Who invented dual-pivot brakes?

Discussion in 'Cycling Equipment' started by Jeff, May 31, 2003.

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  1. Jeff

    Jeff Guest

    An intermittent cyclist, I rode throughout 70s on centerpulls. They worked well enough. Rode through
    the 80s and 90s on sidepulls. They worked a bit better.

    Today I installed my first dual-pivot side-pull brakes. The easiest adjusting brakes I know, by far.

    Curious - who invented this marvel?
     
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  2. Jeff wrote:

    > An intermittent cyclist, I rode throughout 70s on centerpulls. They worked well enough. Rode
    > through the 80s and 90s on sidepulls. They worked a bit better.
    >
    > Today I installed my first dual-pivot side-pull brakes. The easiest adjusting brakes I
    > know, by far.
    >
    > Curious - who invented this marvel?

    In one sense, they go back to the Dawn of Time, because cantilevers and centerpulls are technically
    "dual pivot."

    However, if youre speaing of modern dual pivot sidepulls, the earliest ones I know of were made by
    Altenberger in the late '60s.

    They were generally considered slightly inferior to the popular centerpull calipers of the day from
    Mafac, Weinmann, Universal and GB.

    The superiority of modern brakes has much more to do with improved levers, cables and shoes than it
    does with caliper design.

    Sheldon "Used To Ride With An Altenberger On The Back" Brown
    +---------------------------------------+
    | Whatever became of eternal truth? |
    +---------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
    617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  3. Shimano, I believe.

    May you have the wind at your back. And a really low gear for the hills! Chris

    Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner
     
  4. Jeff

    Jeff Guest

    "Sheldon Brown" <[email protected]> wrote
    > The superiority of modern brakes has much more to do with improved levers, cables and shoes than
    > it does with caliper design.

    My [limited] experience is I could never fine-tune single-pivot side-pull brakes.

    Seems like the dual-pivots are much, much easier.
     
  5. Jobst Brandt

    Jobst Brandt Guest

    Sheldon Brown writes:

    >> An intermittent cyclist, I rode throughout 70s on centerpulls. They worked well enough. Rode
    >> through the 80s and 90s on sidepulls. They worked a bit better.

    >> Today I installed my first dual-pivot side-pull brakes. The easiest adjusting brakes I know,
    >> by far.

    >> Curious - who invented this marvel?

    > In one sense, they go back to the Dawn of Time, because cantilevers and centerpulls are
    > technically "dual pivot."

    I think you should be more exacting in the definition. THE dual pivot, as we know it today, was
    introduced for its forced centering that can only be done with two pivot points. It is this self
    centering that makes possible the higher mechanical advantage... the feature that most people like
    about them. Centerpull are self contained cantilevers and both suffer from large cosine error, the
    pivot points being on a nearly 45 degree axis from pad contact... dogs!

    http://draco.acs.uci.edu/rbfaq/FAQ/8f.15.html

    > However, if you're speaking of modern dual pivot sidepulls, the earliest ones I know of were made
    > by Altenburger in the late '60s.

    Yes, but they did not take advantage of the lower pad clearance possible with centered brakes.
    They didn't see the need and were to timid to diverge from the standard 4:1 mechanical advantage
    of the day.

    > They were generally considered slightly inferior to the popular centerpull calipers of the day
    > from Mafac, Weinmann, Universal and GB.

    That was a bunch of marketing. I chucked the centerpulls immediately and switched to Universal side
    pulls before Campagnolo brakes were generally available. Centerpull brakes were duds right from the
    start but were touted to have greater stopping power because they had twice the force... a complete
    lie. They had 4:1 like all brakes of the day.

    > The superiority of modern brakes has much more to do with improved levers, cables and shoes than
    > it does with caliper design.

    It has only one feature and that is a higher mechanical advantage. The short arm on the offset pivot
    has significant cosine error (foreshortening caused by angular motion. A conventional side pull
    brake operating at less than 5 degrees has less than 4% vertical motion of the pad from new to worn
    to the metal. No other mechanical lever brake can be operated for the life of the pad without
    adjustment. The pad position on my old Campagnolo brakes never need adjustment. Only cable slack
    from pad wear need be taken up and it can do that as well.

    Jobst Brandt [email protected] Palo Alto CA
     
  6. Dave Mayer

    Dave Mayer Guest

    A pal of mine has some spare Altenberger dual pivots . They are 60's vintage, and pretty good shape.
    They're mine for free if I want to drop them on a bike. Is there any point for me to do this?

