V-brakes

Robin Norton said:

Are V-brakes inherently more efficient than cantilevers?

Yes.

Quoted message said:

My bike mechanic says properly adjusted cantilevers are just as good. (I'm thinking of converting
my Dawes Galaxy by putting on straight handlebars and V-brakes as I find conventional levers
tiring to use on long descents such as Alpine passes. Bob N

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

Quoted message said:

Are V-brakes inherently more efficient than cantilevers? My bike mechanic says properly adjusted
cantilevers are just as good. (I'm thinking of converting my Dawes Galaxy by putting on straight
handlebars and V-brakes

as

Quoted message said:

I find conventional levers tiring to use on long descents such as Alpine passes.

Some say not and cantis can indeed be tweaked to improve effeciency, but, vees ustilise direct pull
from the cables to the arms rather than pulling a cable up to pull the arms in which immediately
makes me think they are more effecient.

Not only that but IME vees are far easier to set up and have working at max effeciency straight off.
No contest for me and I have bikes with both types.

Pete

Robin Norton said:

I'm thinking of converting my Dawes Galaxy by putting on straight handlebars and V-brakes as I find
conventional levers tiring to use on long descents such as Alpine passes.

You could try vees with drop bars - the braking effort may be sufficiently reduced to retain the
comfort of drops.

Or maybe it's Magura time. Not sure how they are. Me, I comfort brake, and I find that the "praying
hamster" bars on my 'bent let me do that in perfect comfort.

Guy
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My old mountain bike had some old Deore cantis which stuck our much more than modern ones. Imagine
where the straddle cable hooks onto the brake, the distance apart was far wider than it is now. I
reckon that they were as effective as V brakes. They were capable of locking the wheels, once the
tyre starts skidding the brakes are useless.

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

Quoted message said:

Are V-brakes inherently more efficient than cantilevers? My bike mechanic says properly adjusted
cantilevers are just as good. (I'm thinking of converting my Dawes Galaxy by putting on straight
handlebars and V-brakes

as

Quoted message said:

I find conventional levers tiring to use on long descents such as Alpine passes. Bob N

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

Quoted message said:

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

Quoted message said:

Quoted message said:

Are V-brakes inherently more efficient than cantilevers?

As far as I'm concerned yes or IMHO.

Quoted message said:

Quoted message said:

My bike mechanic says properly adjusted cantilevers are just as good.

I've heard this said many a time, but cannot agree..err IMHO.

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Mark
____________________________
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"Just zis Guy, you know?" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Robin Norton said:

I'm thinking of converting my Dawes Galaxy by putting on straight handlebars and V-brakes

as

Quoted message said:

Quoted message said:

I find conventional levers tiring to use on long descents such as Alpine passes.

You could try vees with drop bars - the braking effort may be sufficiently reduced to retain the
comfort of drops.

The comfort of bottoming out your brake lever and still not stopping, you mean? Yes, if you're
prepared to keep it adjusted within 0.000x mm you may get away with it, but the cable pull is
just wrong.

Quoted message said:

Or maybe it's Magura time. Not sure how they are.

Rather great. Well, they're good enough for our tandems. Some people don't like the feel though
(much less springyness - once the pad hits the rim, the lever doesn't move nearly so much as with a
cable system - you use pressure, not movement. very citroen, actually...)

cheers, clive

Just zis Guy, you know? <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Robin Norton said:

I'm thinking of converting my Dawes Galaxy by putting on straight handlebars and V-brakes

as

Quoted message said:

Quoted message said:

I find conventional levers tiring to use on long descents such as Alpine passes.

You could try vees with drop bars - the braking effort may be sufficiently reduced to retain the
comfort of drops.

Or maybe it's Magura time. Not sure how they are. Me, I comfort brake, and I find that the
"praying hamster" bars on my 'bent let me do that in perfect comfort.

Guy

I ran Magura hydraulics on my 'Dale SuperVee. Personally I don't think they are any better than
properly set up V's.

They are OK though...if somewhat expensive if my memory serves me right. My bike came with them!

--
Mark
____________________________
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"]news:[email hidden]...

