Cantilever style booster for centerpulls?

In article said:

Ryan Cousineau said:

Quoted message said:

> The big negative for disc brakes is the failure mode and reliability when descending something
> like passes in the Alps where missing a hairpin turn is DEATH. It's a long way down. When you
> lose fluid or get even a tiny leak, it is serious trouble.

I should have put my original sarcastic paragraph here, where it would have made most sense. fluid
loss is bad, but the catastrophic failure mode on hydraulic brake systems is rare. Badly maintained
brake cables are in the same range of hazard, and about as acute-failure prone. Brake bleeding, pad
adjustment, and fluid levels all have to be checked, but if those things are ok when you leave the
workbench they'll probably be okay until you get back. Meanwhile, rim brakes have their own
troubles, mainly proper adjustment of pad position and cosine errors on many designs.

Quoted message said:

Quoted message said:

Quoted message said:

You don't even need a leak to have major brake failure with disks. The main problem,
safety-wise, is that they can overheat and "go away" very suddenly. Rim brakes' fade is much
more gradual, and when it does happen you still have some braking power left.

Quoted message said:

Quoted message said:

Rim brakes also cool off a lot faster -- usually in seconds. Disks get hotter and hotter, and
may take several minutes to cool down. And it's not just the rotors and pads that get hot, but
the calipers, oil, etc.

Quoted message said:

Goodness, all these dangerous discs! I'm glad nothing important like my car or motorcycle uses
these deadly brake types.

Stop wringing your hands. Bicycle disc brakes are not motor vehicle brakes and must compete in
weight and size to trivially simple caliper rim brakes. If you want to cite motorcycle brakes in
this context, I suggest you get some from a motorcycle shop and install them on your bicycle.

Motorcycles operate at (potentially) considerably greater speeds than bicycles, and they weigh more,
but the latest 8" bicycle discs are starting to look like some of the smaller dirt motorcycle gear.

Discs, usually being made of metal, cool down fairly quickly. Certainly most of the discs I have
seen shed heat quite efficiently, that being a key design goal of any braking system except the
stick-in-the-spokes technique.

Quoted message said:

Quoted message said:

PS: was I away when most bicycles stopped having two completely independent braking systems? Has
anyone here ever experienced complete brake failure, except maybe "I was riding a track bike
with no front brake, and..."?

I see, you haven't tried this but next time you are descending a mountain road, entering a sharp
turn, try using just the rear brake instead of the front one, in the last moment. I think you'll
see the light... maybe.

See the light? Try that and I'd be likely to head towards the light.

First, I'm a pretty cautious descender, and most of my serious brake use happens on dirt. I'm not
Jobst in either cycling habits or engineering background. That said, I don't have any motivation to
enter hairpin turn descents with enough speed that I will not be able to negotiate the turn if my
front brake fails catastrophically.

Second, unannounced catastrophic failures of any decent, current braking system, disc or rim based,
hydraulic or cable, are vanishingly rare. If they weren't, cycling would be a really dangerous
sport, and car-driving and motorcycling...well, okay, motorcycling is relatively dangerous, but it's
not because of brake failure. Discussing them as a serious argument pro or con any brake system
(except maybe "track bike with no lockring"😉 seems unreasonable. There is one exception, which is
the front-wheel pull-out effect for discs, but that is separate from the pros and cons of discs we
are discussing here, and remedies are reasonably well-known.

There is no good time for a brake to fail, but I'm not convinced that the failures of hydraulic and
disc systems are more frequent than those of rim and cable systems.

--
Ryan Cousineau, [email hidden] sfu.ca~rcousineOpen ↗ President, Fabrizio Mazzoleni Fan Club

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

Pete Cresswell said:

Quoted message said:

THAT'S something I've wondered about a long time, just why does an MTB need such powerfull
brakes? I can see why a tandem or a packed touring bike might, they have a lot more weight to
stop.

Quoted message said:

Quoted message said:

But they're stopping on asphault,

There are two problems here. One is that the terms power and force are not synonymous and one is
often confused with the other, as in this thread. You can have a brake that grabs and will stop
the front wheel with little hand lever force. You can also have a brake that will help you descend
steep terrain and dissipate power continuously. The first one might be better for many trail
applications, while the second is a necessity for descending steep paved mountain passes with many
curves that require braking.