    "Chris Zacho "The Wheelman"" <[email protected]> wrote in message
    news:[email protected]...
    > Shimano, I believe.
    >
    > May you have the wind at your back. And a really low gear for the hills! Chris
    >
    > Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner
     
  7. chris-<< Shimano, I believe.

    errrrr, thank you for playing....

    like most things 'bike', shimano is wonderful at improving the design, but original designs are not
    something 'shimano'....

    Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
  8. Neacalban1

    Neacalban1 Guest

    >> An intermittent cyclist, I rode throughout 70s on centerpulls. They worked well enough. Rode
    >> through the 80s and 90s on sidepulls. They worked a bit better.
    >>

    not very demanding, were you? todays dual-pivot brakes are far and away easier to adjust,maintain,
    and offer much greater modulation and stopping power than what was available back then(yeah, I know,
    thats what you inferred.
    :)
    I was just reminiscing- Sears Free Spirit- with steel side-pulls with "safety levers" - amazing how
    many people didnt get killed on those. Dura-Ace brakes(mine was circa 1976)- my set was hard to
    adjust and had an incredible squeal. no matter how far I toed them, tightened them, whatever. a
    neighbor who worked for NASA(harbinger of Challenger....?) said it was pressure and not friction
    that stpped the wheels, so he sprayed silicone on the brake pads for
    me..... I went down the hill with the levers locked to the bars- no squeal,no stop. never bought
    another Shimano part. all those steel sidepulls- took forever to smack the springs just right.
     
  9. Waal

    Waal Guest

    "Qui si parla Campagnolo" <[email protected]> skrev i en meddelelse
    news:[email protected]...
    > chris-<< Shimano, I believe.
    >
    >
    > errrrr, thank you for playing....
    >
    > like most things 'bike', shimano is wonderful at improving the design, but original designs are
    > not something 'shimano'....

    maybe something like :http://www.classicrendezvous.com/British/conloy_3_brks.html

    Michael
    >
    >
    > Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
    > (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"
     
  10. Jobst Brandt wrote:

    > Centerpull are self contained cantilevers and both suffer from large cosine error, the pivot
    > points being on a nearly 45 degree axis from pad contact... dogs!
    >
    > http://draco.acs.uci.edu/rbfaq/FAQ/8f.15.html

    The popularity of centerpull calipers was in a time when most rims had angled braking surfaces, as
    opposed to the parallel braking surfaces that are now the norm.

    For such rims, the cosine "error" of centerpull calipers (or "U brakes") is actually a feature!

    I had reminisced:

    >>However, if you're speaking of modern dual pivot sidepulls, the earliest ones I know of were made
    >>by Altenburger in the late '60s.

    > Yes, but they did not take advantage of the lower pad clearance possible with centered brakes.
    > They didn't see the need and were to timid to diverge from the standard 4:1 mechanical advantage
    > of the day.

    >>They were generally considered slightly inferior to the popular centerpull calipers of the day
    >>from Mafac, Weinmann, Universal and GB.

    > That was a bunch of marketing. I chucked the centerpulls immediately and switched to Universal
    > side pulls before Campagnolo brakes were generally available. Centerpull brakes were duds right
    > from the start but were touted to have greater stopping power because they had twice the force...
    > a complete lie. They had 4:1 like all brakes of the day.

    The Universals were very nice calipers indeed. However, I believe that comparing '60s and '70s
    centerpulls with garden variety long-reach sidepulls, as fitted on "sport-touring" tenspeeds of the
    era, the centerpulls generally had a higher mechanical advantage, at least when properly set up.

    >>The superiority of modern brakes has much more to do with improved levers, cables and shoes than
    >>it does with caliper design.

    > It has only one feature and that is a higher mechanical advantage. The short arm on the offset
    > pivot has significant cosine error (foreshortening caused by angular motion. A conventional side
    > pull brake operating at less than 5 degrees has less than 4% vertical motion of the pad from new
    > to worn to the metal. No other mechanical lever brake can be operated for the life of the pad
    > without adjustment.

    That generalization has been invalidated by the move to thinner pads! It also doesn't apply to
    centerpulls used with angled rims, nor to various brake types used with rims with a tall braking
    surface, such as the (yuck!) Weinmann concave.

    > The pad position on my old Campagnolo brakes never need adjustment. Only cable slack from pad wear
    > need be taken up and it can do that as well.