Quoted message said:

Robin Norton said:

Are V-brakes inherently more efficient than cantilevers?

Yes.

No they're not.

You get a greater force pressing the pad onto the rim at the expense of greater hand movement when
pulling the lever.

There is no free lunch.

Tim.

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On Mon, 19 May 2003 20:34:53 +0100, "Clive George"

Quoted message said:

Quoted message said:

You could try vees with drop bars - the braking effort may be sufficiently reduced to retain the
comfort of drops.

Quoted message said:

The comfort of bottoming out your brake lever and still not stopping, you mean? Yes, if you're
prepared to keep it adjusted within 0.000x mm you may get away with it, but the cable pull is
just wrong.

I've only ridden one bike with drops and V-brakes, and they are perfectly effective. The bike is a
tandem, owned and stoked by my mate Bob. This is the limit of my experience.

Guy
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Tim Cain said:

"]news:[email hidden]...

Quoted message said:

Robin Norton said:

Are V-brakes inherently more efficient than cantilevers?

Yes.

No they're not.

You get a greater force pressing the pad onto the rim at the expense of greater hand movement when
pulling the lever.

You get the same force at the rim for less hand/finger pressure at the lever. The hand/finger
doesn't move (In my experience, replacing canti's with vee's, both brakes and levers) any further
than cantilever brakes, that's taken up with the leverage and positioning of the pivot points,
provided you use vee brake levers ..

Quoted message said:

There is no free lunch.

Who mentioned lunch ?

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"]news:[email hidden]...

Quoted message said:

Tim Cain wrote:

Quoted message said:

Quoted message said:

"]news:[email hidden]...

Quoted message said:

Robin Norton wrote:
> Are V-brakes inherently more efficient than cantilevers?

Yes.

No they're not.

You get a greater force pressing the pad onto the rim at the expense of greater hand movement
when pulling the lever.

You get the same force at the rim for less hand/finger pressure at the lever. The hand/finger
doesn't move (In my experience, replacing canti's with vee's, both brakes and levers) any further
than cantilever brakes, that's taken up with the leverage and positioning of the pivot points,
provided you use vee brake levers ..

V's have a higher mechanical advantage for sure: Greater pressure at rim for a given force at the
brake lever (wrt cantilevers). But for a given displacement of the pad wrt the rim, the lever must
move in proportion to the mechanical advantage of the system.

Quoted message said:

Quoted message said:

There is no free lunch.

Who mentioned lunch ?

You say that V-brakes are more efficient than cantilevers.

Efficiency = work input / work output.

(work = force * distance moved)

The efficiency of V-brakes and cantilevers is practically identical ( = work input - a bit of loss
due to cable friction, viscosity in the brake arm bearings, and stretching it a bit, hysteresis in
the brake arm return springs). Very close to unity for both, I'd guess.

Now, if V-brakes are more efficient than cantilevers, where is the extra work coming from?

Who is supplying the free (working) lunch?

Tim.

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"Tim Cain" <tim_no1@you_know_what_to_cut_timcain.co.uk> wrote in message
"]news:[email hidden]...

Quoted message said:

Quoted message said:

"]news:[email hidden]...

Quoted message said:

Tim Cain wrote:

Quoted message said:

Quoted message said:

Quoted message said:

"]news:[email hidden]...
> Robin Norton wrote:
>> Are V-brakes inherently more efficient than cantilevers?
>
> Yes.
>

No they're not.

You get a greater force pressing the pad onto the rim at the expense of greater hand movement
when pulling the lever.

You get the same force at the rim for less hand/finger pressure at the lever. The hand/finger
doesn't move (In my experience, replacing canti's with vee's, both brakes and levers) any
further than cantilever brakes, that's taken up with the leverage and positioning of the pivot
points, provided you use vee brake levers ..

V's have a higher mechanical advantage for sure: Greater pressure at rim for a given force at the
brake lever (wrt cantilevers). But for a given displacement of the pad wrt the rim, the lever must
move in proportion to the mechanical advantage of the system.

Quoted message said:

Quoted message said:

There is no free lunch.

Who mentioned lunch ?

