I think the TDF guys used to do that for the mountain stages to minimize weight. I don't think we'll see it so much this year because they actually have to add ballast to make the weight limit.

This is how many Campagnolo brakes are sold. It is lighter, modulates better, and arubably doesn't effect actual braking distance. It is my preferred setup.

I have dura-ace single pivot brakes (7400 series) and pretty much they suck at braking. I have a U brake on another road bike (dual pivot with yoke, arms of the brake are crossing themselves in X pattern) and it's a lot better even if the dura-ace have koolstop pads and from 1989, that U brake is from 1973 with original pads and brakes a lot better.

I got used to both, on a road bike you don't brake too often. and when I need to really brake I cringe on both of them with my hand from drop bars not from the hoods and will stop just fine (with raised heart-beat) - that's for the dura-ace single pivot. On that dual pivot "U" is a gentle squish from the drop bars also because you cannot put hands on hoods (it does not have hoods on 70's road brake levers, you cannot put you hands there)

I really loved the feel on hydraulic disk brakes on a friend's MTB but I triple judge traffic condition to more fluent movement and less braking. - a habit from brakeless fixed-gear.

End point: single pivot brakes sucks at braking, at least these tiny reach with small arms brakes (like this DA7400 caliper brakes I have)

*i won't change the dura-ace because of the looks and personal choice - it's a complete set of dura-ace 7400 all over, I don't want to make it a less complete set (it was already hard to change the original dura-ace brake pads with koolstops)

Strange.... When I say I don't like "too much leverage", that means I don't like a soft lever-pull like with dual-pivot brakes. I suspect very few people get to the edge of maximum-braking, they're just after the initial bite and want light levers. I prefer the heavier pull of single-pivots brakes as they're easier to modulate at the limit to keep the rear-tyre skimming off the ground, but not throwing you over the bars. I find it's much more difficult to keep a bike on that edge with dual-pivot levers. For maximum-deceleration and shortest stopping-distances, I always get better performance from single-pivot brakes.

Man, some of the testimony here doesn't gel at all with my experience...

I hope you can take my word for it that I know how to set up a brake. Minimise cable friction, file/grind housing ends, align the pads high on the rim with a bit of toe-in, etc...

Admittedly (I may already have mentioned), I've never really used aftermarket pads. And some of my rims have been hardox over the years, which doesn't help, but not the rims on the bike I first fitted a DP to.

Like I said, night and day. Full-blown, max-G emergency stops from any speed possible for the first time, even from the hoods. Not to mention vastly improved wet braking...

Who's gonna tell me an SP front brake is as good as a DP in the wet? o_O

Regarding the mechanical advantage increase for dual pivots....

It seems to me that;
the left arm, that pivots around the center is basically identical to a single pivot type.
the right arm, with the offset pivot, has more leverage since the cable stop is mounted farther out

but doesnt having two different arms with different leverage cause problems??
why doesn't one side of the rim wear down faster than the other?

Except, there's a fulcrum between the two pivots, where the long arm is lifted against a point on the short arm that's on the other side of its pivot.

I suspect this serves to multiply the leverage; I'd be interested to butcher that element out of a set to see the difference...

Unfortunately I couldn't find a good diagram; this is all I could dig up: http://branfordbike.com/merchant/167...campybrake.jpg (Bugger, it won't link.)

Incidentally, Shimano has completely redesigned the dual-pivot for the 9000 line; the mounting bolt no longer doubles as a pivot - that pivot is moved opposite the other one, and the design features a roller cam. This means the pivots can now be integrated into the frame, dispensing with the mounting bolt and yoke, ala ye olde Weinmann centrepulls.

I think you're making a good case for proper maintenance and adjustment of brakes of all kinds. I've been able to keep the front on the edge of locking & going over the bars in the rain ever since I started riding 30-years ago. That was back when Diacompe 500 and Weinmann calipers were the standard and chrome-plated rims were common. Heck, I can even do that with no-name LeeChi stamped steel brakes on *-Mart bikes. Being able to do that with either 2-fingers or just 1-fingers on the lever doesn't make much of a difference.

Remember, the only difference between single versus dual-pivot brakes is the mechanical-advantage (leverage). That results in a lighter lever-squeeze at the lever for the same clamping-force at the rim. Unless you're an 80-lb old-geezer with arthritic hands, pretty much anyone can squeeze the front-brakes hard enough to send themselves over the bars. In which case, the stopping-distances between single versus dual-pivot calipers is exactly the same; determined by the traction-limit of the front tyre.

