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Why do some forks and frames have brake rotor size limits?



 
 
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  #371  
Old November 15th 17, 04:49 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,549
Default Why do some forks and frames have brake rotor size limits?

On Tue, 14 Nov 2017 19:43:00 -0600, AMuzi wrote:

On 11/14/2017 5:59 PM, John B. wrote:
On Tue, 14 Nov 2017 12:37:35 -0800, Joerg
wrote:

On 2017-11-13 19:02, Frank Krygowski wrote:
On 11/13/2017 7:03 PM, Joerg wrote:
On 2017-11-13 15:50, John B. wrote:
Seriously? California cyclists can't fix a flat tire?

Most can but they won't. I'd hoped it had become clear by now that
this is a commonly used excuse, not an admittance of incompetence.

There are many people who can't fix a flat bike tire. It's sad but true,
and it's not going to get any better.

The denizens of this group tend to be people who love bikes and are at
least reasonably competent with tools. But as I've described in the
past, I've done simple bike repairs for otherwise very intelligent
people (including engineering PhDs) who were baffled by the simplest
mechanical things.


A lot of folks are scared to break something expensive. Many simply
aren't used to do anything manual on any vehicle or other technical
equipment. Their only tools for fixing stuff are the yellow pages, the
Internet and their smart phone.


They just don't want to ride.

This is true. Again, we're an unusual group. If you gave every American
a perfectly safe, absolutely level, completely separated bike path
directly from their house to their favorite grocery store one mile away,
I doubt more than 3% would ride bikes to shop.


They would if you gave them an E-bike with a throttle-only mode. And if
it had an A/C button.

I know you don't believe it but I know it for a fact that there is a
number of people who will ride when there is a bike path. It may be only
1-3% but for America that is a lot and as you wrote yourself that alone
presents a tremendous cost savings for our health care network.


Democracy in action? Spending the tax payer's money to build something
for 1% of the population?
--
Cheers,

John B.


Yep, the new expensive kiddy path is down there past the
free public rifle range and across the way from the free
public quarter mile drag strip.


Well, I'm sure that a free rifle range is somehow guaranteed by the
2nd amendment, or perhaps the lack of one might fall under the cruel
and unusual punishment section, and of course drag strips are an
important part of the American scene. I believe the theory being if
you give them a sand box they won't play on the streets.

--
Cheers,

John B.

Ads
  #372  
Old November 15th 17, 05:08 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 2,763
Default Why do some forks and frames have brake rotor size limits?

On Tuesday, November 14, 2017 at 4:41:22 PM UTC-8, Joerg wrote:
On 2017-11-14 16:15, jbeattie wrote:
On Tuesday, November 14, 2017 at 12:37:35 PM UTC-8, Joerg wrote:
On 2017-11-13 19:02, Frank Krygowski wrote:
On 11/13/2017 7:03 PM, Joerg wrote:


[...]

They just don't want to ride.

This is true. Again, we're an unusual group. If you gave every
American a perfectly safe, absolutely level, completely separated
bike path directly from their house to their favorite grocery
store one mile away, I doubt more than 3% would ride bikes to
shop.


They would if you gave them an E-bike with a throttle-only mode.
And if it had an A/C button.


I'm dealing with an infestation of eBikes. Some woman dropped me like
a rock last night on the latest Trek super-commuter eBike while
wearing the most expensive, fully reflective Showers Pass rain
jacket.



Spandex would have been nicer if she was pretty :-)

But yeah, same here on Sunday heading up a rail trail with a buddy. We
aren't slowpokes but then we heard a whirring from behind ... zzzooom
... a guy in his 70's shot past us on an E-bike. He didn't wear fancy
clothes though.


https://www.showerspass.com/collecti...nt=27454486405
In combination with her super-bright lights, she was a human flare --
and an expensive one. She could have gotten the same dollar-to-lumen
ratio by burning $20 bills. I want all that stuff! It was he
https://tinyurl.com/y7fgaymx The "flat" route home. I was on the
better paved section to the right going up.


You guys need someone to fix those roads. A few more winters and the
underlayment is toast, meaning it can't be patched anymore.