You say that V-brakes are more efficient than cantilevers.

Efficiency = work input / work output.

Ack! should be: "Efficiency = work output / work input", of course.

Quoted message said:

(work = force * distance moved)

The efficiency of V-brakes and cantilevers is practically identical ( = work input - a bit of loss
due to cable friction, viscosity in the brake arm bearings, and stretching it a bit, hysteresis in
the brake arm return springs). Very close to unity for both, I'd guess.

Now, if V-brakes are more efficient than cantilevers, where is the extra work coming from?

Who is supplying the free (working) lunch?

Tim.

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Robin Norton said:

Are V-brakes inherently more efficient than cantilevers?

Who cares ? V's are less sensitive to pad wear, have no obvious bad habits, and that's enough to
convince me.

Cantis can work fine if you fiddle, but it's a pain to do, and how many of us really do it often
enough to keep them running that well ? (especially on a commuter).

Personally I have the best of both worlds - I run a V on the front and a canti at the back.

I built an old bike up for a friend at the w/e. The brakes are cantis from my spares box (I've
finally ditched the anodised purple brake levers!) and they're cantis simply because putting a V on
the front would have meant buying some new levers.

Sadly the front canti is an Onza HO - brand new, in box. It cost some insane amount new, but I
picked it up in a sale for a fiver or so. The "Chill Pill" straddle has always been a neat looking,
but poorly functioning piece of [censored] (the screw doesn't grip and the cable routing tries to stick it
into the tyre tread), but I've never before seen such a misbegotten bit of over-hyped CNC as the
cantis. These things are just nasty - I broke the dust cover first time I pulled on the lever.
There's no clearance around the pull-off spring, so it bursts the plastic tube when they pivot.

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

Quoted message said:

Are V-brakes inherently more efficient than cantilevers?

Unless someone has some good force diagrams to convince me otherwise: YES.

Quoted message said:

My bike mechanic says properly adjusted cantilevers are just as good.

Even badly adjusted V-brakes are pretty damn efficient.

Quoted message said:

(I'm thinking of converting my Dawes Galaxy by putting on straight handlebars and V-brakes

as

Quoted message said:

I find conventional levers tiring to use on long descents such as Alpine passes.

Poor old Galaxy. I have a (cough) flat barred 26" wheel V-braked (cough) tourer.

W K said:

Quoted message said:

Are V-brakes inherently more efficient than cantilevers?

Unless someone has some good force diagrams to convince me otherwise: YES.

I think what you mean is are they more powerful? and the answer to that is yes. Simply more cable
pull equals more mechanical advantage at the brake end, especially with those long arms.

--
-Alex

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----------------------------------

Just zis Guy said:

I've only ridden one bike with drops and V-brakes, and they are perfectly effective. The bike is a
tandem, owned and stoked by my mate Bob. This is the limit of my experience.

It probably had proper levers. There is only one drop bar lever for V brakes that I know of and
thats the Dia Compe 287V:

<http://www.sjscycles.com/store/item70.htm>

--
-Alex

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"Tim Cain" <tim_no1@you_know_what_to_cut_timcain.co.uk> wrote in message
"]news:[email hidden]...

Quoted message said:

Quoted message said:

"]news:[email hidden]...

Quoted message said:

Tim Cain wrote:

Quoted message said:

Quoted message said:

Quoted message said:

"]news:[email hidden]...
> Robin Norton wrote:
>> Are V-brakes inherently more efficient than cantilevers?
>
> Yes.
>

No they're not.

You get a greater force pressing the pad onto the rim at the expense of greater hand movement
when pulling the lever.

You get the same force at the rim for less hand/finger pressure at the lever. The hand/finger
doesn't move (In my experience, replacing canti's with vee's, both brakes and levers) any
further than cantilever brakes, that's taken up with the leverage and positioning of the pivot
points, provided you use vee brake levers ..

V's have a higher mechanical advantage for sure: Greater pressure at rim for a given force at the
brake lever (wrt cantilevers). But for a given displacement of the pad wrt the rim, the lever must
move in proportion to the mechanical advantage of the system.

Quoted message said:

Quoted message said:

There is no free lunch.

