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V-brakes

 
 
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  #1  
Old 05-19.-2003
Robin Norton
 
Posts: n/a
Default V-brakes

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 I find conventional levers tiring to use on long descents such as Alpine
passes. Bob N
  #2  
Old 05-19.-2003
Anonymous
 
Posts: n/a
Default Re: V-brakes

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

Yes.

> 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

--

Completed 1666 Seti work units in 12694 hours http://setiathome.ssl.berkeley.edu/
  #3  
Old 05-19.-2003
Peter B
 
Posts: n/a
Default Re: V-brakes

"Robin Norton" <nortonrj@esatclear.ie> wrote in message news:bab5ds$r72$1@dorito.esatclear.ie...
> 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
> 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
  #4  
Old 05-19.-2003
Just Zis Guy
 
Posts: n/a
Default Re: V-brakes

On Mon, 19 May 2003 18:45:41 +0100, "Robin Norton" <nortonrj@esatclear.ie> wrote:

>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
===
** WARNING ** This posting may contain traces of irony. http://www.chapmancentral.com (BT ADSL and
dynamic DNS permitting)
NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer
work. Apologies.
  #5  
Old 05-19.-2003
M Series
 
Posts: n/a
Default Re: V-brakes

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" <nortonrj@esatclear.ie> wrote in message news:bab5ds$r72$1@dorito.esatclear.ie...
> 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
> I find conventional levers tiring to use on long descents such as Alpine passes. Bob N
  #6  
Old 05-19.-2003
Msa
 
Posts: n/a
Default Re: V-brakes

Peter B <peter28@btinternet.com> wrote in message news:bab70b$rlj$1@titan.btinternet.com...
>
> "Robin Norton" <nortonrj@esatclear.ie> wrote in message news:bab5ds$r72$1@dorito.esatclear.ie...

> > Are V-brakes inherently more efficient than cantilevers?

As far as I'm concerned yes or IMHO.

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

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

--
Mark
____________________________
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  #7  
Old 05-19.-2003
Anonymous
 
Posts: n/a
Default Re: V-brakes

"Just zis Guy, you know?" <guy.chapman@spamcop.net> wrote in message
news:nobicv0i6pom99p7cej0idoi6d7lq5bs0o@4ax.com...
> On Mon, 19 May 2003 18:45:41 +0100, "Robin Norton" <nortonrj@esatclear.ie> wrote:
>
> >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.

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.

> 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
  #8  
Old 05-19.-2003
Msa
 
Posts: n/a
Default Re: V-brakes

Just zis Guy, you know? <guy.chapman@spamcop.net> wrote in message
news:nobicv0i6pom99p7cej0idoi6d7lq5bs0o@4ax.com...
> On Mon, 19 May 2003 18:45:41 +0100, "Robin Norton" <nortonrj@esatclear.ie> wrote:
>
> >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

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
____________________________
Practice does not make perfect... Perfect practice makes perfect

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  #9  
Old 05-19.-2003
Tim Cain
 
Posts: n/a
Default Re: V-brakes

news:bab64j$r195l$1@ID-137265.news.dfncis.de...
> 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.

There is no free lunch.

Tim.

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  #10  
Old 05-19.-2003
Just Zis Guy
 
Posts: n/a
Default Re: V-brakes

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

>> 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.

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
===
** WARNING ** This posting may contain traces of irony. http://www.chapmancentral.com (BT ADSL and
dynamic DNS permitting)
NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer
work. Apologies.
  #11  
Old 05-19.-2003
Anonymous
 
Posts: n/a
Default Re: V-brakes

Tim Cain wrote:

> news:bab64j$r195l$1@ID-137265.news.dfncis.de...
>> 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 ..

> There is no free lunch.

Who mentioned lunch ?

--

Completed 1666 Seti work units in 12694 hours http://setiathome.ssl.berkeley.edu/
  #12  
Old 05-19.-2003
Tim Cain
 
Posts: n/a
Default Re: V-brakes

news:babhha$rdb5a$1@ID-137265.news.dfncis.de...
> Tim Cain wrote:

> > news:bab64j$r195l$1@ID-137265.news.dfncis.de...
> >> 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.

> > 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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  #13  
Old 05-19.-2003
Tim Cain
 
Posts: n/a
Default Re: V-brakes

"Tim Cain" <tim_no1@you_know_what_to_cut_timcain.co.uk> wrote in message
news:3ec94dcd$0$11381$cc9e4d1f@news.dial.pipex.com...
>

> news:babhha$rdb5a$1@ID-137265.news.dfncis.de...
> > Tim Cain wrote:

> > > news:bab64j$r195l$1@ID-137265.news.dfncis.de...
> > >> 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.
>
> > > 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.

>
> (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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> Version: 6.0.483 / Virus Database: 279 - Release Date: 19/05/03
>
>

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  #14  
Old 05-19.-2003
Andy Dingley
 
Posts: n/a
Default Re: V-brakes

On Mon, 19 May 2003 18:45:41 +0100, "Robin Norton" <nortonrj@esatclear.ie> wrote:

>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 crap (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.
  #15  
Old 05-19.-2003
W K
 
Posts: n/a
Default Re: V-brakes

"Robin Norton" <nortonrj@esatclear.ie> wrote in message news:bab5ds$r72$1@dorito.esatclear.ie...

> Are V-brakes inherently more efficient than cantilevers?

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

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

Even badly adjusted V-brakes are pretty damn efficient.

> (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.

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

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