I can't hang with the eBikes through the hills -- not without giving
myself a heart attack, and although death is part of my long-term
financial plan, I'm saving it for later.


Some guys are pushing it too far. I passed a rider last week on a hill,
probably about 65, somewhat obese but lots of leg muscles. That didn't
sit well with him so he passed me and really stepped on it, telling me
"It's on, mate!". I decided not to give chase because he was really fast
and I carried some load. Up the hill where it leveled off I closed up
quickly and he looked totally exhausted. That can't be good.


"It's on mate"(?) What a dope. I would have gone out and bought an old Silca frame pump just so I could stick it in his front wheel. "Hey, wait here; I'll be right back." I pass people all the time and couldn't imagine saying "It's on mate." I'd sign up for Death with Dignity if I did that sort of thing.

Totally OT, but I was riding up on Skyline a few months back and ran into a group of guys I raced with 30 years ago -- including a guy who was a junior prodigy back in the '70s and was in USCF development camps with Andy Hampsten and Greg LeMond. He's now CEO of a national company. We just rode along, nobody trying to prove anything, talking about the good old days. My regular cohort is like that too, except we do race each other at very predictable points in the ride. I'm slowing, so my place is no longer assured. I've learned to be more strategic, and my friends have learned to wait.

-- Jay Beattie.


  #373  
Old November 15th 17, 06:56 AM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 3,582
Default Why do some forks and frames have brake rotor size limits?

On Tuesday, November 14, 2017 at 11:08:33 PM UTC-5, jbeattie wrote:
On Tuesday, November 14, 2017 at 4:41:22 PM UTC-8, Joerg wrote:
On 2017-11-14 16:15, jbeattie wrote:

Snipped
Some guys are pushing it too far. I passed a rider last week on a hill,
probably about 65, somewhat obese but lots of leg muscles. That didn't
sit well with him so he passed me and really stepped on it, telling me
"It's on, mate!". I decided not to give chase because he was really fast
and I carried some load. Up the hill where it leveled off I closed up
quickly and he looked totally exhausted. That can't be good.


"It's on mate"(?) What a dope. I would have gone out and bought an old Silca frame pump just so I could stick it in his front wheel. "Hey, wait here; I'll be right back." I pass people all the time and couldn't imagine saying "It's on mate." I'd sign up for Death with Dignity if I did that sort of thing.

Totally OT, but I was riding up on Skyline a few months back and ran into a group of guys I raced with 30 years ago -- including a guy who was a junior prodigy back in the '70s and was in USCF development camps with Andy Hampsten and Greg LeMond. He's now CEO of a national company. We just rode along, nobody trying to prove anything, talking about the good old days. My regular cohort is like that too, except we do race each other at very predictable points in the ride. I'm slowing, so my place is no longer assured. I've learned to be more strategic, and my friends have learned to wait.

-- Jay Beattie.


Then agsin nothing's normal in Joerg's world. Is that because it's an alcohol induced alternative-reality world? Many of his posts seem to support that.
  #374  
Old November 15th 17, 08:20 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 5,392
Default Why do some forks and frames have brake rotor size limits?

On 11/14/2017 11:08 PM, jbeattie wrote:
On Tuesday, November 14, 2017 at 4:41:22 PM UTC-8, Joerg wrote:
On 2017-11-14 16:15, jbeattie wrote:
On Tuesday, November 14, 2017 at 12:37:35 PM UTC-8, Joerg wrote:
On 2017-11-13 19:02, Frank Krygowski wrote:
On 11/13/2017 7:03 PM, Joerg wrote:


[...]

They just don't want to ride.

This is true. Again, we're an unusual group. If you gave every
American a perfectly safe, absolutely level, completely separated
bike path directly from their house to their favorite grocery
store one mile away, I doubt more than 3% would ride bikes to
shop.


They would if you gave them an E-bike with a throttle-only mode.
And if it had an A/C button.

I'm dealing with an infestation of eBikes. Some woman dropped me like
a rock last night on the latest Trek super-commuter eBike while
wearing the most expensive, fully reflective Showers Pass rain
jacket.



