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Old 01-19-10, 11:51 PM   #1
invitapriore
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what are the advantages of dual-pivot caliper brakes?

I'm not really sure why dual-pivot caliper brakes exist. They seem unnecessarily big compared to single-pivot models. Are there advantages I'm not catching on to? Clearance? Mechanical advantage?
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Old 01-20-10, 12:59 AM   #2
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Leverage. Mechanical advantage. All the benefits of a center-pull caliper without the cable stretch and flimsiness.
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Old 01-20-10, 01:59 AM   #3
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Mechanical advantage/leverage from the lever to the pad does not change a whole lot between styles of brake. Dual pivots are a little higher leverage then older side pulls, but their main benefits are they are much better at staying centered (so you can run tighter pad clearances, so less slack when you squeeze the lever) and they are stiffer (because they are fatter.) Stiffness seems to matter more than simple leverage.
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Old 01-20-10, 04:57 AM   #4
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For me their main advantage is that they require less lever effort for the same braking force. It really is noticable. It may mean little if you're in the drops and can work the levers from the spot farthest from the pivot but if you're up on the hoods a lot as I am and your braking effort on the lever takes place close to the pivot point the extra leverage at the caliper makes a big difference.
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Old 01-20-10, 08:47 AM   #5
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For me their main advantage is that they require less lever effort for the same braking force. It really is noticable.
+1 Both single and dual pivots have the same ultimate braking power, i.e. either type can lock both wheels. However, the reduced hand pressure required by dual pivots for a given level of braking is certainly appreciated on long, winding downhills where you have to control the bikes speed for a long time.

Their ease of centering and ability to remain centered is a major plus.

I've used both types extensively and would never willingly go back to single pivots.
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Old 01-20-10, 09:39 AM   #6
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but their main benefits are they are much better at staying centered (so you can run tighter pad clearances, so less slack when you squeeze the lever)
Their increased leverage comes at a cost of less pad "throw" which requires that the pads be set closer to the rim for correct operation. In reality, this is actually a disadvantage as rims must be kept truer to avoid pad rub and wheel changes are more difficult with wider tires (for a given rim width).
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Old 01-20-10, 10:10 AM   #7
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Their increased leverage comes at a cost of less pad "throw" which requires that the pads be set closer to the rim for correct operation. In reality, this is actually a disadvantage as rims must be kept truer to avoid pad rub and wheel changes are more difficult with wider tires (for a given rim width).
Sure, there is no free lunch. However, I'll gladly pay this cost for less effort at the lever and better centering. Keeping wheels adequately true isn't that big a deal and, unless you are using very wide tires on narrow rims, the qr on the brake calipers have always been adequate.

One way to get easy wheel removal/installation even with wider tires is to use Campy Ergos or Tektro brake levers with Shimano or SRAM or Tektro brakes. That way you have a qr on both the caliper and the brake lever/brifter and the pads really open wide.
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Old 01-20-10, 11:13 AM   #8
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HillRider, I agree about the advantages outweighing the disadvantages. I was merely pointing out a flaw in the post.
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Old 01-20-10, 11:30 AM   #9
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I notice that I can use my hand to move the brake set either to bias to the left or right. Is it suppose to do that? I've tightened the bolt as much as I can already.
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Old 01-20-10, 11:36 AM   #10
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I notice that I can use my hand to move the brake set either to bias to the left or right. Is it suppose to do that? I've tightened the bolt as much as I can already.
DP brakes can be moved and centered by hand but shouldn't move easily. If you have recessed nut mounts, it's possible the nut is a bit too long and is running out of threads on the brakes' center bolt before getting adequately tight.
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Old 01-20-10, 01:07 PM   #11
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I was riding single pivots on my classic (Suntour Superbe) and switched to double pivots (Ultegra 6600). The difference was dramatic, all of a sudden the bike could stop going downhill. I also really like how easy they are to center (one screw to adjust), the old single pivots were a royal pain in the you know what to adjust.

Also just because your bike can lock up the wheels doesn't mean everyone's can. My old steel 22lb bike with it's 185lb rider most certainly could not lock it's wheels with single pivots and my grip strength (as a long term weightlifter) is stronger than most.
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Old 01-20-10, 01:34 PM   #12
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DP brakes can be moved and centered by hand but shouldn't move easily. If you have recessed nut mounts, it's possible the nut is a bit too long and is running out of threads on the brakes' center bolt before getting adequately tight.
It takes effort to move the brakes. It's not like it's lose. But I find it weird that I can move it to align it to the centre.
In regards to nut mounts, now that you mention it, during installation I ended up with an extra washer. Perhaps I should put it in too. Don't know why I left it out. Should it go together with the 1st washer? Or at another place?
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Old 01-21-10, 12:17 AM   #13
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One of these days, I'll make a video showing how to center single-pivot brakes. It's really not hard.

I have a bike with single pivot (Campagnolo Record) and a bike with dual pivot. Each has its advantages, but the single pivots work just fine.
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Old 01-21-10, 12:38 AM   #14
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It takes effort to move the brakes. It's not like it's lose. But I find it weird that I can move it to align it to the centre.
In regards to nut mounts, now that you mention it, during installation I ended up with an extra washer. Perhaps I should put it in too. Don't know why I left it out. Should it go together with the 1st washer? Or at another place?
Don't randomly add washers to it. The initial washer is to give the caliper some bite into the frame - precisely so that it doesn't rotate easily once the recessed nut is up to torque spec. You only need to add the more spacers if the brake shoes are not clearing the frame when properly adjusted.

Dual pivot calipers are SUPPOSED to be centered by hand. The 'centering screw' increases spring tension and moves the pads down at the same time. 99.9999% of the time it is not necessary to use the screw.
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