Why no love for direct mount rim brake?

[maxxevv]

It adds weight to the frame though.

[Hexsense]

It adds weight to the frame though.

you are probably right.
Instead of single hole to resist push (rear brake) /pull(front brake) force.
Now it's two holes that get half the load of push/pull force. Then a bit of extra force side way to keep stay at their place.
But i'm not sure how significant it is.

[Pokerface07]

My Emonda has the rear direct mount brake in the traditional location. Far batter than under the BB (like on my Foil).

[froze]

Just month ago a friend bought a road bike with disk brakes so we decided to test the stopping ability of his vs mine with the Koolstops, he felt for sure his were going to be better. So we did 3 test at 20 mph and 3 at 25 mph, in all
6 tests we were equal to within a foot, sometimes I stopped quicker and sometimes he did (which I'm sure is due to reaction timing) but never was either of us more than a foot difference. While it wasn't raining when we did the test, perhaps in the rain he might have a slight advantage, but not sure if that's true since the KoolStops have an instant response even when wet compared to Shimano which were slow to react when wet; I am also pretty sure from my experience with Shimano pads that had the test been done with those pads on he probably would have stopped quicker in all the tests. So yes good rim brake pads like the KoolStop Salmon makes a big difference dry or wet.

What kind of disc brakes was your friend using ? Cable actuated or full hydraulics ? There is a big gap in modulation and control and to some degree power between the two types.

He had hydraulic, can't recall the model, some number he rattled off, but they were Shimano, but he had Shimano Di2 Ultegra so I can only assume the brakes were of that level as well since he said he decided he wanted full Ultegra when he bought his new bike.

Keep in mind the test that we did was on my bike equipped with 105 brakes, and my wheels were heavier than his, he had Ultegra AL wheels and I have the lowend RS501-30 AL wheels, so even with my heavier wheels the stopping distance as indicated. His bike overall was about a pound less than mine and he weighed darn close to me from what he said, so I don't think weight was an issue, not sure if my wheels weighing about 400 grams more than his would make a difference as long as the total weight is about the same. He was using Conti GP4000s 700x25c all around, I was using Hutchinson Intensive 2 tires 700c x25 on the rear and 23 on the front. Again without a full on scientific study of the exact weight, various tire differences including PSI, and wheel momentum, one riders experience at stopping vs another, and whatever other variable you can think of, the test is what it is...done by amateurs!

I believe that stopping is completely dependant upon tire adhesion to the surface conditions, once you reach the limits of adhesion then the tires will lock up. The other rider and I were actually having that discussion before we decided to test our brakes to see who was right, because all he was doing was rattling off marketing mumbo jumbo he had read and was being told, scientifically however it's all based on tire adhesion, and I proved that point to him which shocked him as to the results.

Cheap sidepull brakes had flexy arms, like Walmart type of bike, but once you get into mid to highend that flexiness goes away, and completely negates any differences. I can also guarantee you that if I took my high end older Suntour Superbe side pull single pivot brakes against the guy with the disk brakes the results would be very close to the same. I heard this nonsense for a long time when dual pivots came out that they stopped quicker than single pivots, not true, especially with the high end silky smooth Superbe brakes; and the same is now true with disk brakes. it's all marketing.

However keep in mind, I'm only talking about AL wheels, this information I've been discussing does NOT apply to CF wheels.

[maxxevv]

I believe that stopping is completely dependant upon tire adhesion to the surface conditions, once you reach the limits of adhesion then the tires will lock up. The other rider and I were actually having that discussion before we decided to test our brakes to see who was right, because all he was doing was rattling off marketing mumbo jumbo he had read and was being told, scientifically however it's all based on tire adhesion, and I proved that point to him which shocked him as to the results.

Cheap sidepull brakes had flexy arms, like Walmart type of bike, but once you get into mid to highend that flexiness goes away, and completely negates any differences. I can also guarantee you that if I took my high end older Suntour Superbe side pull single pivot brakes against the guy with the disk brakes the results would be very close to the same. I heard this nonsense for a long time when dual pivots came out that they stopped quicker than single pivots, not true, especially with the high end silky smooth Superbe brakes; and the same is now true with disk brakes. it's all marketing.

However keep in mind, I'm only talking about AL wheels, this information I've been discussing does NOT apply to CF wheels.

You missed the point.

It isn't about absolute power. Its about finesse of control that's possible with quality hydraulic brakes.

[Marin]

1) I can do stoppies / lift the rear wheel while still rolling with my (standard mount) rim brakes. This is the ultimate test of brake modulation - I don't need anything better.

2) I can do these on my newer carbon rims. Braking on these is excellent, better than on aluminum for me.