Spandex would have been nicer if she was pretty :-)

But yeah, same here on Sunday heading up a rail trail with a buddy. We
aren't slowpokes but then we heard a whirring from behind ... zzzooom
... a guy in his 70's shot past us on an E-bike. He didn't wear fancy
clothes though.


https://www.showerspass.com/collecti...nt=27454486405
In combination with her super-bright lights, she was a human flare --
and an expensive one. She could have gotten the same dollar-to-lumen
ratio by burning $20 bills. I want all that stuff! It was he
https://tinyurl.com/y7fgaymx The "flat" route home. I was on the
better paved section to the right going up.


You guys need someone to fix those roads. A few more winters and the
underlayment is toast, meaning it can't be patched anymore.


I can't hang with the eBikes through the hills -- not without giving
myself a heart attack, and although death is part of my long-term
financial plan, I'm saving it for later.


Some guys are pushing it too far. I passed a rider last week on a hill,
probably about 65, somewhat obese but lots of leg muscles. That didn't
sit well with him so he passed me and really stepped on it, telling me
"It's on, mate!". I decided not to give chase because he was really fast
and I carried some load. Up the hill where it leveled off I closed up
quickly and he looked totally exhausted. That can't be good.


"It's on mate"(?) What a dope. I would have gone out and bought an old Silca frame pump just so I could stick it in his front wheel. "Hey, wait here; I'll be right back." I pass people all the time and couldn't imagine saying "It's on mate." I'd sign up for Death with Dignity if I did that sort of thing.

Totally OT, but I was riding up on Skyline a few months back and ran into a group of guys I raced with 30 years ago -- including a guy who was a junior prodigy back in the '70s and was in USCF development camps with Andy Hampsten and Greg LeMond. He's now CEO of a national company. We just rode along, nobody trying to prove anything, talking about the good old days. My regular cohort is like that too, except we do race each other at very predictable points in the ride. I'm slowing, so my place is no longer assured. I've learned to be more strategic, and my friends have learned to wait.


FWIW, a local mountain biker was found dead on some very tame single
track a few days ago. I didn't know him, but have friends who did. They
described him as middle aged (much younger than me), in tremendous
physical shape, built like a muscular swimmer, very low body fat, a
regular user of the YMCA etc.

Given the location, he probably wasn't pushing anywhere close to cardio
extremes. Indications are he was JRA and died instantly.

Apparently there is a correlation between long history as an endurance
athlete and atrial fibrillation and other electrical problems. Grant
Peterson has written about what he calls good exercise and bad exercise.
My views have certainly changed.


--
- Frank Krygowski
  #375  
Old November 15th 17, 11:50 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,609
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-14 17:33, John B. wrote:
On Tue, 14 Nov 2017 16:18:53 -0800, Joerg
wrote:

On 2017-11-14 15:59, John B. wrote:
On Tue, 14 Nov 2017 12:37:35 -0800, Joerg
wrote:

On 2017-11-13 19:02, Frank Krygowski wrote:


[...]

This is true. Again, we're an unusual group. If you gave every American
a perfectly safe, absolutely level, completely separated bike path
directly from their house to their favorite grocery store one mile away,
I doubt more than 3% would ride bikes to shop.


They would if you gave them an E-bike with a throttle-only mode. And if
it had an A/C button.

I know you don't believe it but I know it for a fact that there is a
number of people who will ride when there is a bike path. It may be only
1-3% but for America that is a lot and as you wrote yourself that alone
presents a tremendous cost savings for our health care network.

Democracy in action? Spending the tax payer's money to build something
for 1% of the population?



Yes. It doesn't cost 1%. As a taxpayer I want my taxes to also pay for
bike paths and not as usual roads only.


You live in California and the State has a "fuel tax" that is used for
road building and upkeep. When did you start paying fuel tax for your
bicycle?



Some educational material for you:

https://frontiergroup.org/reports/fg/who-pays-roads



Singletrack can cost next to nothing when maintained by IMBA, FATRAC or
similar volunteer organizations. Americans are quite the role model when
it comes to volunteering and donating.



And this is my favorite bike facility. Little or no tax money involved
but efficient.

