"Actually you are the first person to bring up this issue"

Chris B. wrote:

"Just zis Guy, you know?" wrote:

"Chris Malcolm" wrote:

Since most bike brakes are capable of skidding the front wheel in most
circs, all that better brakes give you is finer control of braking
force and less grip effort.

And less fade.

Why?

Brake fade is bad. If brakes give you less of it, it follows that they are
better, all else being equal.

I assume Chris Malcolm wasn't including dry pavement when he said "most
bike brakes are capable of skidding the front wheel in most circs". On dry
pavement the limiting factor is nearly always geometry rather than traction
or "brake power".

--
Benjamin Lewis

F u cn rd ths u cnt spl wrth a dm!

Chris B. wrote:

"Just zis Guy, you know?" wrote:

"Chris Malcolm" wrote:

Since most bike brakes are capable of skidding the front wheel in most
circs, all that better brakes give you is finer control of braking
force and less grip effort.

And less fade.

Why?

Brake fade is bad. If brakes give you less of it, it follows that they are
better, all else being equal.

I assume Chris Malcolm wasn't including dry pavement when he said "most
bike brakes are capable of skidding the front wheel in most circs". On dry
pavement the limiting factor is nearly always geometry rather than traction
or "brake power".

--
Benjamin Lewis

F u cn rd ths u cnt spl wrth a dm!

On Mon, 29 Mar 2004 12:53:42 -0800, Benjamin Lewis
wrote:

Chris B. wrote:

"Just zis Guy, you know?" wrote:

"Chris Malcolm" wrote:

Since most bike brakes are capable of skidding the front wheel in most
circs, all that better brakes give you is finer control of braking
force and less grip effort.

And less fade.

Why?

Brake fade is bad. If brakes give you less of it, it follows that they are
better, all else being equal.

I agree but the implication was that disc brakes are more fade
resistant (all of the other points Guy mentioned were positive traits
of disc brakes), although this isn't clear by looking at the quoted
section. No doubt Guy will clarify if he was instead referring to rim
brakes. Again, I often hear that disc brakes are less prone to fade
resistant and I wonder if it is true and why.

On Mon, 29 Mar 2004 12:53:42 -0800, Benjamin Lewis
wrote:

Chris B. wrote:

"Just zis Guy, you know?" wrote:

"Chris Malcolm" wrote:

Since most bike brakes are capable of skidding the front wheel in most
circs, all that better brakes give you is finer control of braking
force and less grip effort.

And less fade.

Why?

Brake fade is bad. If brakes give you less of it, it follows that they are
better, all else being equal.

I agree but the implication was that disc brakes are more fade
resistant (all of the other points Guy mentioned were positive traits
of disc brakes), although this isn't clear by looking at the quoted
section. No doubt Guy will clarify if he was instead referring to rim
brakes. Again, I often hear that disc brakes are less prone to fade
resistant and I wonder if it is true and why.

On Mon, 29 Mar 2004 21:17:54 GMT, Chris B.
wrote:

snip

Sorry, that should read "I often hear that disc brakes are less prone
to fade and I wonder if it is true and why."

On Mon, 29 Mar 2004 21:17:54 GMT, Chris B.
wrote:

snip

Sorry, that should read "I often hear that disc brakes are less prone
to fade and I wonder if it is true and why."

Chris B. wrote:

On Mon, 29 Mar 2004 12:53:42 -0800, Benjamin Lewis
wrote:

Chris B. wrote:

"Just zis Guy, you know?" wrote:

"Chris Malcolm" wrote:

Since most bike brakes are capable of skidding the front wheel in
most circs, all that better brakes give you is finer control of
braking force and less grip effort.

And less fade.

Why?

Brake fade is bad. If brakes give you less of it, it follows that they
are better, all else being equal.

I agree but the implication was that disc brakes are more fade
resistant (all of the other points Guy mentioned were positive traits
of disc brakes), although this isn't clear by looking at the quoted
section. No doubt Guy will clarify if he was instead referring to rim
brakes. Again, I often hear that disc brakes are less prone to fade
resistant and I wonder if it is true and why.

I see -- your question was a little unspecific. It would surprise me to
find that disc brakes were less prone to fade, since they appear to have
much less surface area available for heat dissipation, but there may be
other factors I'm overlooking. They certainly must reduce the chances of
tire blow-off due to heating of rims, but this is a different question.