I think we're just gonna have to agree to disagree on that score. Even though it's a testable hypothesis that evaporates if disproved, and I maintain I've disproved it by never even looking like going over the bars until my first emergency stop with a DP.

I say you must be making it up; you (effectively) say I can't set up a brake to save myself. Pretty fruitless to continue arguing about it, unless someone's prepared to get scientific about it...

Maybe we can agree that a SP won't be capable of maximum braking unless it's tuned better than I know how...

Have to disagree with you. I have to adjust and road test brakes on a daily basis. Regardless of whatever simplistic theories anyone whant to come up with regarding mechanical advantages, there's still a really wide variation in the stopping power of different brake pads. Some of that is due to the materials used and some of it is due to the age of the pads on the bike. The worst combinations are consistantly found on the older bikes where maintenaince just isn't done regularly and pads aren't changed as long as some rubber is still showing. Some of those brakes won't stop (or even slow down) a bike at any speed even if you used both hands. Not everyone has new cables, or teflon lined housings or top of the line brake pads, or the best quality models. And many people aren't interested in paying for them. In which case, rather than getting the best possible performance out of a system, you can get the worst. And there, any shortcomings in either system are simply magnified. Those aren't brakes - they're just excuses for brakes. You couldn't lock up either wheel no matter how hard you tried.
And that comment gets duly noted on the work sheet.

This is starting to look like another thread similar to 'disc brakes are better than rim brakes'. As a blanket statement it just doesn't work.

Agreed. Some of those brakes flex so much, you can have the pads touching the rim and even when you grab the lever and bottom it out on the handlebar you won't get acceptable stopping power. DP brakes can work really well even when poorly setup with old cables/pads. Many crappy SP brakes barely work when perfectly setup.

I misunderstood you, in light of what you said then I agree with you.

I will tell you that SP brakes will stop just as good in the dry, or WET, as a DP will if using the same pads on the same rims with the same tires and the same weight in a full blown max g emergency stop from any speed in any temperature.

I have both kinds of brakes and used them in all sorts of weather and all sorts of speed, there is zero difference. What effects stopping are the other factors unrelated to whether or not the brakes are DP or SP, the other factors are rims, pads, and weight...and that's it. Some pads do not stop as good in wet weather as others, but that's not the fault of the brake caliper design.

This nonsense about how DP is better for stopping then SP is pure prejudice crap.

If you bottom out on the handlebar then the brakes weren't adjusted right, or the pads were shot. DP brakes if not adjusted correctly will also bottom out against the handlebar. More ignorance....Except when you mentioned crappy SP brakes, yup, crappy ones from Walmart then you win the arguement, but what a unfair comparison, taking a crappy Walmart SP brake design against a Dura Ace DP design, that's like taking a Mustang Shelby GT500 and drag racing a Chevy Sonic and then say: see, all Chevrolets suck.

Prejudice, my arse. It's experience, pal.

What kind of clown would insist that when it comes to the SP design, anything other than the best examples with the best pads are capable of maximum braking using anything like normal strength? The greater mechanical advantage of a DP is kinda obvious when you've only ever used SPs (including some of the best ones), and you bloody well faceplant the first time you use a DP. No bike with caliper brakes I've ridden has had sufficient front braking without a DP there. I've only come across one bike with DPs where the pads were so crappy max braking couldn't be achieved.

Experience. Not that stuff like, you know, geometry and logic couldn't lead you to the same conclusion, though...

Hey, SP fanboi, show me a DP caliper that's crappy enough to flex.

Come on - not all single pivot brakes perform exactly the sane and not all dual pivot brakes perform exactly the same. The Altenburger Synchron from the early 70's was the first mass produced dual-pivot side pull brake and had long arms to provide clearance for fenders. Its performance was no better than center pull brakes at the time.

Probably the biggest reason that dual and single pivot brakes perform well on modern road brakes is that earlier road bikes tended to have wider rims (27x1 1/4 or 27x1 3/8), clearance for fenders, and as a result longer reach brauke arms. Both dual and single pivot brake designs are most effective when targeted for narrow rims and small tires. That lets them use a short brake arm which results in increased mechanical advantage. Which is why you won't find them on touring or CX bikes - they take larger tires and want more clearance.

No.

I have used several dozen different road brakes in the last 40 years, and I still own about 20 of these. I have somehow amassed multiple versions of of Campagnolo, Shimano and Tektro dual and single pivots. Plus I have a 50-pound pail of vintage crap that includes older Record, Superbe Pro etc., which I am sure my kids will throw into recycling within hours after I pass on. The really bad stuff old such as Dia-Compe, Modolo etc. has already found its way into the trash.