--
Regards, Joerg

http://www.analogconsultants.com/
  #376  
Old November 16th 17, 12:05 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,609
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-15 11:20, Frank Krygowski wrote:
On 11/14/2017 11:08 PM, jbeattie wrote:
On Tuesday, November 14, 2017 at 4:41:22 PM UTC-8, Joerg wrote:
On 2017-11-14 16:15, jbeattie wrote:


[...]


I can't hang with the eBikes through the hills -- not without giving
myself a heart attack, and although death is part of my long-term
financial plan, I'm saving it for later.


Some guys are pushing it too far. I passed a rider last week on a hill,
probably about 65, somewhat obese but lots of leg muscles. That didn't
sit well with him so he passed me and really stepped on it, telling me
"It's on, mate!". I decided not to give chase because he was really fast
and I carried some load. Up the hill where it leveled off I closed up
quickly and he looked totally exhausted. That can't be good.


"It's on mate"(?) What a dope. I would have gone out and bought an
old Silca frame pump just so I could stick it in his front wheel.
"Hey, wait here; I'll be right back." I pass people all the time and
couldn't imagine saying "It's on mate." I'd sign up for Death with
Dignity if I did that sort of thing.


I don't see what's so bad about that. It was a good-natured enticement
to a little race except I didn't want to race up the hill. I don't like
hills.


Totally OT, but I was riding up on Skyline a few months back and ran
into a group of guys I raced with 30 years ago -- including a guy who
was a junior prodigy back in the '70s and was in USCF development
camps with Andy Hampsten and Greg LeMond. He's now CEO of a national
company. We just rode along, nobody trying to prove anything, talking
about the good old days. My regular cohort is like that too, except we
do race each other at very predictable points in the ride. I'm
slowing, so my place is no longer assured. I've learned to be more
strategic, and my friends have learned to wait.



Too much competitiveness is why I didn't like riding with Dutch groups
back in my younger days. The Belgian groups were much more casual. They
let me join in when I came upon them even though I didn't wear cycling
clothes. When one of them spotted a good pub he hollered and everyone
followed him there. Occasionally the guys with two bottle holders had a
demi-bouteille of red wine in the 2nd one and let that circle around.


FWIW, a local mountain biker was found dead on some very tame single
track a few days ago. I didn't know him, but have friends who did. They
described him as middle aged (much younger than me), in tremendous
physical shape, built like a muscular swimmer, very low body fat, a
regular user of the YMCA etc.

Given the location, he probably wasn't pushing anywhere close to cardio
extremes. Indications are he was JRA and died instantly.

Apparently there is a correlation between long history as an endurance
athlete and atrial fibrillation and other electrical problems. Grant
Peterson has written about what he calls good exercise and bad exercise.
My views have certainly changed.


Redlining anything a lot isn't healthy, whether it is a combustion
engine or a heart. However, sometimes it's just bad luck or genes. I
knew a guy in Norway who walked almost everywhere instead of driving,
without pushing himself. He had a very healthy lifestyle, good food, no
booze, no smoking. One day in his mid 40's he didn't arrive after hiking
across a forest path, cardiac arrest.

--
Regards, Joerg

http://www.analogconsultants.com/
  #377  
Old November 16th 17, 12:17 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,609
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-14 17:31, John B. wrote:
On Tue, 14 Nov 2017 16:31:21 -0800, Joerg
wrote:

On 2017-11-14 16:06, John B. wrote:
On Tue, 14 Nov 2017 12:43:41 -0800, Joerg
wrote:

On 2017-11-13 19:04, Frank Krygowski wrote:
On 11/13/2017 7:09 PM, Joerg wrote:
On 2017-11-13 15:53, John B. wrote:
On Mon, 13 Nov 2017 10:10:05 -0800, Joerg
wrote:

On 2017-11-12 17:46, John B. wrote:

[...]


As an aside, I just measured the front discs on my wife's Honda Jazz
(I think it is called a "Fit"in the U.S.) and to my horror I find that
they are only 240mm (9.4") in diameter. As the nominal weight of the
car is about 1100 Kg (2400lb), as opposed to (probably) an all up
weight of less then 250 lbs for a bicycle, it is obvious that they
can't possibly be large enough to be safe. And Horrors, there isn't
any room to fit larger :-(


Of course, you didn't bother to measure the rotor thickness and didn't
notice the fact that it is rather solid.

