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



 
 
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  #361  
Old November 14th 17, 10:46 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,624
Default Why do some forks and frames have brake rotor size limits?

On 2017-11-14 13:00, Frank Krygowski wrote:
On 11/14/2017 3:43 PM, Joerg wrote:
On 2017-11-13 19:04, Frank Krygowski wrote:
On 11/13/2017 7:09 PM, Joerg wrote:

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.


I thought you were an engineer.


Yeah, electronics. Electronics guys don't have mills and lathes. Unless
they are not married ...

In the same way I could question your degree because you likely do not
have a spectrum analyzer and a network analyzer.


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


I thought you were an engineer.


See above.


3. I just don't have that much time right now.


You spend too much time whining on Usenet.


It's just minutes.


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.


Then why did you say " Now _that_ would be the dream for the front wheel
of my MTB" ?


Because it is.


I agree that any engineer worth his salt will recognize when good enough
is good enough.

Failing to do that is your entire schtick.


Wrong. Try buying this kind of rear end for a sull-suspension bike at
your LBS:

http://www.analogconsultants.com/ng/bike/Muddy4.JPG

This is certainly a "good enough" solution. Homebrew. Most offroad
motorcycles have that standard. Bicycles? Phhht ...

--
Regards, Joerg

http://www.analogconsultants.com/
Ads
  #362  
Old November 15th 17, 12:59 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,558
Default Why do some forks and frames have brake rotor size limits?

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.

  #363  
Old November 15th 17, 01:06 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,558
Default Why do some forks and frames have brake rotor size limits?

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?

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.

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?
--
Cheers,

John B.

  #364  
Old November 15th 17, 01:15 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 2,769
Default Why do some forks and frames have brake rotor size limits?

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:
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'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. 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.

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.

-- Jay Beattie.
  #365  
Old November 15th 17, 01:18 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,624
Default Why do some forks and frames have brake rotor size limits?

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.

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.

--
Regards, Joerg

http://www.analogconsultants.com/
  #366  
Old November 15th 17, 01:31 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,624
Default Why do some forks and frames have brake rotor size limits?

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.


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? :-)

--
Regards, Joerg

http://www.analogconsultants.com/
  #367  
Old November 15th 17, 01:41 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 4,624
Default Why do some forks and frames have brake rotor size limits?

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.

--
Regards, Joerg

http://www.analogconsultants.com/
  #368  
Old November 15th 17, 02:31 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,558
Default Why do some forks and frames have brake rotor size limits?

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


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.

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 :-)
--
Cheers,

John B.

  #369  
Old November 15th 17, 02:33 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,558
Default Why do some forks and frames have brake rotor size limits?

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?

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.

--
Cheers,

John B.

  #370  
Old November 15th 17, 02:43 AM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 9,031
Default Why do some forks and frames have brake rotor size limits?

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.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


 




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