No. Modulation on the trail is essential to prevent washout. My current bike went from center-pull
cantis to v-brakes front and rear to mechanical disk front, v-brake rear. I was never able to do
1-fingered "stoppies" with my center-pulls. Even with the v-brakes, this was a three-finger job.

Rim brakes do indeed "go away," over a long descent, and heat does build up in the rim/tire/tube
system. Sometimes enough to blow the tire off the rim (not to me, but to a riding partner.)

Disk brakes will never wear down your rim sidewall either. Replacing a rotor or pads is a trivial,
trailside task. (Not that you would do it there, but you *could.*) Heck, you can carry those things
along. It's tough to carry along an extra rim. 🙂

But that's an absurd example.

Quoted message said:

Quoted message said:

Seems to me like the braking power of any bike is limited more by the adhesion of the front tire
than anything in the brakes.

That would be braking force. Yes, road bicycles don't skid front wheels because they have better
traction on pavement than on a dirt road or trail, regardless of tread pattern.

This is where modulation is exceedingly important.

Quoted message said:

Quoted message said:

Having said that, the reasons I moved to hydraulic disc brakes on my MTB and cable discs on the
bike I use mainly for sort-of road riding are:

Quoted message said:

1) Modulation

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2) Tolerance of wobbly wheels

Quoted message said:

3) Tolerance of off-center wheels

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4) Rain reliability

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5) Mud-friendliness.

Quoted message said:

6) No chance of a mis-aligned pad taking out the sidewall after

riding away from > a crash (been there....)

Quoted message said:

7) Wheel interchangability between bikes (given that the MTB is going to have discs for sure,
but the "sort-of-road" bike started out with v-brakes and probably could have stayed that
way...

Quoted message said:

8) I like the sound the front brake makes when it's doing all the heavy lifting on a long
descent...(go figure....)

I don't see where any of the above reasons rule out rim brakes except for the rain.

And mud. With rim brakes, you can have quite a long "oh, [censored]" moment where you grab for brakes and
there just isn't anything except a scraping noise. Then the rim dries/ sheds mud, and you're
gripping too hard - BAM! Down you go. Done it several times, and then learned to drag the brakes
after a rim-dunking. Never have to think about it with a disk.

If you've ever taco'ed a wheel on the trail, then brought it back to some semblance of true to ride
out, it's nice to have a front brake.

Quoted message said:

Disc brakes have too little surface to dissipate power at the rate that rim brakes do, but that
will change as more people go to insulators for rims (aka carbon fiber).

The question is: Is the power dissipation rate adequate for the task? More than adequate, even on
very long downhills. I've turned my disk blue - and it never just "went away." But I was using
sintered pads. The organic kind might have melted under those conditions.

In any case - what's the mathematical difference between rims and disks? When it comes to braking,
my understanding is that swept area is the starting point of calculation.

Quoted message said:

Modulation, wobbly wheels, compatibility with hand-up wheels in a race, and "heavy lifting"? are
no better with discs than with rim brakes.

Uhh, modulation - are you speaking from experience, or engineering principles? I'd like to see
mathematical proof of how disks offer similar modulation to rim brakes. My experience tells me
different, but I will always bow to the unblinking logic of math.

Quoted message said:

The big negative for disc brakes is the failure mode and reliability when descending something
like passes in the Alps where missing a hairpin turn is DEATH.

Failure mode for mechaical disks is the same as for rim brakes.

Quoted message said:

It's a long way down. When you lose fluid or
get even a tiny leak, it is serious trouble.

Or if a cable pulls out of a stop. Or simply breaks. Good maintenance habits will eliminate these
concerns to a vanishingly small risk.

Quoted message said:

Besides, hydraulic and cable operated calipers both have a linear characteristic. Therefore,
modulation should be mainly a problems of adjustment, not whether it is a hydraulic or mechanical
transducer.

How much hand power can be transmitted by cable vs a well-designed hydraulic system? If the
input piston is large, and the output piston small, it seems like there might be some advantage
given there.

The elimination of the "oh, [censored]" moments is reason enough, although I don't think you know what
you're talking about when you dismiss "wheel wobble" and the brake pad/tire sidewall contact issues.
Maybe as they pertain to road bikes, but not mountain bikes.