Whatever are you talking about? Does the thickness of the disc matter?


sigh

I thought you were an engineer. No, I am not going to answer this
because it should be easy to figure that out for yourself.


If so why are bicycle (and motorcycle) disc such puny little things
hardly thicker then a piece of paper?


Have you ever wondered why a motorcycle rotor weighs over a pound?

https://i2.wp.com/www.yamahar3racing...9/IMG_4199.jpg


Now _that_ would be the dream for the front wheel of my MTB.

So why aren't you using it? I thought you were an engineer.


For the umpteenth time:

1. I don't have a lathe and other tools.

2. It requires adapting the fork mounts to a motorcycle caliper and the
handle has to come from a Yamaha.


Why ever so? After all you used adapters to mount your New! Big!
discs. Why can't you do exactly the same thing to mount the brakes on
the other side of the fork tube?


Requires total fork disassembly and aluminum welding, neither of which I
feel qualified to do or have the tools. Gets expensive if hired out.

Why welding? From what you wrote the forks have an existing mount for
the brakes. All you have to do is make a mounting that moves the
caliper to the front of the fork tube. A relatively simple design. See
https://www.youtube.com/watch?v=emW7M-ZD0Pw


You said other side of the fork.

Anyhow, there are numerous issues here, not the least being that it is
tough to mount a thick rotor so it still lines up correctly. It may be
possible to machine a part to adapt a motorcycle caliper and I have had
parts machined for my MTB. Requires time though. As I said, first I am
going to see if the 8" rotors are good enough which they very well may
be. 6" in back was clearly not adequate.


3. I just don't have that much time right now. For example, this
afternoon I get to modify an RF amp from my EMC set-up where the
rechargeable battery size has become unobtanium. Not my favorite job but
as John Wayne said "Man's got to do what man's got to do".

4. I just converted the MTB to 8" rotors for both wheels. Any engineer
woth his salt will recognize when good enough is good enough. I shall

^^^^^^^^
try that out extensively but I think that'll do the trick.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^


Sorry about that. Any Engineer worth is salt will recognize that using
larger discs may improve braking but no engineer worth is salt would
accept that as a fact with extensive testing.


When do you start reading more carefully before blurting out stuff that
makes no sense? I have underlined the salient section.


BTW, #2 wouldn't be so bad because that would eliminate the dreaded
(messy) burping procedure. Bike brake systems have no extra reservoir
tank for whatever reason.

What is next? The adapting of a motorcycle brake cylinder and lever to
a bicycle and the claim that it is better?



Possibly some day when I can retire some more. Today I had to fix
equipment in my electronics lab, needed to be able to do my job. That's
done. Now on to preparing the beer bottling for tomorrow. It'll be a
Belgian Saison and a Session Ale. Two other beers will be racked off to
secondary. Harvest trub for a bread, knead the dough, bake over wood
fire. Got to squeeze in a brew days as well and, of course, a riding
day. Then nursing home visits, preparing for continuing education
teaching, schedule ushers and greeters at church for the next quarter,
paint the deck underneath, and so on. See why there is only little time
left? :-)


Certainly. You simply considering making and consuming beer as more
important then cycling. Nothing wrong with that although some might
consider you a drunkard.


Then they have no clue about homebrewing or tend towards prejudice. It
is meant to be enjoyed with friends and in moderation.


But spending the public's taxes on building bike-ways for drunks on
bicycles might be a bit more then most politicians might be willing to
underwrite :-)



Are you prejudiced as well? I never ride drunk.

I pay enough taxes to expect something in return. And yes, that includes
road taxes. $4k alone in property taxes, part of which goes towards
traffic infrastructure. The issue is whether a community is willing to
invest in healthy modes of transportation. Ours is not, Folsom toward
the west of us is. It's that simple.

--
Regards, Joerg

http://www.analogconsultants.com/
  #378  
Old November 16th 17, 01:45 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,549
Default Why do some forks and frames have brake rotor size limits?