Bottom line: There is no overlap in the stopping performance of dual vs. single pivot brakes. The best single pivot brake ever made, the Dura-Ace 7402 is inferior to stopping to the worst dual pivot road brake that I have ever tried, which was a cheap no-name thing that came on a $500 road bike. And the cheap dual-pivot came with substandard cable housing and pads.

Bicycles are simple machines. And the simple fact is that all dual-pivot brakes have longer arms than all single pivots. The Dura-Ace 7400/7402 have the longest arms I have seen on short-reach brakeset, but these are still shorter than any dual-pivot. Longer arms mean more leverage/mechanical advantage, which comes at the expense of longer brake lever pull and a tighter pad clearance. I rather have the mechanical advantage and self-centering of the dual-pivot.

All I can throw into this ring is conjecture based on my few experiences with the types of SP and DP calipers I have used/owned over my few years riding now... the only SP's I own and actually care for, are my mafacs and they aren't usually pleasant to adjust right. The two sets of DP's I do indeed have both setup much quicker and faster, but the cheap ones don't perform as well as the mafac's imo, my 105's however setup faster "feel mushier" but are much better for stopping.

Owned 2 Bromptons [same wheel size, brake reach] Single pivot CLB,
+ Salmon Kool Stop Continentals,
newer Dual pivot, stock Fibrax pads ,seem quite similar..

slipping in a set of KS inserts, forthcoming, .. stay tuned ;)

That's misrepresenting my position.

First, I'm referring to brakes appropriate to a 700c sport bike. I'm referring to all relevant SPs (except maybe the occasional megabuck boutique number being currently made, outside the experience of most anyway). I'm also referring to all short-reach SPs, because even though a really crappy one wouldn't be as good as the best SPs, there's no such thing made.

If you want to look at nasty DPs like this, I'd put $100 on them significantly outperforming equally nasty SPs.

Please, put that stuff in your will to a co-op or something!

I'd say any DP that's performing as poorly as a SP would greatly benefit from cleaning the rim and pads, and maybe look at the cables.


Also, Ima say it again: DP front, SP rear FTW. What would be cool is a retro-styled one for vintage bikes...

You need to quantify "outperforming". What numerical targets are you comparing that determines when one "outperforms" and what other numerical target has to be achieved to consider it "significantly outperforming"?

In our test, let's use:

1. identical bike, both sets of brakes must be used on the same bike in order to control wheelbase, weight, centre-of-gravity height, rider position, brake-levers, housing, etc.

2. identical brake-pads, the exact same pads will be moved from one brake to the other. There are variations between different production runs of the exact same model.

3. identical wheels, rims & tyres @ standardized pressures, again to maintain testing controls and reduce the number of variables

4. standardized test procedures. A test protocol needs to be created, ideally something repeatable day-after-day without too many variations in ambient-temperatures, humidity, etc. And correction factors needs to be determined for changes in those conditions.

Yeah, sure, all that by the simple expedient of swapping the brakes rather than comparing two bikes.

But I can't see one of us bothering. Are you willing to put money on it, though?

Never mind the nasty brakes; those long reach DPs are thin on the ground.

Shimano's SLR brakes from when they were making both would be a good comparison, right? This is the original disagreement anyway. They were about as good as SPs ever got... I'm sure I could dig up a 600 one; I'll pit it against RSX just to rub it in.

BS, all BS. I can face plant easily with any of my SP brakes. Keep in mind I don't own any cheap versions of SP brakes. You sir have no experience with SP, just trying to sound like you do, but your not alone.

Yet SP may be fit for the job, it has less mechanical advantage. So SP on a heavy tourer bike may not be enough, even DP have limit then it comes in the V's/cantis/ hydraulic on rim, disk (in various versions of actuating and diameters, etc). And the fact that each principle may be overengineered to provide whatever mechanical advantage you need, some are easily scalable like disks and drums because depending on caliper diameter disk ventilation you may stop a bike or an 18 wheeler.

But as far as what I ride, cheap "U" brake with brick hard pads (original from the 80's) surpass my SP dura-ace either with DA pads or KS, in terms of mechanical advantage and feel and capabilities. With the SP DA I cannot lock the rear wheel if I'm seated, while with "U" i have controlled skids as I please at a flick on the lever.

I have no problems with the vintage "crap" side pull brakes on my bikes. Dual pull may have better leverage, but the limiting factor is wheel lockup in either case. It doesn't matter how much better the leverage is once the wheel stops turning.

Perhaps those people who have problems with traditional side pulls are substantially heavier than those of us who don't?