Spider

Thanks, Jobst, for your previous answers. Been trying to digest that and been rereading Sheldon's
pages again. sheldonbrown.comcantilever geometry.htmlOpen ↗

Trying to improve on old technology I guess, but I like the look of centerpulls on an older bike and
the idea of brazing the pivots on intrigues me. I missed out on that whole era. In regard to
mechanical advantage: Wouldn't the shorter Weinmann's (610's) have a different MA than the longer
ones (750's)? The calipers seem to be the same above the pivots, all the added length is below the
pivots. Should they have compensated for this? Perhaps in the straddle cable length? Thanks.

Pete Geurds Douglassville, PA

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Quoted message said:

They would be a little less flexible but not much, the forces on the bridge being primarily tension
rather than bending. However, the centerpull brake has the same (but inverse) problem as the
cantilever in that its pad motion is at 45 degrees to the plane of the rim. As pads wear, the
centerpull climbs up into the tire while the cantilever goes the other way and dives under the rim.
In both cases (blown tire or pup under pads)cause a complete loss of control.

Brakes of that era all had the same mechanical advantage of 1:1 in the caliper or cantilever, while
the hand lever had a 4:1 ratio. With the advent of the dual pivot caliper, that allowed reducing
pad clearance, with its forced pad centering, hand levers have changed to a higher mechanical
advantage of about 5.6:1.

Historically the centerpull was one of those ideas that came about through a misunderstanding of
the advantage of the single pivot "side pull" of the day. That side pull, the Campagnolo Record,
required no adjustment for the life of the pad down to the metal. In geometry, that is called
"cosine error". Sweeping a lever through small angles around zero causes essentially no change in
the line of action. In contrast, the dual pivot has large "sine error" on the short arm extending
from the offset pivot (the dual pivot). The solution to this is to offer brake pads with so little
rubber that they cannot be worn down much before replacement and therefore need not be adjusted...
just replaced.

Pete Geurds Douglassville, PA

Spider at [email hidden] wrote on 4/23/03 8:58 AM:>

Quoted message said:

No. Modulation on the trail is essential to prevent washout. My current bike went from center-pull
cantis to v-brakes front and rear to mechanical disk front, v-brake rear. I was never able to do
1-fingered "stoppies" with my center-pulls. Even with the v-brakes, this was a three-finger job.

In this context, it seems you are speaking about lever force, which is not the same as modulation.
What you are saying is that it's easier to apply maximal braking force. That's not the same as
modulation.

Quoted message said:

Quoted message said:

<jobst's> That would be braking force. Yes, road bicycles don't skid front wheels because they
have better traction on pavement than on a dirt road or trail, regardless of tread pattern.

This is where modulation is exceedingly important.

Huh?

Quoted message said:

I see, you haven't tried this but next time you are descending a mountain road, entering a sharp
turn, try using just the rear brake instead of the front one, in the last moment. I think you'll
see the light... maybe.

There seems to be some apples vs. oranges misunderstanding in this thread, AFAIC. Descending paved
roads on a road bike and negotiating steep technical dirt/rock/root trails on a mountain bike are
two different animals. I use different brakes and different braking technique depending on what I'm
riding where.

On the road, I use a front rim brake for 95% of my stopping, just as
Mr. Brown suggests. sheldonbrown.combrakturn.htmlOpen ↗ I rarely need anything else.

Off-road, I've moved from cantis circa 1990, to V-s circa 1995, to discs front and rear circa 2001.
Cantis did not have stopping power needed for really steep terrain and technical descending. V-s had
superior stopping power but less modulation. Discs have both better than the sum of the other two,
and anybody who rides off road more than casually (except for hard core racers, so far at least)
won't settle for less.

Plus, the rear brake is a much more necessary tool off road.

As Sheldon says regarding rear braking for road riding:

"Skilled cyclists use the front brake alone probably 95% of the time, but there are instances when
the rear brake is preferred:

Slippery surfaces. On good, dry pavement, it is generally impossible to skid the front wheel by
braking. On slippery surfaces, however it is possible to do so. It is nearly impossible to recover
from a front wheel skid, so if there is a high risk of skidding, you're better off controlling your
speed with the rear brake.