3) I can't do stoppies on my old (2012) carbon rims because braking on these is not as good and I need too much force at the lever.

Conclusion: I don't need or want anything other than normal, stiff, light rim brakes with a good pad/rim combo.

I run Ciamillo, SRAM Force and mid-level Tektro calipers with blue compound carbon pads or Shimano R55c4 for alu.

[jeffy]

.... and another thread descends into "disc brakes are unnecessary! rim brakes are just fine!!!" nonsense.

[pdlpsher1]

Those who have never tried a DM brake should try it. It's really good and I would never go back to regular brakes. On your next frame purchase one should look for DM brakes but avoid those with BB mounted rear brakes.

It makes my eyes hurt when I see that big gap between a regular brake and the frame/fork. It looks so old school now that I'm used to my DM brakes

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[maxxevv]

.... and another thread descends into "disc brakes are unnecessary! rim brakes are just fine!!!" nonsense.

And yes... I never understood why people are so adamant about their state of assertion either.

But back to topic ... direct mount brakes are indeed better than most dual pivot brakes if properly implemented.

[fromtrektocolnago]

any issues with mud and rain vs standard caliper brakes? thought they're more sensitive to grit and mud. please correct me if I'm wrong

[fromtrektocolnago]

.... and another thread descends into "disc brakes are unnecessary! rim brakes are just fine!!!" nonsense.

And yes... I never understood why people are so adamant about their state of assertion either.

But back to topic ... direct mount brakes are indeed better than most dual pivot brakes if properly implemented.

In the old days there was Godwin's law

[pdlpsher1]

Due to the tight clearance between the DM brakes and the frame/fork, I have issues with small gravel getting caught in that small space. This requires me to do a full stop and dislodge the rock before continuing. I don't ride on gravel roads. This happened to me when I rode on freshly chip sealed roads where the loose gravel is sticky with tar, and the small gravel get carried up to the DM brakes by the tires.


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[froze]

I believe that stopping is completely dependant upon tire adhesion to the surface conditions, once you reach the limits of adhesion then the tires will lock up. The other rider and I were actually having that discussion before we decided to test our brakes to see who was right, because all he was doing was rattling off marketing mumbo jumbo he had read and was being told, scientifically however it's all based on tire adhesion, and I proved that point to him which shocked him as to the results.

Cheap sidepull brakes had flexy arms, like Walmart type of bike, but once you get into mid to highend that flexiness goes away, and completely negates any differences. I can also guarantee you that if I took my high end older Suntour Superbe side pull single pivot brakes against the guy with the disk brakes the results would be very close to the same. I heard this nonsense for a long time when dual pivots came out that they stopped quicker than single pivots, not true, especially with the high end silky smooth Superbe brakes; and the same is now true with disk brakes. it's all marketing.

However keep in mind, I'm only talking about AL wheels, this information I've been discussing does NOT apply to CF wheels.

You missed the point.

It isn't about absolute power. Its about finesse of control that's possible with quality hydraulic brakes.

No, I think you missed the point. The discussion on any bicycle site or magazine or marketing ad is that disk brakes stop faster, this isn't true. And on your point of finesse pro racers for years, and little non pro racers like myself (former) never had any issues with finessing our brakes. This is the same finessing nonsense that was spoken of when the conversion went from single pivot to dual pivot, it's imagination running wild. Man has a way of wanting to find something so bad they will see it even though what their looking for is not there. Good example, weird shapes found on Mars being described as man made; now come down to earth and we have marketing forces wanting us to buy disk brakes and are going out of there way to tell us it's better leading people to believe that it is better and will think that to be the case because it has to be the case to justify spending the money.

Look, when my friend and I did our test do you not think we had to finesse our brakes? of course, we had to be right on the edge of locking up and going out of control and losing the brake test. So the both of us finessed our brakes to their maximum capability to stop the bike in the shortest distance possible.

Again in some cases disk brakes are good, but for the most people riding AL rims on a road bike it doesn't make sense.

[fromtrektocolnago]

that would be a very good reason for not wanting to get a pair in my book. I would not want to stop and remove gravel from the brakes.

[pdlpsher1]

that would be a very good reason for not wanting to get a pair in my book. I would not want to stop and remove gravel from the brakes.

The problem only occurs when the gravel is sticky. If you ride normal gravel roads there's no chance for the gravel to end up near the brakes due to gravity.

There are more reasons to not get one....like the cost of a new frame. But if you are shopping for a new frame anyways why not consider as an option? And the DM is not about weight savings. It's about being aero, better modulation, higher power (leverage), zero chance for going out of center, etc.