--
Benjamin Lewis

F u cn rd ths u cnt spl wrth a dm!

Chris B. wrote:

On Mon, 29 Mar 2004 12:53:42 -0800, Benjamin Lewis
wrote:

Chris B. wrote:

"Just zis Guy, you know?" wrote:

"Chris Malcolm" wrote:

Since most bike brakes are capable of skidding the front wheel in
most circs, all that better brakes give you is finer control of
braking force and less grip effort.

And less fade.

Why?

Brake fade is bad. If brakes give you less of it, it follows that they
are better, all else being equal.

I agree but the implication was that disc brakes are more fade
resistant (all of the other points Guy mentioned were positive traits
of disc brakes), although this isn't clear by looking at the quoted
section. No doubt Guy will clarify if he was instead referring to rim
brakes. Again, I often hear that disc brakes are less prone to fade
resistant and I wonder if it is true and why.

I see -- your question was a little unspecific. It would surprise me to
find that disc brakes were less prone to fade, since they appear to have
much less surface area available for heat dissipation, but there may be
other factors I'm overlooking. They certainly must reduce the chances of
tire blow-off due to heating of rims, but this is a different question.

--
Benjamin Lewis

F u cn rd ths u cnt spl wrth a dm!

carlfogel wrote:
Dear Jobst,
I can't make the angles work out as you suggest.
In fact, an upright seems to have a steeper and less effective braking
angle from center of gravity to contact patch, 61 degrees versus 54
degrees for the recumbent.
Here's how I tried to figure the angles. I gather that the ratio of the
adjacent (longer) to the opposite (shorter) legs of a right triangle
should give the tangent of the angle that I want.
http://www.ransbikes.com/2004Bikes/Rocket.htm
When I measure things for the recumbent from where I expect the belly
button to be to the contact patch, I get a right triangle with an
adjacent side of about 75mm on my screen and an opposite side of 55mm.
(If anything, the center of gravity should be further back than the
navel, given the rider's reclining position.)
With 75/55 = 1.3636, my tangent-angle lookup shows an angle of about
54 degrees.
When I look at "Bicycling Science" 2nd edition and do the same thing for
figure 8.6 (the upright bike with numerous details and an indicated
center of gravity, page. 197), I get a 45-inch adjacent side and a 25-
inch opposite side, 45/25= 1.8, and my tangent-angle lookup says about
61 degrees.
Here's the corrected address for the blue trike:
http://www.ihpva.org/incoming/2002/dragonflyer/df1a.jpg
Carl Fogel


Dear Jobst

Aaaargh! My mother won't let me out without my mittens on strings.
capital D may be needed in "dragonflyer"

http://www.ihpva.org/incoming/2002/Dragonflyer/df1a.jp

Carl oFel


-

carlfogel wrote:
Dear Jobst,
I can't make the angles work out as you suggest.
In fact, an upright seems to have a steeper and less effective braking
angle from center of gravity to contact patch, 61 degrees versus 54
degrees for the recumbent.
Here's how I tried to figure the angles. I gather that the ratio of the
adjacent (longer) to the opposite (shorter) legs of a right triangle
should give the tangent of the angle that I want.
http://www.ransbikes.com/2004Bikes/Rocket.htm
When I measure things for the recumbent from where I expect the belly
button to be to the contact patch, I get a right triangle with an
adjacent side of about 75mm on my screen and an opposite side of 55mm.
(If anything, the center of gravity should be further back than the
navel, given the rider's reclining position.)
With 75/55 = 1.3636, my tangent-angle lookup shows an angle of about
54 degrees.
When I look at "Bicycling Science" 2nd edition and do the same thing for
figure 8.6 (the upright bike with numerous details and an indicated
center of gravity, page. 197), I get a 45-inch adjacent side and a 25-
inch opposite side, 45/25= 1.8, and my tangent-angle lookup says about
61 degrees.
Here's the corrected address for the blue trike:
http://www.ihpva.org/incoming/2002/dragonflyer/df1a.jpg
Carl Fogel


Dear Jobst

Aaaargh! My mother won't let me out without my mittens on strings.
capital D may be needed in "dragonflyer"

http://www.ihpva.org/incoming/2002/Dragonflyer/df1a.jp

Carl oFel


-