Bumpy surfaces. On rough surfaces, your wheels may actually bounce up into the air. If there is a
chance of this, don't use the front brake. If you apply the front brake while the wheel is airborne,
it will stop, and coming down on a stopped front wheel is a Very Bad Thing."

Add in steep hills and drop offs (anybody who has endo'd grabbing a load off front brake dropping
onto a ledge knows this) and you have described off-road riding.

Again, apples and oranges. --dt

Pete Geurds said:

Quoted message said:

They would be a little less flexible but not much, the forces on the bridge being primarily
tension rather than bending. However, the centerpull brake has the same (but inverse) problem as
the cantilever in that its pad motion is at 45 degrees to the plane of the rim. As pads wear, the
centerpull climbs up into the tire while the cantilever goes the other way and dives under the
rim. In both cases (blown tire or pup under pads)cause a complete loss of control.

Quoted message said:

Quoted message said:

Brakes of that era all had the same mechanical advantage of 1:1 in the caliper or cantilever,
while the hand lever had a 4:1 ratio. With the advent of the dual pivot caliper, that allowed
reducing pad clearance, with its forced pad centering, hand levers have changed to a higher
mechanical advantage of about 5.6:1.

Oops! Make that "Calipers have changed to a 1.4:1 ratio giving the
5.6:1 ratio at the hand lever."

Quoted message said:

Quoted message said:

Historically the centerpull was one of those ideas that came about through a misunderstanding of
the advantage of the single pivot "side pull" of the day. That side pull, the Campagnolo Record,
required no adjustment for the life of the pad down to the metal. In geometry, that is called
"cosine error". Sweeping a lever through small angles around zero causes essentially no change in
the line of action. In contrast, the dual pivot has large "sine error" on the short arm extending
from the offset pivot (the dual pivot). The solution to this is to offer brake pads with so
little rubber that they cannot be worn down much before replacement and therefore need not be
adjusted... just replaced.

Quoted message said:

Trying to improve on old technology I guess, but I like the look of centerpulls on an older bike
and the idea of brazing the pivots on intrigues me. I missed out on that whole era. In regard to
mechanical advantage: Wouldn't the shorter Weinmann's (610's) have a different MA than the longer
ones (750's)? The calipers seem to be the same above the pivots, all the added length is below the
pivots. Should they have compensated for this? Perhaps in the straddle cable length?

I think you'll find the length ratio between pivot to cable anchor and pivot to brake pad central
position (in the slot) to be 1:1. The centerpull is more obscure, especially if the straddle cable
has an optional length as it often does with a cantilever brake. The intent at that time was 1:1 for
the athletes for whom they were designed.

The higher mechanical advantage came about as more "racing" bicycles were used by avocational
bicyclists who did not have the strength in two (middle and index) fingers to stop the front wheel
for sudden stops or descending fast on steep curvy roads. Bicycle shops regularly told owners of
expensive bicycles with Campagnolo Record brakes the excuse that these brakes were meant to control
speed for racers, rather than for stopping. I heard that one often. The racer just has stronger
hands and needs to stop at least as quickly as any tourist.

The reason brakes didn't come with a higher mechanical advantage was as I explained, pad clearance
and centering.

Another brake item worth considering:

draco.acs.uci.edu9.36.htmlOpen ↗

Jobst Brandt [email hidden] Palo Alto CA

Jim Edgar said:

Quoted message said:

Quoted message said:

That would be braking force. Yes, road bicycles don't skid front wheels because they have better
traction on pavement than on a dirt road or trail, regardless of tread pattern.

Quoted message said:

Quoted message said:

This is where modulation is exceedingly important.

Quoted message said:

Huh?

The Campagnolo Delta was a brake that did not modulate well because it had a variable mechanical
advantage that went into lockup as its stroke increased (as pads wore). If a brake does not modulate
well it can pitch the rider over the bars, but before that, washing out on a descending curve is
more likely.

tinyurl.coma8zsOpen ↗

That is an example of modulation.

Jobst Brandt [email hidden] Palo Alto CA

Jim Edgar said:

Spider at [email hidden] wrote on 4/23/03 8:58 AM:>

Quoted message said:

No. Modulation on the trail is essential to prevent washout. My current bike went from
center-pull cantis to v-brakes front and rear to mechanical disk front, v-brake rear. I was never
able to do 1-fingered "stoppies" with my center-pulls. Even with the v-brakes, this was a
three-finger job.

