Would someone please explain direct mount brakes?
#1
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Would someone please explain direct mount brakes?
What are they? Who makes them? Trek says they eliminate redundant parts. Maybe so, but in the picture they show it appears the redundant parts are replaced with a pants-load full of new, unique parts. What is the advantage of that?
#2
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The idea was to remove the bars across the back of the brake. The best comparison I can think of is center pull brakes vs roller cam brakes.
The extra parts I believe are for extra clearance so they're a red herring. Consider that there'd normally be a very rigid aluminum or maybe carbon? piece holding the two mounting posts. You save that with the direct mount brakes.
No matter what the complicated mechanism above the brake, the direct mount frame saves the bar that would hold the two mounting posts.
The extra parts I believe are for extra clearance so they're a red herring. Consider that there'd normally be a very rigid aluminum or maybe carbon? piece holding the two mounting posts. You save that with the direct mount brakes.
No matter what the complicated mechanism above the brake, the direct mount frame saves the bar that would hold the two mounting posts.
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#4
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Right, or in the back either the chainstays or the seat stays act in a similar manner.
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#5
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To expand a bit, until dual pivot side pull brakes were popular there was no reason to have direct mount brakes - the bolt going through both arms also held the brake on. There were two aluminum arms on each brake, one for the left, one for the right.
With the advent of dual pivot, i.e. a pivot on each side of the brake, there was a third aluminum arm, the one that holds the two posts.
In this stock picture (from CC in this case) the third bar is visible in the front brake. The rear brake is the old style side pull brake. The dual pivot brake uses the center bolt as one pivot and a second offset pivot as the second. The latter gives more leverage than the center bolt so ideally you'd want two offset pivots, aka like an old style center pull brake.
With a direct mount brake you get the better pivot placement and no extra material on the brake. I figure the frame/fork would need a bit of reinforcement to resist flexing, just like when V-brakes were originally introduced - if you retrofitted V-brakes on a lighter regular-cantilever brake frame you could see the seat stays flexing out as you applied the brakes. Once frames got reinforced the V-brakes worked fine, but on older non-V-brake designed frames the V-brakes did not improve braking.
With the advent of dual pivot, i.e. a pivot on each side of the brake, there was a third aluminum arm, the one that holds the two posts.
In this stock picture (from CC in this case) the third bar is visible in the front brake. The rear brake is the old style side pull brake. The dual pivot brake uses the center bolt as one pivot and a second offset pivot as the second. The latter gives more leverage than the center bolt so ideally you'd want two offset pivots, aka like an old style center pull brake.
With a direct mount brake you get the better pivot placement and no extra material on the brake. I figure the frame/fork would need a bit of reinforcement to resist flexing, just like when V-brakes were originally introduced - if you retrofitted V-brakes on a lighter regular-cantilever brake frame you could see the seat stays flexing out as you applied the brakes. Once frames got reinforced the V-brakes worked fine, but on older non-V-brake designed frames the V-brakes did not improve braking.
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Thanks, that explains it. So the Emonda frames are drilled for the direct mount brakes. Are all the major brands offering them? Are the fork and brake bridge area on the Emonda or other newer bikes also drilled for regular side pulls and dual pivots?
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1) Not sure. Some newer frames (eg. 2015 Aeroad) have them but they're far from common. There are still too few options for direct mount brakes ATM.
2) No, afaik they're mutually exclusive mounting designs.
2) No, afaik they're mutually exclusive mounting designs.
#8
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Right now it's a smaller number of frames but I think that we'll see a larger number of them in the future.
It's like threadless fork/stem set ups - when they were first introduced everyone was saying "well it's not worth it" to get rid of quill stems. That design also had duplicated efforts with the quill inside the steerer and long bolts holding stuff together. Now quills are quaint antiquated things that seem inefficient compared to the very simple "clamp the steerer with a few short bolts" threadless stem system.
Likewise BB/crank interfaces have gotten rid of the heavy solid steel BB axle, the two big bolts (typically steel) holding the arms to said axle, etc. With the newer stuff (I have a set of FSA cranks as well as Cannondale SI sets) it's one bolt that's smaller/lighter or even no steel anything except maybe bearings (BB30).
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Shimano offers direct mount calipers in 105, Ultegra and Dura-ace. Pick your poison
#10
Flyin' under the radar
#11
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Virtually every review of direct mount brakes is that they are lighter, stronger and better modulation than the previous generation of dual-pivots. I suspect they will be standard in a few years.
#12
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They also reportedly have better tire clearence. It would be fantastic if most racing frames could use 28s, or fenders. They seem like an actual good idea. Not a big deal either way.
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Here's the Emonda SLR front fork with the bungs for direct mount brakes.
#14
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Agreed. No shortage of change just for the sake of change in the bike industry but there does look to be some real upside here. Of course there's also the movement to disk...
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Of course, before the Dual Pivot brakes, there were the Center Pull brakes.
And, apparently they modified the design with an early braze-on.
Is there anything truly NEW in the bike world?
And, apparently they modified the design with an early braze-on.
Is there anything truly NEW in the bike world?
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Doesn't look like they have much more clearance to me. For a two post setup I'd rather have regular v brakes. More clearance and a simpler design. Weight seems to be around the same. Not sure how these direct pull brakes are better than V's.
#19
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That doesn't make a lot of sense. They'll just start making direct mount brakes themselves. Seems unlikely that it's an attempt to shut anyone out.
#20
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Conventional v-brakes are difficult to make road levers for. I suppose mini-v brakes are a solution to that, but the other problem with v-brakes is that they just don't modulate as well as calipers.
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Exactly what I was thinking when I first saw a direct mount brake. But that would allow me to use the $12 926AL solution, and Big Carbon can't allow that!
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Modulation isn't an issue at all. The problem with current mini-v designs is that it's hard to get them unhooked for a wheel change. But that could be fixed with a little engineering.
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For the brands listed, Planet X is a bike manufacture, not a brake maker, they will follow the industry for brake mounts, KCNC have plenty of other product lines, and aren't a pure brake maker.
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How is another form factor for brakes shutting anyone out? if anything, it's giving aftermarket suppliers a chance to increase their product line, and bring more innovation to the market.
For the brands listed, Planet X is a bike manufacture, not a brake maker, they will follow the industry for brake mounts, KCNC have plenty of other product lines, and aren't a pure brake maker.
For the brands listed, Planet X is a bike manufacture, not a brake maker, they will follow the industry for brake mounts, KCNC have plenty of other product lines, and aren't a pure brake maker.