    This feature is certainly of some value, but it isn't overwhelming. Not all cyclists have as strong
    hands as you do, and some of us with weak hands find old Campagnolo sidepulls highly unsatisfactory.

    Sheldon "Current Campag Brakes Are Fine" Brown +----------------------------------------+
    | The race is not always to the swift, | nor the battle to the strong | -but that's the way to bet.
    | | --Damon Runyon |
    +----------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
    617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  11. Mike S.

    Mike S. Guest

    "Qui si parla Campagnolo" <[email protected]> wrote in message
    news:[email protected]...
    > chris-<< Shimano, I believe.
    >
    >
    > errrrr, thank you for playing....
    >
    > like most things 'bike', shimano is wonderful at improving the design, but original designs are
    > not something 'shimano'....
    >
    >
    > Peter Chisholm

    Just like the "Bullseye" cranks that Shimano is bringing out this year for
    D/A and XTR...

    Mike
     
  12. Jeff

    Jeff Guest

    Lubric*ting the br*ke p*ds! The maintenance error I dare not speak out loud. I have nightmares about
    that. Glad you survived to tell the tale.

    "Neacalban1" <[email protected]> wrote
    > so he sprayed silicone on the brake pads for
    > me..... I went down the hill with the levers locked to the bars- no
    squeal,no
    > stop.
     
  13. Sheldon Brown <[email protected]> writes:

    >Jeff wrote:

    >> Today I installed my first dual-pivot side-pull brakes. The easiest adjusting brakes I know, by
    >> far. Curious - who invented this marvel?
    >
    >The superiority of modern brakes has much more to do with improved levers, cables and shoes than it
    >does with caliper design.

    I love the action of the old centerpulls. Since the centerpulls (and cantilevers) are basically
    lengthening a rhombus, they have (i think) twice the mechanical advantage, but twice the lever
    travel. that's why the old weinmann levers stuck out so far in front of the handlebars, and why
    "suicide levers" (e.g. dia compe extensions) didn't work.

    In my opinion, campy sidepulls were not an improvement over centerpulls. They were just lighter,
    thats all. Weinmann Centerpulls (and most cantilevers) can crush a tandem wheel if you reaally need
    to stop quickly. sidepulls cannot do that, never in the past, and never in the future ...

    - Don Gillies San Diego, CA
     
  14. On Sun, 01 Jun 2003 14:37:50 +0000, Neacalban1 wrote:

    > Dura-Ace brakes(mine was circa 1976)- my set was hard to adjust and had an incredible squeal. no
    > matter how far I toed them, tightened them, whatever. a neighbor who worked for NASA(harbinger of
    > Challenger....?) said it was pressure and not friction that stpped the wheels, so he sprayed
    > silicone on the brake pads for
    > me..... I went down the hill with the levers locked to the bars- no squeal,no stop. never bought
    > another Shimano part.

    I think you're blaming the wrong people for that. How an engineer could say that is beyond
    comprehension.

    --

    David L. Johnson

    __o | "What am I on? I'm on my bike, six hours a day, busting my ass. _`\(,_ | What are you on?"
    --Lance Armstrong (_)/ (_) |
     
  15. Tim McNamara

    Tim McNamara Guest

    In article <[email protected]>, [email protected] (Neacalban1) wrote:

    > todays dual-pivot brakes are far and away easier to adjust, maintain, and offer much greater
    > modulation and stopping power

    These things are mutually exclusive in a simple lever like a bicycle rim brake. You might personally
    find dual pivots to be a better compromise than, say, single pivot brakes.
     
  16. In article <[email protected]>, [email protected] says...

    >Just like the "Bullseye" cranks that Shimano is bringing out this year for
    >D/A and XTR...

    The ones with the Magic Motorcycle/CODA outside of the BB shell bearings? Hollow like the
    MM/CODA cranks? The only part they didn't copy was a lobed tapered press fit interface between
    the cranks and BB.
    ----------------
    Alex
     
  17. Jobst Brandt

    Jobst Brandt Guest

    Sheldon Brown writes:

    >> It has only one feature and that is a higher mechanical advantage. The short arm on the offset
    >> pivot has significant cosine error (foreshortening caused by angular motion. A conventional side
    >> pull brake operating at less than 5 degrees has less than 4% vertical motion of the pad from new
    >> to worn to the metal. No other mechanical lever brake can be operated for the life of the pad
    >> without adjustment.