Who mentioned lunch ?

You say that V-brakes are more efficient than cantilevers.

Efficiency = work input / work output.

(work = force * distance moved)

The efficiency of V-brakes and cantilevers is practically identical ( = work input - a bit of loss
due to cable friction, viscosity in the brake arm bearings, and stretching it a bit, hysteresis in
the brake arm return springs). Very close to unity for both, I'd guess.

I'd guess that the upward force on the vertical cable is in fact wastefully converted into two
forces at an angle to the first. Then - unless perfectly aligned (and even then doubtful) - the two
cables to the top of the cable might not be pulling perpendicular to the pivot/attatchment.

Quoted message said:

Now, if V-brakes are more efficient than cantilevers, where is the extra work coming from?

Wrong way round.

Quoted message said:

Who is supplying the free (working) lunch?

Cantilevers are less efficient and V brakes aren't magical.

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

Quoted message said:

"Tim Cain" <tim_no1@you_know_what_to_cut_timcain.co.uk> wrote in message
"]news:[email hidden]...

Quoted message said:

Quoted message said:

Quoted message said:

"]news:[email hidden]...

Quoted message said:

Tim Cain wrote:

Quoted message said:

Quoted message said:

Quoted message said:

> "]news:[email hidden]...
>> Robin Norton wrote:
>>> Are V-brakes inherently more efficient than cantilevers?
>>
>> Yes.
>>
>
> No they're not.
>
> You get a greater force pressing the pad onto the rim at the expense of greater hand
> movement when pulling the lever.

You get the same force at the rim for less hand/finger pressure at the lever. The hand/finger
doesn't move (In my experience, replacing canti's with vee's, both brakes and levers) any
further than

cantilever

Quoted message said:

Quoted message said:

Quoted message said:

brakes, that's taken up with the leverage and positioning of the pivot points, provided you
use vee brake levers ..

V's have a higher mechanical advantage for sure: Greater pressure at rim for a given force at
the brake lever (wrt cantilevers). But for a given displacement of the pad wrt the rim, the
lever must move in proportion to the mechanical advantage of the system.

Quoted message said:

> There is no free lunch.

Who mentioned lunch ?

You say that V-brakes are more efficient than cantilevers.

Efficiency = work input / work output.

(work = force * distance moved)

The efficiency of V-brakes and cantilevers is practically identical ( = work input - a bit of
loss due to cable friction, viscosity in the brake arm bearings, and stretching it a bit,
hysteresis in the brake arm return springs). Very close to unity for both, I'd guess.

I'd guess that the upward force on the vertical cable is in fact

wastefully

Quoted message said:

converted into two forces at an angle to the first.

Where's the waste? Is the work being converted into heat, sound, light, or what?

Answer: None of the above. They (V's & cantilevers) are equally efficient.

Quoted message said:

Then - unless perfectly aligned (and even then doubtful) - the two cables

to

Quoted message said:

the top of the cable might not be pulling perpendicular to the pivot/attatchment.

Quoted message said:

Now, if V-brakes are more efficient than cantilevers, where is the extra work coming from?

Wrong way round.

You really ought to expand this section of your argument.

Quoted message said:

Quoted message said:

Who is supplying the free (working) lunch?

Cantilevers are less efficient and V brakes aren't magical.

In what way are cantilevers less efficient? How are you measuring or defining efficiency?

Tim.

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Quoted message said:

Quoted message said:

I'd guess that the upward force on the vertical cable is in fact

wastefully

Quoted message said:

converted into two forces at an angle to the first.

Where's the waste? Is the work being converted into heat, sound, light, or what?

Increased tension in the cable compared to identical force on the side of the rim with V-brakes.
Once the pads are pushed onto the rim a lot of the force from a cantilever is simply pulling the
entire brake construction upwards - of course it doesn't move upwards since the bosses are stronger
than you are, so you end up stretching the cable more than you do with a V-brake where there is
almost zero effort being lost pulling upwards.

Pulling something in a direction other than the one you actually want it to go is always going to be
less efficient then pulling only in the direction you want it to go.

Mads Hilberg