should first buy one
of those and carefully measure how much difference it makes on your
normal rides. You can probably get a set of race clothes for a hundred
bucks. See for yourself what that much difference feels like before you
spend $2000+ on a full aero bike.


--
- Frank Krygowski

1. no flappy clothes,
2. position on your bike,
3. better tires,
4. aero wheels,
5. aero bike

Lou

One of the tests in that video was a retro bike with modern kit/clothing and another test was with a modern bike with modern kit/clothing. Thus whatever difference there was should have been due to the differences with the bicycles alone not the rider. I do wonder now though if they used the same tires on all of the bikes?

Cheers

Tires didn't matter in the test. They didn't measure the rolling resistance or drive train loss. The measured the drag of the bicyle and rider wearing different clothes.

Lou

On Monday, 25 November 2019 11:45:19 UTC-5, jbeattie wrote:
On Monday, November 25, 2019 at 8:02:32 AM UTC-8, Radey Shouman wrote:
Frank Krygowski writes:

On Sunday, November 24, 2019 at 2:00:26 PM UTC-5, Radey Shouman wrote:
Frank Krygowski writes:



My point was not that I would actually make one. My point was that
manual (non-STI) shifting is a truly simple system. Despite your
claims, Di2 is not a simple system. The complexity is hidden inside an
unrepairable box that you replace if it goes bad, but the complexity
is there.

For either system, equally, most of the complexity is hidden in the
design of the chain, and gears. The chain is unrepairable, and all of
us replace it when it goes bad. When the zombie apocalypse comes, we'll
ride bicycles just as long as the chain supply holds out, and no longer.

Focus, please! The difference in complexity between the two systems is not the
chain, the cogs or the mechanical parts of the derailleur - i.e. the parallelogram
linkage and the jockey wheel setup. Those are essentially identical, whether
moved by cable or Di2.

Once you start riding a chain-driven, rubber tired, multi-gear bicycle,
you have eaten the apple of complex, throw-away industrial products.
Things that no single person knows how to make -- recall Doug
Cimperman's postings here on making tires, and as I recall he was buying
all the materials he practically could. Now this argument sometimes
meets resistance from those unfamiliar with the engineering mode of
thought, but my point is that the additional complexity, if there is
any, of replacing springs and bespoke clockwork with batteries and
microprocessors, is /negligible/, it is /in the noise/.

No sense worrying about it at all.

There are reasons to prefer older stuff, it's proven, and you know how
to deal with it. I understand that attitude as an extremely late
adopter myself. I buy my coffee with folding money, I heat my house
with steam, I shift my bicycle using friction shifters on the downtube,
I long for the world of payphones, and know of two lonely holdouts
in my vicinity.

Steam heat is incredibly complex compared to a simple forced-air, which is just a fan and a burner. My hydronic system looks like something out of the engine room in Das Boot -- and the piping for the steam system of my childhood was covered in asbestos and topped with JM blue mud, so I least I know which bankrupt company to sue when I get meso. And with no ductwork, you're screwed if you want AC unless you do some retrofit Unico or split system.

I don't miss payphones except for finding stray coins in coin returns. As a kid, they were a gold mine -- along with that penny gum machine at the Woolworths that would keep producing balls if you twisted the handle just far enough but not too far. I also like TV remotes and not having to flip LPs, which I still do, but it is an inconvenience. Paper money doubles transaction time at most registers. I would like to get rid of tip screens, however. Why should I tip you for handing me a coffee across the counter? It's gotten ridiculous. All social media could be unplugged, IMO. If I weren't typing this post, I'd probably be doing something productive.

What I don't like are the transitions between the new and the old -- first generation low volume flush toilets, fluorescent bulbs, early silica compound tires -- my leaking first generation Goretex tent. Early adopting doesn't pay.

-- Jay Beattie.

