Monday, October 14, 2013

Endangered Species: Single-Pivot Sidepull Brakes

Sidepull caliper brakes are the primary choice for high performance road bikes, and have been for decades, although it was not always a complete domination. Look at old race photos from the 40s, 50s and even 60s, and one can find a lot of bikes, even among the professional ranks, with centerpull brakes. When Campagnolo introduced its own Record sidepull brakes in 1968, centerpulls really started fading fast, eventually being perceived by some riders as brakes only for "lesser" bikes, and the Campagnolo design (both the calipers and the levers) became something of a standard to beat.

Also in the late 60s, a new brake design made its debut, although to little notice or fanfare: the dual-pivot sidepull. Originally made by the company Altenburger, and later copied by Weinmann, it was marketed mainly for lower priced bikes and didn't really perform any better than the single-pivots or centerpulls of the day. In the mid-90s, the design was resurrected and improved by Shimano, and now it is the single-pivot sidepull that is the endangered species, and considered by some (unfairly, if you ask a Retrogrouch) to be the "lesser" brake.

The modern dual-pivot brake has just one primary advantage over the single-pivot design: more mechanical advantage. What that comes down to is that one can reach full braking power with less effort at the levers. Some people describe it as "two finger braking," as one can brake hard only with two fingers, rather than a full-hand grip. On the other hand, the dual-pivot brake doesn't track as well as a single-pivot on a bent or out-of-true rim. Another disadvantage is that many of the dual-pivot brakes, even those with longer reach, don't have as much clearance underneath the arches for fenders.

Although the light touch/strong braking power combination of modern dual-pivot brakes is arguably a good thing, I would be more than hesitant to call single-pivot brakes "lesser" or "inferior" brakes. Here, I'd like to look at notable single-pivot brakes.

A very early Campagnolo Record brake caliper, likely from
1970. The 1968 set had no name engraved on the arms.
Campagnolo Record: As I've mentioned above, when this brake was introduced in 1968, it became the benchmark for high-quality side-pull brakes. In addition to their superior materials, finish, strength, and stiffness, one of the things that made the Campagnolo brakes so nice was the design of the quick release to open the brakes for wheel changes. Many other sidepulls either didn't have a quick release, or the quick release was a simple "open" or "closed" affair. The Campy design was an eccentric cam, which allowed the brakes to be opened a little or a lot, which was a fine touch if someone needed to account for a slightly bent rim while riding. The levers, likewise, were much stronger, smoother-acting, and had better "hand feel" than the competition, and eventually were copied by most other manufacturers for high-quality road brakes. The Campy brakes were originally offered in a "normal reach" configuration (47 - 57 mm, which is more like "longer reach," by today's standards), and later in a "short reach" version. They were produced with only minor changes until about 1987.

Some riders with experience using the old Campy brakes will describe the effort to stop as being pretty hard (no "two-finger" braking with these!). But I find that they are improved tremendously by modern brake pads and low-friction brake cables. Actually, I find that to be the case with most older brakes, at least the better quality ones -- that modern pads and cables narrow the performance gap between single-pivot and dual-pivot brakes by a lot.
Weinmann Carrera caliper.  (photo from
www.classicrendezvous.com with permission)

Weinmann Carrera: Weinmann of Switzerland made many types and styles of brakes (rims, too) and in a wide range of price and quality levels. Their "Vainqueur" centerpulls were pretty much ubiquitous on bikes in the middle price range throughout the 60s and 70s. The Carrera sidepull brakes of the mid 70s and early 80s were their top-of-the-line brakes for performance road bikes -- intended to compete with the Campy Records. In some ways, they were up to the challenge. In some ways, a little less. In other ways, better. In terms of the materials and finish, they were very nice. The caliper arms were thick and nicely finished (far superior to other Weinmann offerings), and a good match for the Campys. The quick release, on the other hand, was not as nice -- essentially a two-position open/close lever.

But the Carreras did have one thing that I believe made them even better than the Campagnolo Records. Weinmann incorporated simple nylon bushings at all the pivots – anywhere metal moved on metal: between the caliper arms, and even at the points where the springs contacted the caliper arms. That little addition made the action of the brakes much smoother, and lessened the lever effort significantly. I actually installed these brakes on a bike that is otherwise fully equipped with modern 10-speed Campy Ergo integrated brake/shifting components. In terms of feel, with modern brake pads and cables, they are almost as light in action as dual-pivots, modulate really well, and made mounting fenders easier than with the dual-pivots I almost used.