In this context, it seems you are speaking about lever force, which is not the same as modulation.
What you are saying is that it's easier to apply maximal braking force. That's not the same as
modulation.

In fact, it's pretty much the opposite. A brake with good modulation will require a considerably
different amount of force between the "stopping quickly" and "over the bars" points. That's what I
miss most about my old cantis - I could get right to - but not beyond - the "edge" with ease. With
my current linar pull brake, I have to stay away from that "edge" (it bites chunks out of me now!).

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

In article said:

Jim Edgar said:

Spider at [email hidden] wrote on 4/23/03 8:58 AM:>

Quoted message said:

No. Modulation on the trail is essential to prevent washout. My current bike went from
center-pull cantis to v-brakes front and rear to mechanical disk front, v-brake rear. I was
never able to do 1-fingered "stoppies" with my center-pulls. Even with the v-brakes, this was a
three-finger job.

In this context, it seems you are speaking about lever force, which is not the same as modulation.
What you are saying is that it's easier to apply maximal braking force. That's not the same as
modulation.

In fact, it's pretty much the opposite. A brake with good modulation will require a considerably
different amount of force between the "stopping quickly" and "over the bars" points. That's what I
miss most about my old cantis - I could get right to - but not beyond - the "edge" with ease. With
my current linar pull brake, I have to stay away from that "edge" (it bites chunks out of me now!).

OK, so why are you still using v-brakes? It's not like cantilevers are hard to find!

--Paul

"Paul Southworth" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

That's what I miss

Quoted message said:

most about my old cantis - I could get right to - but not beyond - the "edge" with ease. With my
current linar pull brake, I have to stay away from that "edge" (it bites chunks out of me now!).

OK, so why are you still using v-brakes? It's not like cantilevers are hard to find!

But compatible (new) frames are.

Doug Taylor said:

"Paul Southworth" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

That's what I miss

Quoted message said:

most about my old cantis - I could get right to - but not beyond - the "edge" with ease. With my
current linar pull brake, I have to stay away from that "edge" (it bites chunks out of me now!).

OK, so why are you still using v-brakes? It's not like cantilevers are hard to find!

But compatible (new) frames are.

Not when you build them yourself, right Mark?

Jon Bond

[email hidden] wrote in message

Quoted message said:

tinyurl.coma8zsOpen ↗

That is an example of modulation.

I've been following rbt for about a year now, and this image is firmly burned into my long term
memory. i could swear ive seen it used to demonstrate the capabilities of smooth tread, lean angles,
braking in turns, impressive cornering ability, and now 'modulation' again.

From now on, no web link is necessary. I am sure that everyone has it bookmarked, or more likely-
saved as the background image on their desktop.

perhaps mr. brandt could have a new updated photo taken, to provide some variety.

<intended in good humor>

anthony

Doug Taylor said:

Off-road, I've moved from cantis circa 1990, to V-s circa 1995, to discs front and rear circa 2001.
Cantis did not have stopping power needed for really steep terrain and technical descending.

This doesn't make sense. On a steep descent, it is easier to lift the back wheel - the maximum
deceleration that can be applied by brakes is less.

[I presume you don't mean a steep ascent, since I rarely find that stopping on a steep ascent is a
problem. :-]
--
David Damerell <[email hidden]> Kill the tomato!

Ryan Cousineau said:

PS: was I away when most bicycles stopped having two completely independent braking systems? Has
anyone here ever experienced complete brake failure, except maybe "I was riding a track bike
with no front brake, and..."?

Oh, yes. This was many years ago, before mountain bikes were around. I was riding my Raleigh with
the three speed hub on a bridle trail and managed to have three of the four brake pads shake out.
Without my noticing, of course, until I was on a downhill section.

I was able to grab at saplings and bushes enough to slow down and stop, then walked the bike back to
the road and to where I could get some new pads.

mike

--
Mike Fischbein [email hidden] Any opinions expressed are mine and not necessarily those of any other
entity. They may not even be mine.

Jonathan Bond said:

Doug Taylor said:

"Paul Southworth" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

That's what I miss

>most about my old cantis - I could get right to - but not beyond - the "edge" with ease. With my
>current linar pull brake, I have to stay away from that "edge" (it bites chunks out of me now!).