On Wed, 15 Nov 2017 15:17:28 -0800, Joerg
wrote:

On 2017-11-14 17:31, John B. wrote:
On Tue, 14 Nov 2017 16:31:21 -0800, Joerg
wrote:

On 2017-11-14 16:06, John B. wrote:
On Tue, 14 Nov 2017 12:43:41 -0800, Joerg
wrote:

On 2017-11-13 19:04, Frank Krygowski wrote:
On 11/13/2017 7:09 PM, Joerg wrote:
On 2017-11-13 15:53, John B. wrote:
On Mon, 13 Nov 2017 10:10:05 -0800, Joerg
wrote:

On 2017-11-12 17:46, John B. wrote:

[...]


As an aside, I just measured the front discs on my wife's Honda Jazz
(I think it is called a "Fit"in the U.S.) and to my horror I find that
they are only 240mm (9.4") in diameter. As the nominal weight of the
car is about 1100 Kg (2400lb), as opposed to (probably) an all up
weight of less then 250 lbs for a bicycle, it is obvious that they
can't possibly be large enough to be safe. And Horrors, there isn't
any room to fit larger :-(


Of course, you didn't bother to measure the rotor thickness and didn't
notice the fact that it is rather solid.

Whatever are you talking about? Does the thickness of the disc matter?


sigh

I thought you were an engineer. No, I am not going to answer this
because it should be easy to figure that out for yourself.


If so why are bicycle (and motorcycle) disc such puny little things
hardly thicker then a piece of paper?


Have you ever wondered why a motorcycle rotor weighs over a pound?

https://i2.wp.com/www.yamahar3racing...9/IMG_4199.jpg


Now _that_ would be the dream for the front wheel of my MTB.

So why aren't you using it? I thought you were an engineer.


For the umpteenth time:

1. I don't have a lathe and other tools.

2. It requires adapting the fork mounts to a motorcycle caliper and the
handle has to come from a Yamaha.


Why ever so? After all you used adapters to mount your New! Big!
discs. Why can't you do exactly the same thing to mount the brakes on
the other side of the fork tube?


Requires total fork disassembly and aluminum welding, neither of which I
feel qualified to do or have the tools. Gets expensive if hired out.

Why welding? From what you wrote the forks have an existing mount for
the brakes. All you have to do is make a mounting that moves the
caliper to the front of the fork tube. A relatively simple design. See
https://www.youtube.com/watch?v=emW7M-ZD0Pw


You said other side of the fork.


Yes I did and just like your argument that because the Germans did
something lit was a good idea, I was offering the you tube simply to
illustrate that it was a possible solution you your problem.

In fact, if I remember correctly, the guy does mention problems with
finding the proper mount brackets.

Anyhow, there are numerous issues here, not the least being that it is
tough to mount a thick rotor so it still lines up correctly. It may be
possible to machine a part to adapt a motorcycle caliper and I have had
parts machined for my MTB. Requires time though. As I said, first I am
going to see if the 8" rotors are good enough which they very well may
be. 6" in back was clearly not adequate.


Good Lord! A disc is just about the simplest thing that you could
design - two circles one inside the other - and almost the simplest
thing to manufacturer. Even in the wilds of California you should be
able to find either a "home machinist" or a commercial shop to make
them to your specifications.



3. I just don't have that much time right now. For example, this
afternoon I get to modify an RF amp from my EMC set-up where the
rechargeable battery size has become unobtanium. Not my favorite job but
as John Wayne said "Man's got to do what man's got to do".

4. I just converted the MTB to 8" rotors for both wheels. Any engineer
woth his salt will recognize when good enough is good enough. I shall
^^^^^^^^
try that out extensively but I think that'll do the trick.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^


Sorry about that. Any Engineer worth is salt will recognize that using
larger discs may improve braking but no engineer worth is salt would
accept that as a fact with extensive testing.


When do you start reading more carefully before blurting out stuff that
makes no sense? I have underlined the salient section.


BTW, #2 wouldn't be so bad because that would eliminate the dreaded
(messy) burping procedure. Bike brake systems have no extra reservoir
tank for whatever reason.