Early 80s Superbe brakes - 47 - 57 mm reach. Updated
with more modern pads. There's a 32 mm tire plus fender
fitting under there just fine.
Dia Compe/SunTour Superbe (early 80s): The Superbe brakes from SunTour, which were actually made by Maeda Industries partner Dia Compe, were closely modeled after the Campagnolo Record brakes. There was also a nearly identical version marketed with the Dia Compe name. On the Superbe version, the quick release was, like Campagnolo’s, an eccentric cam design, and the brake levers were almost exactly like the Campy levers. Later, a Superbe Pro version was produced that incorporated a nylon bushing at the pivot, like the Weinmann Carrera, which made their action even smoother. That version also had somewhat thicker arms which likely reduced flex and thereby improved them even more. The materials and finish on these is every bit as nice as the more expensive Campagnolos.

Internal springs, thrust bearings, spring-loaded levers.
Spotted on eBay for mega dollars.

SunTour Superbe Pro – Internal Spring (late 80s): In the late 80s, SunTour introduced their exceptional Superbe Pro brakes with internal coil springs, as opposed to the exposed hairpin-type of spring common on most sidepulls. They were made by Dia Compe, but unlike earlier versions of the Superbe/Superbe Pro brakes, there was no equivalent model with the Dia Compe label. In addition to the hidden springs, these also had stainless steel thrust bearings at the pivot between the caliper arms, making them extra smooth, yet also reducing flex in the system. The levers were also spring-loaded, which balanced the tension with the caliper springs, giving exceptional "feel" to the brakes. Dia Compe and SunTour called it the "BRS" system. Shimano did something similar and called it "SLR." The finish on these was jewelry-like. Today, they have a cult-like status and command top dollar.

Shimano 105 SLR: top dollar brakes for a budget price.
Shimano 105 SLR: The late (great) Sheldon Brown called these "the best sidepull brakes ever." These combined several of the features that improved some of the above-mentioned brakes. With bearings between the arms at the pivot, as well as nylon at the spring contact points, and the spring-loaded SLR levers (that stood for Shimano Linear Response), these had exceptional feel, modulation, and response that were remarkable for a brake at any price --and exceptional for a lower-priced brake. The finish and materials were first rate, too.

After Shimano resurrected the dual-pivot calipers in the 90s, single-pivots quickly started to disappear, to the point where they are almost rare now, and the perception is, at least among some riders, that they are not as good. But some of the brakes I've discussed here can just about match dual-pivots when it comes to brake feel or effort, yet are lighter and offer better modulation -- which on the whole, in my book, actually makes them superior.

Campagnolo's top-line Record brakes - still
available in single-pivot. Campy claims the benefit
is lighter weight and better modulation. I wish they
still had that eccentric cam quick release, though.
In fact, one company that surprisingly "bucks the trend" with its brakes is Campagnolo. While Campy does, of course, offer dual-pivot brakes, they still make a single-pivot option for their top-level component sets, Record and Chorus, which they bill (not surprisingly) as offering lighter weight with better modulation.

So why have dual-pivots swept the industry? Part of it is, no doubt, due to the fact that the industry hypes anything "new" as a major improvement (whether it actually is or not), and many people are happy to swallow that. I suppose for another thing, there is an impression that "two finger braking"-- that is, being able to virtually lock up the brakes with almost no effort -- is somehow desirable. I generally prefer a little more effort with a more linear response, myself. But I also suspect that this desire to be able to get full braking force with minimal effort has something to do with the fact that the riding position on road bikes has changed over the years.