OK, so why are you still using v-brakes? It's not like cantilevers are hard to find!

But compatible (new) frames are.

Not when you build them yourself, right Mark?

True (and the reason I'm still running canti brakes on the back - a great idea for anyone since rear
V-brakes tend to be on/off brakes where I ride).

The problem is that it's nearly impossible to find a suspension fork that's set up for canti brakes.
My last "upgrade" forced me into a V-brake mode and I've missed my cantis ever since.

I should point out for those who haven't followed these threads before that my cantis were set up
properly, with great pads - I could do one-finger nose wheelies and would regularly lift the rear
wheel when descending. I can't do that now (the margin between "lift" and "launch" being far too
narrow to exploit).

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

In article <[email hidden]>, Doug Taylor

Quoted message said:

Quoted message said:

I see, you haven't tried this but next time you are descending a mountain road, entering a sharp
turn, try using just the rear brake instead of the front one, in the last moment. I think you'll
see the light... maybe.

There seems to be some apples vs. oranges misunderstanding in this thread, AFAIC. Descending paved
roads on a road bike and negotiating steep technical dirt/rock/root trails on a mountain bike are
two different animals. I use different brakes and different braking technique depending on what
I'm riding where.

On the road, I use a front rim brake for 95% of my stopping, just as
Mr. Brown suggests. sheldonbrown.combrakturn.htmlOpen ↗ I rarely need anything else.

Off-road, I've moved from cantis circa 1990, to V-s circa 1995, to discs front and rear circa
2001. Cantis did not have stopping power needed for really steep terrain and technical descending.
V-s had superior stopping power but less modulation. Discs have both better than the sum of the
other two, and anybody who rides off road more than casually (except for hard core racers, so far
at least) won't settle for less.

I think I finally figured this one out. Because of the nature of disc brakes, you can run them with
much tighter pad clearance than you can run a rim brake. Less pad clearance equals less travel
necessary at the brake, which means you get more mechanical advantage or less lever travel,
designer chooses how much of each to give you. The result is powerful one-finger brakes.
Considering that my arms pumped up from applying the brakes on yesterday's ride (see below), this
seems like a good idea now.

Quoted message said:

Bumpy surfaces. On rough surfaces, your wheels may actually bounce up into the air. If there is a
chance of this, don't use the front brake. If you apply the front brake while the wheel is
airborne, it will stop, and coming down on a stopped front wheel is a Very Bad Thing."

Add in steep hills and drop offs (anybody who has endo'd grabbing a load off front brake dropping
onto a ledge knows this) and you have described off-road riding.

You're not descending steep enough hills, then. I did a 30-minute XC race yesterday which could
charitably be described as "technical". Which is a way of saying it consisted of a brutal,
hard-to-negotiate climb followed by harrowingly steep descents with plenty of drops, turns, and
rough terrain.

My experience was that the terrain was steep enough that the rear brake was nearly useless, simply
because I needed more stopping power on the descents than it could provide. Yes, I spent a lot of
time on the descents on the razor edge of endoing (and did go over once), but using my rear brake
any more would have been futile, since the rear wheel had little weight on it much of the time.

Should have dropped my seat,

--
Ryan Cousineau, [email hidden] sfu.ca~rcousineOpen ↗ President, Fabrizio Mazzoleni Fan Club

Ryan Cousineau said:

Quoted message said:

Add in steep hills and drop offs (anybody who has endo'd grabbing a load off front brake dropping
onto a ledge knows this) and you have described off-road riding.

You're not descending steep enough hills, then. I did a 30-minute XC race yesterday which could
charitably be described as "technical". Which is a way of saying it consisted of a brutal,
hard-to-negotiate climb followed by harrowingly steep descents with plenty of drops, turns, and
rough terrain.

My experience was that the terrain was steep enough that the rear brake was nearly useless, simply
because I needed more stopping power on the descents than it could provide. Yes, I spent a lot of
time on the descents on the razor edge of endoing (and did go over once), but using my rear brake
any more would have been futile, since the rear wheel had little weight on it much of the time.

You must be a real stud muffin. Here's a test for you: remove your rear brake, enter a race, then
post your results.