What is next? The adapting of a motorcycle brake cylinder and lever to
a bicycle and the claim that it is better?


Possibly some day when I can retire some more. Today I had to fix
equipment in my electronics lab, needed to be able to do my job. That's
done. Now on to preparing the beer bottling for tomorrow. It'll be a
Belgian Saison and a Session Ale. Two other beers will be racked off to
secondary. Harvest trub for a bread, knead the dough, bake over wood
fire. Got to squeeze in a brew days as well and, of course, a riding
day. Then nursing home visits, preparing for continuing education
teaching, schedule ushers and greeters at church for the next quarter,
paint the deck underneath, and so on. See why there is only little time
left? :-)


Certainly. You simply considering making and consuming beer as more
important then cycling. Nothing wrong with that although some might
consider you a drunkard.


Then they have no clue about homebrewing or tend towards prejudice. It
is meant to be enjoyed with friends and in moderation.


But spending the public's taxes on building bike-ways for drunks on
bicycles might be a bit more then most politicians might be willing to
underwrite :-)



Are you prejudiced as well? I never ride drunk.

I pay enough taxes to expect something in return. And yes, that includes
road taxes. $4k alone in property taxes, part of which goes towards
traffic infrastructure. The issue is whether a community is willing to
invest in healthy modes of transportation. Ours is not, Folsom toward
the west of us is. It's that simple.


Ah, but a much healthier means of transportation is a far simpler
method that doesn't even require special paths. Just get up on your
hind legs and walk.

Assuming a normal healthy individual you should be able to march (even
with a can of beer in your pocket) at about 3 miles per hour - about 5
kph - for hours on end.

I can assure you that a 5 Km stroll is far more invigorating then a 5
Km ride on a bicycle.
--
Cheers,

John B.

  #379  
Old November 16th 17, 02:26 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,549
Default Why do some forks and frames have brake rotor size limits?

On Wed, 15 Nov 2017 14:20:32 -0500, Frank Krygowski
wrote:

On 11/14/2017 11:08 PM, jbeattie wrote:
On Tuesday, November 14, 2017 at 4:41:22 PM UTC-8, Joerg wrote:
On 2017-11-14 16:15, jbeattie wrote:
On Tuesday, November 14, 2017 at 12:37:35 PM UTC-8, Joerg wrote:
On 2017-11-13 19:02, Frank Krygowski wrote:
On 11/13/2017 7:03 PM, Joerg wrote:

[...]

They just don't want to ride.

This is true. Again, we're an unusual group. If you gave every
American a perfectly safe, absolutely level, completely separated
bike path directly from their house to their favorite grocery
store one mile away, I doubt more than 3% would ride bikes to
shop.


They would if you gave them an E-bike with a throttle-only mode.
And if it had an A/C button.

I'm dealing with an infestation of eBikes. Some woman dropped me like
a rock last night on the latest Trek super-commuter eBike while
wearing the most expensive, fully reflective Showers Pass rain
jacket.


Spandex would have been nicer if she was pretty :-)

But yeah, same here on Sunday heading up a rail trail with a buddy. We
aren't slowpokes but then we heard a whirring from behind ... zzzooom
... a guy in his 70's shot past us on an E-bike. He didn't wear fancy
clothes though.


https://www.showerspass.com/collecti...nt=27454486405
In combination with her super-bright lights, she was a human flare --
and an expensive one. She could have gotten the same dollar-to-lumen
ratio by burning $20 bills. I want all that stuff! It was he
https://tinyurl.com/y7fgaymx The "flat" route home. I was on the
better paved section to the right going up.


You guys need someone to fix those roads. A few more winters and the
underlayment is toast, meaning it can't be patched anymore.


I can't hang with the eBikes through the hills -- not without giving
myself a heart attack, and although death is part of my long-term
financial plan, I'm saving it for later.


Some guys are pushing it too far. I passed a rider last week on a hill,
probably about 65, somewhat obese but lots of leg muscles. That didn't
sit well with him so he passed me and really stepped on it, telling me
"It's on, mate!". I decided not to give chase because he was really fast
and I carried some load. Up the hill where it leveled off I closed up
quickly and he looked totally exhausted. That can't be good.