I remember reading many many years ago to let the racers adopt and perfect any new bicycle stuff. I could see where that could pay off in preventing a non-racing bicyclist from ending up with orphan stuff after it was produced for just a couple of years; Shimano AX stuff comes to mind as does the Suntour Sealed Rear Mountech derailleur I bought that exploded the next day when I pedaled from a stop when the derailleur was not precisely lined up with a rear cog. IIRC that derailleur was $75.00. What was maddening about it was that the failure wasn't warrantied and thus I was out the $75.00 and the derailleur. I'll let others adopt and experiment with new stuff.

Cheers

On 11/25/2019 9:27 AM, wrote:
On Monday, November 25, 2019 at 4:57:17 AM UTC+1, Frank Krygowski wrote:
On 11/24/2019 8:08 PM, Sir Ridesalot wrote:


So, just how much difference do those wattage differences from the video and which numbers I posted make in real life?


I just ran some numbers. Lou can check me, but here's what I got.

I fitted an equation to the "modern kit, modern bike" curve - the one
that said 25kph takes only 79 Watts (not counting rolling resistance and
drivetrain friction). The equation I got was
Power = 0.0097 * speed ^ 2.7918

The "retro" bike took 87 Watts to go 25kph. So I backsolved to find out
what speed the "modern" bike would go with 87 Watts.

I came up with 26.05 kph.

In other words, if you ditched your "retro" bike with round tubes,
square section rims, old style handlebars, etc. and spent the money on a
super-sleek aero modern bike, a 25kph rider would be able to go 26 kph.

In miles per hour, that bike would take a 15.5 mph rider all the way up
to 16.1 mph. Roughly half a mile per hour faster.

I note that you get almost as much benefit switching from wrinkled wool
clothing to an aero racing suit.

So anyone NOT riding in a super-sleek racing suit should first buy one
of those and carefully measure how much difference it makes on your
normal rides. You can probably get a set of race clothes for a hundred
bucks. See for yourself what that much difference feels like before you
spend $2000+ on a full aero bike.


--
- Frank Krygowski

1. no flappy clothes,
2. position on your bike,
3. better tires,
4. aero wheels,
5. aero bike

As an addition to "position on the bike" I'd submit "add an aero bar." I
played with my bike's aerodynamics for years. The aero bar makes the
most obvious difference.


--
- Frank Krygowski

On 11/25/2019 2:19 AM, wrote:
On Monday, November 25, 2019 at 12:32:59 AM UTC+1, Sir Ridesalot wrote:
On Sunday, 24 November 2019 18:03:26 UTC-5, wrote:
On Sunday, November 24, 2019 at 11:59:10 PM UTC+1, Frank Krygowski wrote:
On Sunday, November 24, 2019 at 3:33:45 PM UTC-5, Sir Ridesalot wrote:
On Sunday, 24 November 2019 15:14:40 UTC-5, Duane wrote:


You’re arguing with people that had the same sort of argument about
brifters.

Some people still argue that Brifters or Ergos aren't needed on ANY bicycle.

"Needed"?

I'd say brifters are needed to be competitive in a criterium race. They're
often, but not always, needed to be competitive in the final sprint of a road
race.

When else are they "needed"?

I wonder how heated the arguments would have been had the internet been around when the transition from wooden frames or from wooden wheels to metal ones or from solid rubber tires to pneumatic tires?

When pneumatic tires were introduced, it became impossible to win a race on
solid tires. The difference in rolling resistance was that dramatic. So was
the difference in comfort.

The same can be said about multiple gears. Very soon, everybody saw the advantages
and knew the benefits outweighed the detriments.

But since then, returns on technology have diminished. The benefits of most
innovations since, oh, 2000 or so are barely measurable in most situations.

- Frank Krygowski

I came across this video:

https://www.youtube.com/watch?v=1mJ06mro5fw

Lou

So the differences between a retro bike with modern kit and a modern bike with modern kit are @25hph 8 watts, @35 kph 21 Watts, and @45 kph 25 Watts. I'm not up on the Watts measurements so must ask, just how significant are those increases?

