Why the demise of the Centre Pull brake?

[carpenter]

I grew up admiring them and dismantling/cleaning/mucking up at times (all part of the learning process as a kid - didn't have computers in the good old days ).
I still think they just look right, and logical on older bikes.

I guess, as others have said that it was a combination of fashion, ease of manufacturing, less materials?

By the way, they work well for me, with Koolstop Continentals - not sure if that is because the Weinmann pads that I have are so old and hard now?
I find them easier to centre/set up than side pulls, so all in all it's a good job that they made them so well that they still look good and work today (and quite possibly will continue to do so for the next sixty years).

I also like Shimano 105 brakes, so not particularly partisan in the matter (I keep on looking at Campagnolo "skeleton" brakes on eBay and would like to try them, purely on the basis of he look - how shallow can I get).

 

[Grant Fondo]

Mine still stop fairly well, but thete is a downside....

 

[carpenter]

Where's the brake?

 

[GuyBoden]

For me, the brilliance of the twin-pivot sidepull is the interconnection between the two lever arms. This interconnection obliges both arms to act in unison.

Just to be overly pedantic, both arms on the dual pivot single caliper brakes do not pull in exact unison, but they are near enough that you don't really notice in practice.
See below for explanation:

Interestingly, with dual pivot single caliper brakes one side is pulled before the other. It's an inherent part of the design. The centre pull brake does not suffer from this design.

Mechanically they can't be exactly synchronised, because one pivot is central and the other pivot at one side. The design is a combination of a single side pull pivot and a centre pull pivot. It's a compromise that works well in practice.

 

[rogerzilla]

The synchronisation is convenient for centring but is otherwise bad. A "floating" brake like a normal side-pull/cantilevers/V-brake/most centrepulls tracks the rim better and doesn't drag badly if the rear one rubs due to frame flex on steep hills. You used to see the pros riding with the rear QR open on mountain climbs (still do if they use rim brakes). I have to do this myself on the noodlier bikes.

 

[midlife]

Bernard Thevenet made gold Mafac centre pulls look cool in 1975

 

[GuyBoden]

The only time I've dealt with centerpulls lately, I found them to be a nightmare to set up, compared with DP sidepulls.
Braze-on CP brakes look very like the U-brakes that were around on MTBs in the 90s.
That Pug looks nice though. Lovely colour

This video describes the basic setup:

View: https://www.youtube.com/watch?v=iJeYSKUI-6A

 

[raleighnut]

For me, the brilliance of the twin-pivot sidepull is the interconnection between the two lever arms. This interconnection obliges both arms to act in unison. Single-pivot sidepulls often suffer from one pad hitting the rim first, which then provides the resistance to pull the other pad on to the other side of the rim. On release, the brake blocks of single-pivot sidepulls are seldom equidistant from the rim.

Centrepulls are largely immune to this problem but at the expense of some extra weight including the hangers and straddle cable. Even so, centrepull designs using brazed-on fittings may well be a bit lighter overall than the alternatives.

Aesthetically, I find centrepulls make a bike look cluttered; especially the bigger-is-better versions such as the old Mafac Tiger. Twin-pivot sidepulls can be made neat and compact and, of course, have none of the hangers and additional cable stops of centrepulls.

I have no personal experience of disc brakes but I find Chris Boardman's comments sound sensible. Given the extra hassle for wheel changing, I would not be surprised to see discs gradually retreating to MTBs as time goes by. They must be more aerodynamic but an extra 30" taken in a wheel change can be the difference between getting back in the bunch and ending up in the autobus.

Twin pivot sidepulls are nothing new, my 1967 Carlton came fitted with these,

Weinmann 'Dynamic'

 

[Once a Wheeler]

Twin pivot sidepulls are nothing new, my 1967 Carlton came fitted with these, Weinmann 'Dynamic'

The first ones I am aware of are the GB Synchron brakes which were on sale in 1963. The Mk II version of around 1965 looked almost identical to the Weinmann Dynamics in your photograph. In the Mk I version, the outer arm projected above the pivot of the inner arm, making the block movement more restricted. A quick-release device was incorporated into the levers to allow rapid wheel removal.

GB, by the way, was the trademark of Gerry Burgess who produced a range of cycle components from the 1950s through to about the 1970s. Much of their output was lower-priced versions of goods from the Continental suppliers. It would be nice to know if the Synchron concept was a GB patent or registered design. I am not aware of seeing it on any pre-1963 bikes.

Those Weinmann Dynamics look to be in really good shape.

Stop press:
The GB Synchron Mk I. More details here: http://www.classicrendezvous.com/British_isles/GB/GB_Altenburger.htm