Dual pivot vs. single pivot brakes
 

Those who have read my recent posts know I'm working on improving the braking on my old Trek 1400. It currently has old single-pivot 105 brakes that, for what should be midrange quality, are rather whimpy and the brakes as a whole rather mushy. I came across a pair of Shimano RX100 dual pivot brakes that look and feel a bit beefier. Would someone please fill me in on the advantages of dual pivot over single pivot? I'm switching from the old hard anodized rims to some Alex double wall with machined braking surfaces and have replaced all cables and housings being very careful about bends and loop length. So far the stopping has gone from downright scary, to reasonably acceptable. Would replacing the single pivot with the dual pivot brakes likely improve stopping, both overall and modulation, even further?

Short answer is, yes. Dual pivots have more mechanical advantage because the lever arms are longer. So you get more compression on the rim for the same force on the brake levers. Brake shoes can also make a difference as well, and in general, more modern dual pivots, even on the low-end models will have much nicer brake shoe compounds than the brake blocks from the 1990s. So if you upgrade to dual pivots, you get the benefit of more MA. But if you also upgrade to more modern brake shoes, that's a double whammy.

You don't need to pay a lot for a brake upgrade. Check out BikeWagon.COM and the Tektro R466-E brakes. Around $25 per set. Nice brakes that stop great. I swapped out an old set of BR6400 (Older single pivot Shimano 600 Ultegra from the late 80's) and put on a set of these, and braking is dramatically better. Plus they look good too.

Agreeing with gyozadude, the short answer is yes, but it can get a fair bit more complicated. I find that the biggest factors I've noticed are with the quality of the pads, and the rims themselves, not so much the caliper(assuming it is at least of decent quality), though the dual pivot design has better mechanical advantage. An example of something to consider is the Planet-X ultralight brake caliper which is a single pivot, and stops better than my modern 105 dual pivots. You should consider cleaning your rim sidewalls and checking your pads for ... well stuff stuck in them, as well as making sure they aren't glazed over (sand them down a bit if they are), and that'll make a big difference. I find most people don't clean their braking surfaces, which doesn't make sense, seeing how big a difference it always makes and it could save your life.

The best braking performance I have ever had was with an old set of Matrix ISO rims that had some sort of coating on the sidewalls... and those things would flip me over the handlebars without much effort (Yes, I did do this twice by accident), but the coating eventually wore off. Also, machined sidewalls doesn't necessarily mean better braking performance, especially if you don't clean them, as they tend to accumulate tons of crap.

Something to consider also is the brake lever itself may just suck. If the ergonomics aren't right, you it'll be harder for you to apply the same force to the lever, so a decent set of levers do make a difference.

It depends. Both dual pivot and single pivot brakes come (and came) in different qualities. Some are junk and some perform very well. In theory a dual pivot design has more mechanical advantage. In reality - if you can't pull the levers hard enough to stop - its probably for some other reason altogether. Good quality brake pads make a HUGE difference in stopping power assuming you're already using a decent brake. Dual pivot brakes are easier to center, single pivot brakes are lighter. Currently I have two road bikes - both with 2011 Ultegra brake pads. One runs 2011 Shimano Ultegra dual pivot brakes and 1995 Mavic Cosmic Elite wheels, the other runs 1988 Shimano 600 Ultegra single pivot brakes and a 2008 Shimano Ultegra wheelset. Braking performance is virtualy identical.

dont bother changing the rear.

Aero levers if it doesn't already have them help too.
My old 88 1000 had Shimano SLR single pivots (similiar to 105) and they worked pretty good. Way better than the dia comps on my other vintage bikes but not as good as the Ultegra duals I put on my latest vintage Trek.

This is interesting. I have a shimano 600 dual pivot on the rear of my Pug, but, I also have single pivot Dura Ace that I could use. Could it be that the DA single would do as good or better job than the 600 dual, and add less weight to the bike?

He says this because a decent single pivot brake with good pads is typically more than enough out back. I have 2 road bikes with single pivot rear brakes. Oe is a vintage monoplanar and the other is a modern record caliper paired with a dual pivot on the front. I use the same pads in each and the bikes share wheelsets. Both bikes have enough braking power to lock up the rear wheel without requiring a lot of hand strength. A more powerful brake would just be added weight.

How well do you like centering your brakes?

Once you switch to dual pivots, you won't get the opportunity to do that again.

I have never understood this argument. Good single pivot brakes will stay centered for thousands of miles and both single and dual pivot brakes need centered on installation.

Yup - key word is GOOD single pivot brakes. Which are a better bet than cheap dual pivot brakes anyway.
Single pivot brakes also deal with an out-of-alignment rim much better than dual pivot brakes.

Maybe something else to note is brake reach. That can limit whatever brake can be swapped over on a frame. For example - a Cannondale Synapse with long reach Tektro R539 dual pivot brakes may have clearance for fenders, but it would be impossible to mount anything short reach - like Ultegra dual or single pivot brake assemblies. the longer reach also trades off mechanical advantage, so a shorter reach single pivot could have the same 'feel'.

This braking stuff is a bunch of nonsense!

I have dual pivot, single pivot, linear pull, and center pull cantilever brakes. And I can attest that if you have the same tires, same rims, same weight factors, same road conditions, all brakes adjusted to factory specs with new pads on all four different brake systems, they will all stop the bikes in the same amount of distance.