Look at performance road bikes today compared to ten, twenty, or thirty years ago. It used to be that the tops of the bars were just a little lower than the top of the saddle. On a serious road racing bike back then, the difference was probably two inches at most. Now, that difference tends to be greater. Back then, when the bars were a little higher than now, a person rode down in the drops, or "in the hooks" more often, and that position allowed the rider to get a stronger grip on the brake levers. Today, the bars are so low in relation to the saddle, that unless one is really flexible and in really excellent physical condition, riding down in the drops is hard to do for very long -- one's neck and shoulders get strained. People now spend a lot more time riding with their hands on top of the lever hoods, where getting a good full grip on the brake levers is more difficult. Dual-pivot brakes make it easier to get full braking power with the lessened hand force that comes with the top-of-the-hoods riding position. It's just a theory, but that's one thing that I believe has been a driving force in the change.

That gets me thinking that I'll have to look at the changing riding position in a future post.


12 comments:

  1. I've recently purchased an 1985 Raleigh Royal with Weinmann Centrepull brakes. The bike is unused so it still has the original pads. The brakes are plenty pwoerful and will stand the bike on end. Even with non aero brake levers. Maybe it is just what we get used to.

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    1. I agree -- once you lock up a brake, you've reached maximum stopping power, and old-style single-pivot brakes can do that just fine. On old bikes like that one (even unused) I like to upgrade to newer pads, as I think brake pad material is a bit better than it used to be -- and old pads (even if "new-old-stock") can get hard over time, reducing their effectiveness. But I'm with you -- nothing wrong with old brakes.

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  2. Teeny quibble in that you are comapring the crème de la crème of vintage brakes to their modern variants. True, the models you mention were - are - great, but there were many not-so-great that flexed horribly or lacked QRs of any kind.

    And you are absolutely right about riding "on the hoods' requiring brakes with ore advantage. Witness the CX trend to inline levers. Is there any point to drop bars in cyclocross? Is there any point to cyclocross?

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    1. True point -- there were some old brakes that were just junk. But the good ones were proof that the basic single-pivot design was (still is) sound.

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  3. Great post. I recently stumbled upon some Sun Tour Superbe calipers in my dad's garage and was immediately struck by the finish quality. Absolutely gorgeous brakes.

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    1. Yes, those were really nice brakes. The older ones, with external springs, can often be found in nice condition for a decent price today.

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  4. Sorry to post on an older post, but i have a question: how do you center these single pivot brakes. I can more or less make them work, but never really reliably. Sooner or later they start rubbing.

    Especially the Shimano 600 Arabesque that i have on my Gazelle: they brake well enough, but they go out of center every two week or so.

    And for me, if single pivot do the job well, i always found double pivots brakes to be better,in braking power and more importantly modulation, especially on the hoods like you said. But if i think the change of riding position do play a role, its not a big one. Belgians riders were known ride a lot in the hoods back then, having immaculate white bar tape after a ride a pride. A least if the ex-pro (he rode with Ocana) who run my LBS is to be trusted.

    Its one of the innovations that i actually think is worthwhile.

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    1. Centering these often depends on the model. The Campy and some of the better copies had a couple of "flats" on the center bolt, just behind the brake arms. One used something very similar to an axle cone wrench to torque the center bolt just a bit one way or the other. The Weinmann ones shown above used a very small socket-type of tool (it was a little "L" bend tool, almost like an allen wrench, but with a "female" end on it) and it fit onto the front end of the caliper to center it. Keeping them centered is usually done with one of those serrated-tooth washers. The Campagnolo ones were quite good, and the better Dia Compe and SunTour brakes (Dia Compe made them both) tended to copy those.

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    2. Yeah, on the shimano 600 one this is done also with serated washers. On mine it just refuse to stay centered for long. Don't know why...

      Thanks for you reply tough.

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  5. Your comment on a wanting linear response with more effort reflects my view of disc brakes and linear-pull breaks. I generally prefer cantilever brakes over them because of where the 'modulation' is: locking up the wheels requires more effort, so my strong hands won't accidentally do it when I'm spooked.

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  6. I've got the Shimano 105 SLR brakes on my 1989 Peugeot Triathlon. Was a surprise to find bearings deep inside when I broke them down for cleaning. Sheldon Brown wasn't exaggerating, they feel buttery smooth.

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  7. With Single Pivot brakes I always have trouble centering. Either I have the mounting bolt too tight or it's so loose that the pressure from the brake cable pushes it off centre.

    I once spent 14 hrs getting my rear Campag single pivot brake centered.

    Any ideas?

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