Cheers

I ride with a power meter for two years now so I think I got a feeling about numbers. For me from my experience:
recovery ride 100-110 Watts, average speed about 25-26 km/hr,
relative easy ride 140-150, Watts average speed about 28-29 km/hr
average ride 180-190 Watts, average speed about 30-31 km/hr
pushing really hard 200-210, average speed about 32-33 km/hr.
All flat terrain and moderate temperature and wind concitions.

So 15 -20 Watt increase in average power is very significant in intensity.

I know Lou is just estimating and remembering, so it's rough data. In
particular, if you plot those, you'll see the 5th data point appears to
be off the curve a bit.

But the slope of the plot also shows that even at moderate speeds (25
kph) it takes quite a power difference to gain just a little speed. Or,
in the context of the "aero" discussion, it takes quite a large change
in aerodynamics to make you noticeably faster.

(Yes, in a close race, a tiny change can be the difference between
winning and losing. But nobody responded to my query by saying "I still
race!" Is it only James that still does that?)


--
- Frank Krygowski

On 11/25/2019 8:22 AM, AMuzi wrote:
On 11/24/2019 10:15 PM, Frank Krygowski wrote:
On 11/24/2019 7:04 PM, Duane wrote:

I have 11 speed SRAM and it works well.* But honestly a
typical 105 setup
today is light years ahead of the stuff we rode in the old
days with
friction shifters and toe clips.** Anyone can argue that
new tech isn’t
necessary. Seems silly.

It probably depends on your personal definition of "necessary."

For some people, biking "necessary" is the same as a teenage
girl's definition when her mom takes her to the mall: "Mom,
_everyone_ has that style! I've _got_ to have it! It's
_necessary_!!"

For me, "necessary" means something more like "I'd be unable
to ride a bike without it. Or at least, riding without it
would be a terrible experience."


The line is very personal and dependent on taste more than engineering
analysis. I'm riding around on a bog simple fixie yet you 'need' those
complex gear choices. For another guy 2x12 suits his needs better than
his old 3x10 for reasons you may not appreciate but they are real for him.

And it depends on conditions. For my local village riding, I mostly use
a Sturmey-Archer 3 speed. For most of my riding, I use bikes that have
five (count 'em, five!) cogs in back. And I wouldn't want to do a loaded
tour without a granny chainring.

But I'd submit that the preferences for 2x12 vs. 3x10 may well be
influenced by fashion and advertising. Which is actually not a total
condemnation. I'm sure I've previously mentioned brain scans proving
that people really did prefer the wine they _thought_ was much more
expensive, even when it was the exact same wine. The advertising was
false, but the pleasure was real.

But this is (purportedly) a technical discussion group. Seems that
discussions here should give some credit to engineering analysis.


--
- Frank Krygowski

On 11/25/2019 11:45 AM, jbeattie wrote:

I don't miss payphones except for finding stray coins in coin returns. As a kid, they were a gold mine -- along with that penny gum machine at the Woolworths that would keep producing balls if you twisted the handle just far enough but not too far. I also like TV remotes and not having to flip LPs, which I still do, but it is an inconvenience. Paper money doubles transaction time at most registers.

I disagree about the paper money - at least, if the customer is (even)
older than I am. I've been stuck behind ladies baffled by the choice of
"Debit" vs. "Credit" plus "What's a PIN number? Oh, I've got that in
here somewhere..." Which is not to mention people backing up the line by
trying to call up the store's app on their new phone to find the online
coupon for ten cents off on Q-tips.

There have been times I wished they'd brought in a dozen of their
chickens' eggs to trade for their Geritol.


--
- Frank Krygowski

On Monday, 25 November 2019 12:31:40 UTC-5, Frank Krygowski wrote:
On 11/25/2019 8:22 AM, AMuzi wrote:
On 11/24/2019 10:15 PM, Frank Krygowski wrote:
On 11/24/2019 7:04 PM, Duane wrote:

I have 11 speed SRAM and it works well.Â* But honestly a
typical 105 setup
today is light years ahead of the stuff we rode in the old
days with
friction shifters and toe clips.Â*Â* Anyone can argue that
new tech isn’t
necessary. Seems silly.