    > That generalization has been invalidated by the move to thinner pads! It also doesn't apply to
    > centerpulls used with angled rims, nor to various brake types used with rims with a tall braking
    > surface, such as the (yuck!) Weinmann concave.

    There is no rim surface that will negate cosine error. Pad thickness only comes into play to make
    pads wear out so fast that they need to be replaced often, thereby keeping the angular change close
    to zero. That is a stupid solution and it does nothing for cantilever and V-brakes that have large
    cosine error.

    >> The pad position on my old Campagnolo brakes never need adjustment. Only cable slack from pad
    >> wear need be taken up and it can do that as well.

    > This feature is certainly of some value, but it isn't overwhelming. Not all cyclists have as
    > strong hands as you do, and some of us with weak hands find old Campagnolo sidepulls highly
    > unsatisfactory.

    It is important if you use the brakes on long descents, in the Alps in the rain, for instance. I can
    imagine this happening n the great tour races, TdF, GdI, TdS and others. Just because most Americans
    don't ride such courses, straying that far from their bicycle mechanic, doesn't justify such an
    unnecessary built in error.

    By the way, current dual-pivot brakes can lock up a front wheel if it gets knocked a couple of
    centimeters out of true, such as a 24-spoke wheel in which a spoke breaks on a descent. The Dual
    pivot brake cannot follow an untrue wheel as single pivot brakes have done on purpose for many
    years. I am not amused and fortunately have hands strong enough to raise the rear wheel on descents
    if I need to brake that hard.

    Jobst Brandt [email protected] Palo Alto CA
     
  18. Jobst Brandt

    Jobst Brandt Guest

    Donald Gillies writes:

    > I love the action of the old centerpulls. Since the centerpulls (and cantilevers) are basically
    > lengthening a rhombus, they have (i think) twice the mechanical advantage, but twice the lever
    > travel. that's why the old Weinmann levers stuck out so far in front of the handlebars, and why
    > "suicide levers" (e.g. Dia Compe extensions) didn't work.

    Not true! These brakes all had a 4:1 ratio that was entirely in the hand lever... the distance from
    the pivot to the cable and the distance from the hand lever crook from that same pivot. The calipers
    were all 1:1. Of course that is easy to measure. Measure pad clearance (this can be done by pushing
    one pad to the rim and measuring the resulting clearance on the other pad. Then measure how much
    hand lever cable moves to bring the pads into contact with the rim.

    > In my opinion, Campy sidepulls were not an improvement over centerpulls. They were just lighter,
    > thats all. Weinmann Centerpulls (and most cantilevers) can crush a tandem wheel if you really need
    > to stop quickly. sidepulls cannot do that, never in the past, and never in the future...

    Oh Bull Shit! I can see you will lose a bunch of money if you take bets on that. Besides, the
    migration of pad contact into the tire (aka cosine error) is a major hazard for people unclear on
    the concept because it causes blowouts. Cantilevers, in contrast, "pop under" the rim with wear and
    do not return, leaving the bicycle with no brake. If you find that no improvement then it is a
    matter of definition. I disagree.

    Jobst Brandt [email protected] Palo Alto CA
     
  19. Tom Ace

    Tom Ace Guest

    Sheldon Brown wrote:

    > > The pad position on my old Campagnolo brakes never need adjustment. Only cable slack from pad
    > > wear need be taken up and it can do that as well.
    >
    > This feature is certainly of some value, but it isn't overwhelming. Not all cyclists have as
    > strong hands as you do, and some of us with weak hands find old Campagnolo sidepulls highly
    > unsatisfactory.
    >
    > Sheldon "Current Campag Brakes Are Fine" Brown

    Correct me if I'm wrong, but didn't the (original) Campagnolo calipers have roughly the same
    mechanical advantage as other sidepulls of the time (e.g. Universal Super 68)? I'd thought that the
    greater effort required was due to the design of Record levers, not the calipers.

    Tom Ace
     
  20. Sheldon Brown <[email protected]> wrote in message
    news:<[email protected]>...

    > However, if youre speaing of modern dual pivot sidepulls, the earliest ones I know of were made by
    > Altenberger in the late '60s.
    >
    > They were generally considered slightly inferior to the popular centerpull calipers of the day
    > from Mafac, Weinmann, Universal and GB.

    Beat me to it! Think they were a joint venture with GB, being marketed over here as the "GB
    Synchron". The Classic Rendezvous website has a bit of info, plus an advert of the time, under its
    "British Components" section.

    David E. Belcher

    Dept. of Chemistry, University of York
     
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