I had the unfortunate experience of breaking my rear brake lever in a race which involved a lot of
technical descents and steep drops. I didn't last a lap, but rather learned that there's a reason
that mtn. bikes have rear brakes (which I rarely ever use on the road).

But, then, I'm not an animal like you.

--dt

Anthony Anagnostou said:

Quoted message said:

tinyurl.coma8zsOpen ↗

Quoted message said:

Quoted message said:

That is an example of modulation.

Quoted message said:

I've been following rbt for about a year now, and this image is firmly burned into my long term
memory. i could swear ive seen it used to demonstrate the capabilities of smooth tread, lean
angles, braking in turns, impressive cornering ability, and now 'modulation' again.

It was an opportunity to demonstrate "Tinyurl"

Jobst Brandt [email hidden] Palo Alto CA

Jim Edgar <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Spider at [email hidden] wrote on 4/23/03 8:58 AM:>

Quoted message said:

No. Modulation on the trail is essential to prevent washout. My current bike went from
center-pull cantis to v-brakes front and rear to mechanical disk front, v-brake rear. I was
never able to do 1-fingered "stoppies" with my center-pulls. Even with the v-brakes, this was a
three-finger job.

In this context, it seems you are speaking about lever force, which is not the same as modulation.
What you are saying is that it's easier to apply maximal braking force. That's not the same as
modulation.

You are correct - I worded it poorly.

When you do not have to exert as much lever force to get maximal braking, fine control over the
amount of force is simpler. I can very easily control the amount of lever force I generate with one
finger. I can use much of the lever's travel by adjusting both the leverage adjustment at the lever,
and the cable "slack" AND the pad distance to the rotor. Just to clarify, the pads are usually set
as close to the rotor as possible, but without rubbing. Any lever movement needed to take up the
space between the pads and the rotor is wasted travel, unless one expects to have unintended lever
actuation.

By using one finger, I can very carefully and precisely modulate braking force each and every
application, and I never have a problem with tired hands (as I once did with cantis).

Quoted message said:

Quoted message said:

Quoted message said:

<jobst's> That would be braking force. Yes, road bicycles don't skid front wheels because they
have better traction on pavement than on a dirt road or trail, regardless of tread pattern.

This is where modulation is exceedingly important.

Huh?

On the portions of the trail where the front wheel can wash out, I need to be able to modulate the
brakes carefully. I was speaking to the conditions.

I never found that cantis modulated well. It was "not enough, not enough, not enough - too much!"
quite often. The v-brakes were better. But they can be like a switch, too, if you grab a handful. I
don't use but one finger any more. And I can feather the brakes now better than I ever could with
either cantis or Vs. I know there is more to this than just brake type, but the results speak for
themselves. Brake boss flex? Rim flex? Brake arm flex? Rim/pad glazing? Cable elasticity? I dunno.

Now, if someone could prove it wrong with math, I'll be willing to say "Yup, engineering says I'm
wrong." And I'll still use disks, because they just plain work for my application.

Spider

Mark Hickey <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Jonathan Bond said:

Doug Taylor said:

"Paul Southworth" <[email hidden]> wrote in message
"]news:[email hidden]...

> That's what I miss
>
>>most about my old cantis - I could get right to - but not beyond - the "edge" with ease. With
>>my current linar pull brake, I have to stay away from that "edge" (it bites chunks out of me
>>now!).
>
>OK, so why are you still using v-brakes? It's not like cantilevers are hard to find!

But compatible (new) frames are.

Not when you build them yourself, right Mark?

True (and the reason I'm still running canti brakes on the back - a great idea for anyone since
rear V-brakes tend to be on/off brakes where I ride).

The problem is that it's nearly impossible to find a suspension fork that's set up for canti
brakes. My last "upgrade" forced me into a V-brake mode and I've missed my cantis ever since.

I should point out for those who haven't followed these threads before that my cantis were set up
properly, with great pads - I could do one-finger nose wheelies and would regularly lift the rear
wheel when descending. I can't do that now (the margin between "lift" and "launch" being far too
narrow to exploit).

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

Indeed - set-up probably is the major factor. The disk brakes I have now are so easy to set up that
it really is a no-brainer.

Maybe the real difference between the types is ease of set-up?

Spider