"It's on mate"(?) What a dope. I would have gone out and bought an old Silca frame pump just so I could stick it in his front wheel. "Hey, wait here; I'll be right back." I pass people all the time and couldn't imagine saying "It's on mate." I'd sign up for Death with Dignity if I did that sort of thing.

Totally OT, but I was riding up on Skyline a few months back and ran into a group of guys I raced with 30 years ago -- including a guy who was a junior prodigy back in the '70s and was in USCF development camps with Andy Hampsten and Greg LeMond. He's now CEO of a national company. We just rode along, nobody trying to prove anything, talking about the good old days. My regular cohort is like that too, except we do race each other at very predictable points in the ride. I'm slowing, so my place is no longer assured. I've learned to be more strategic, and my friends have learned to wait.


FWIW, a local mountain biker was found dead on some very tame single
track a few days ago. I didn't know him, but have friends who did. They
described him as middle aged (much younger than me), in tremendous
physical shape, built like a muscular swimmer, very low body fat, a
regular user of the YMCA etc.

Given the location, he probably wasn't pushing anywhere close to cardio
extremes. Indications are he was JRA and died instantly.

Apparently there is a correlation between long history as an endurance
athlete and atrial fibrillation and other electrical problems. Grant
Peterson has written about what he calls good exercise and bad exercise.
My views have certainly changed.


As you say, there seems to be some correlation between endurance
athletes and some heart problems, but at the same time some endurance
athletes seem to just go on for ever. "Old" John Kelly ran something
like 61 Boston Marathons, his last at the age of 84, In his 70's he
was still running 50 miles a week and some 15 races a year, while
"Young" John Kelly (the family name "Kelly" is not a rare one in South
Boston :-) ran 31 B.M.'s his last at 62 in 4:07.

On the other hand
https://www.peakendurancesport.com/e...urance-sports/
says:
"Endurance athletes who exercise for three hours or more have an
increased chance of dying from a cardiac arrest. About 1 in 50,000: if
you run marathons or participate in other forms of exercise which last
for three hours or more."

They also say the "For one thing, it's clear that regular exercise
protects you from heart attacks over broad time frames; for example,
over the course of a year regular exercisers will have fewer cardiac
failures than their sedentary counterparts.

And they go on to say that "If you are having second thoughts about
running marathons, you should know that the previously quoted rate of
one death per 50,000 marathon runners might be a bit high. For
example, there is evidence that in male runners aged 30-64 who have
not been diagnosed with heart disease, there is approximately one
death for each 800,000 person-hours of running or jogging"

And even more enlightening they add "Expressing the 800,000 statistic
in a different way, we can say that healthy, middle-aged males who run
for one hour each day can expect to die while running once every 2,192
years (800,000 hours divided by 365 hours of running per year = 2,192
years). By the same token, individuals who run two hours per day
should die while running about once every 1,096 years. When the risks
are seen in this light, many endurance athletes will consider them
acceptably low, especially as the general risk of heart disease is
reduced by strenuous training."

I think that some exercise is far better then no exercise and I think
I'll carry on as best I can :-)
--
Cheers,

John B.

  #380  
Old November 16th 17, 05:00 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 5,392
Default Why do some forks and frames have brake rotor size limits?

On 11/15/2017 7:45 PM, John B. wrote:

On Wed, 15 Nov 2017 15:17:28 -0800, Joerg
wrote:

Anyhow, there are numerous issues here, not the least being that it is
tough to mount a thick rotor so it still lines up correctly. It may be
possible to machine a part to adapt a motorcycle caliper and I have had
parts machined for my MTB. Requires time though. As I said, first I am
going to see if the 8" rotors are good enough which they very well may
be. 6" in back was clearly not adequate.


Good Lord! A disc is just about the simplest thing that you could
design - two circles one inside the other - and almost the simplest
thing to manufacturer. Even in the wilds of California you should be
able to find either a "home machinist" or a commercial shop to make
them to your specifications.


This guy may be for hi
https://www.youtube.com/watch?v=VVV4xeWBIxE

He has lots of videos. I think one even involves repairing a chain
without a chain tool.

--
- Frank Krygowski
 




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