If you riding as a larger clydesdale, or touring with a heavy load, or tandem riding, then single and dual pivot design is not the best type of brake to use because the calipers can flex hindering braking efficiency and this is why the cantilever was invented for, but now disk brakes have come along which do even a better job with heavy loaded bicycles. Technically a cantilever is a dual pivot but it uses way shorter caliper arms with each are attached to the fork sides rather then one central mount and thus the flex is reduced significantly.

What I don't like about dual pivots is that lessen ability to modulate the brake vs the others, and dual pivots cannot track a out of true rim as well as single pivots. Also dual pivot brakes are a bit heavier then single pivot designs if that's worth anything. When I say dual pivot here in this paragraph I'm not referring to cantilever, the cantilever design will easily track a out true rim because of it's dual mounting system, single mounting hinder this ability in regards to dual pivots.

Find some old TDF videos. Centering brakes on-the-fly during the race used to be a quite common service.

Maybe you are going back too far. Its not an issue with my 80s campy monoplanars, my 90s dia-comps, or my 2000s era campy record brakes. The latter has not been adjusted in 3 years despite thousands of miles, a RAGBRAI, being shipped, and being thrown in a trunk multiple times.

Might be. I have a way of remembering things from decades ago as having happened only year or two back.

On the other hand, I've got extensive experience working with "bread and butter" bikes. Before dual pivot brakes, keeping the brakes centered was a constant PITA. Brake pad replacements were more frequently necessary because one side always wore out way before the other. Now it never even blips the radar. I'm sticking with dual pivots for my personal bikes.

Thanks for all the responses. The deed is done. The RX100s are on, centered, and new Ultegra all weather pads installed. The front wheel has been changed to one with Alex doublewall alloy rims with machined braking surfaces that show almost no wear (bought these wheels from a bike co-op in pristine condition). The only thing left to do is swap rims on the rear wheel retaining the original 7-speed hub. As it is, the braking is substantially improved. The next time it needs bar tape, I might consider swapping levers to see if that helps as well.

I like firm feeling, well modulated brakes, hate mushiness.

Good choice. I have a set of RX100 dual pivots, plus all kinds of single and dual pivot brakes. I own Campy brakes from Chorus to Mirage and everything in between. I have Shimano from Dura Ace to Exage. Plus several types of Tektros. All of the dual pivots are better than all of the single pivots. There is no overlap in braking performance. And the RX100s, when properly set up are as good as anything in my fleet. The only way to improve the performance would be to add some Scott pads. This was the setup I was riding today - worked great.

So Dave, if you were given the choice between RX100 duals and Dura Ace singles, you would pick the RX100s? That's basically the decision I have to make.

Dave those RX100's are long reach which reduces the mechanical advantage of a dual pivot system, so you might want to review your 'There is no overlap in braking performance' impression. Personally I'd opt for the DuraAce single pivots with 2012 DuraAce pads in a flash myself.

How do those 2012 DA pads wear? I'm assuming that they're high performance, but, may not last very long, eh?

Thats a tough question to answer. Not too many people running DuraAce are commuting in the rain or touring with heavy loads so it would be hard to get that kind of data to stack up against something like CoolStop. From personal experience on a stripped down road bike, where brakes are used more to scrub off speed than to come to a screeching stop, I can say that they'll easily last a season and that they perform exceptionally well in the rain.

Everything is relative - my downhill buddies typically go through 10 sets of high end disc brake pads a season. Is it because they wear fast - or because some of these guys are world class riders and are just pushing the equipment past their limits?

We used to center our brakes while we were cruising down the road because it looks cool. Especially the rear. I think that's why the aforementioned TDF guys did it.

I'm confused, I have a feeling your an impostor or you had cheap side pulls. Almost all of my road bikes are side pull brakes from the 80's, only one bike has dual pivot, one has cantilever. One of my bikes with the Superbe side pulls has over 160,000 miles on it and those pads do not wear out faster on one side, and neither do the other pads on the other sidepulls I have on my other bikes. And the brake pads I've been using for the Superbe has been the orange (salmon) Suntour Superbe pads of which I have several sets in stock; those pads last a very long time, in fact their out lasting the stock Campy pads that came on the dual pivots on my 07 Mercian and the Suntour pads have easily 7 times the mileage with no signs of wearing out!

And for the others, the side pulls rarely have to be re-centered, but neither do the dual pivots, the cantilevers for some reason seem to go out of adjustment more frequently. But those Cantilevers have the original Dia Comp pads and they seem to last a long time too, and those pads on some weekends carry an additional roughly 30 pounds of weight.

Mathauser use to make a really nice solid orange (salmon) rubber pad that also lasted a very long time, in fact the Suntour's are similar in looks which makes me wonder if their actually made by Mathauser.

I think the point was that on the newer dual-pivot brakes, even the rather cheap ones work very well. Compared to the old single-pivot sidepulls where you had get pretty high end stuff to get acceptable performance (a noteable exception being the Shimano SLR single-pivot calipers, before they switched to dual pivot.)

I don't run any dual pivot brakes but will admit that in many cases they can greatly improve breaking performance if the previous brakes were lacking... whoever made a point about the levers having an effect was dead on as sometimes a change in levers can greatly improve braking because of better mechanics in the lever that compliments the brake.

My friend's Bianchi was equipped with a Victory group and single pivot brakes which were only so so until I switched the levers to a pair of older Record levers I had and the braking performance went from blah to stellar.

The Victory levers work just fine on my road bike and are mated to some Zeus titanium centre pulls that have awe inspiring stopping power.

Just upgraded my Proctor road bike to some 600 Tri Colour and installed the single pivot 600 brakes and the stopping power is excellent and this is with older brake pads.