It probably depends on your personal definition of "necessary."

For some people, biking "necessary" is the same as a teenage
girl's definition when her mom takes her to the mall: "Mom,
_everyone_ has that style! I've _got_ to have it! It's
_necessary_!!"

For me, "necessary" means something more like "I'd be unable
to ride a bike without it. Or at least, riding without it
would be a terrible experience."


The line is very personal and dependent on taste more than engineering
analysis. I'm riding around on a bog simple fixie yet you 'need' those
complex gear choices. For another guy 2x12 suits his needs better than
his old 3x10 for reasons you may not appreciate but they are real for him.

And it depends on conditions. For my local village riding, I mostly use
a Sturmey-Archer 3 speed. For most of my riding, I use bikes that have
five (count 'em, five!) cogs in back. And I wouldn't want to do a loaded
tour without a granny chainring.

But I'd submit that the preferences for 2x12 vs. 3x10 may well be
influenced by fashion and advertising. Which is actually not a total
condemnation. I'm sure I've previously mentioned brain scans proving
that people really did prefer the wine they _thought_ was much more
expensive, even when it was the exact same wine. The advertising was
false, but the pleasure was real.

But this is (purportedly) a technical discussion group. Seems that
discussions here should give some credit to engineering analysis.


--
- Frank Krygowski

With the number of Trolls posting here and the endless non-bicyling content I was beginning to wonder if this newsgroup was going to ever have anything bicycling related again never mind technical.

At least the guys in that video appeared to be impartial with their setup and tests.

Cheers

On 11/25/2019 10:43 AM, Sir Ridesalot wrote:
On Monday, 25 November 2019 09:27:59 UTC-5, wrote:
On Monday, November 25, 2019 at 4:57:17 AM UTC+1, Frank Krygowski wrote:
On 11/24/2019 8:08 PM, Sir Ridesalot wrote:


So, just how much difference do those wattage differences from the video and which numbers I posted make in real life?


I just ran some numbers. Lou can check me, but here's what I got.

I fitted an equation to the "modern kit, modern bike" curve - the one
that said 25kph takes only 79 Watts (not counting rolling resistance and
drivetrain friction). The equation I got was
Power = 0.0097 * speed ^ 2.7918

The "retro" bike took 87 Watts to go 25kph. So I backsolved to find out
what speed the "modern" bike would go with 87 Watts.

I came up with 26.05 kph.

In other words, if you ditched your "retro" bike with round tubes,
square section rims, old style handlebars, etc. and spent the money on a
super-sleek aero modern bike, a 25kph rider would be able to go 26 kph.

In miles per hour, that bike would take a 15.5 mph rider all the way up
to 16.1 mph. Roughly half a mile per hour faster.

I note that you get almost as much benefit switching from wrinkled wool
clothing to an aero racing suit.

So anyone NOT riding in a super-sleek racing suit should first buy one
of those and carefully measure how much difference it makes on your
normal rides. You can probably get a set of race clothes for a hundred
bucks. See for yourself what that much difference feels like before you
spend $2000+ on a full aero bike.


--
- Frank Krygowski

1. no flappy clothes,
2. position on your bike,
3. better tires,
4. aero wheels,
5. aero bike

Lou

One of the tests in that video was a retro bike with modern kit/clothing and another test was with a modern bike with modern kit/clothing. Thus whatever difference there was should have been due to the differences with the bicycles alone not the rider. I do wonder now though if they used the same tires on all of the bikes?

Cheers


While your question about performance advantage is interesting, for
those of us that aren't pure racers the real benefit (IMO) of a modern
road bike to a "retro" bike would be more about ease of use and
dependability. I'm thinking brifters over down tube friction shifters,
clipless pedals over toe straps, wider range gearing, less weight to
carry up hills etc. etc. etc.