Direct mount brakes

[nortx-Dave]

I'm considering a new custom road frame and want to use rim brakes - for various reasons.

What's the consensus when it comes to direct mount brakes?

I live in the rolling terrain of North Texas and I don't descend mountains......nor ride in wet conditions - if I can help it.

Overkill? Marketing hype? Just a trend?

[Blue Jays]

That is precisely the same braking system I am considering for my next steel custom bicycle.

[bikinchris]

Direct mount brakes are totally unnecessary. There is no reason for them to exist. They don't do anything better than conventional brakes. Nor do they do it worse. Except if you are a rider who rusts things, they become harder to adjust than conventional caliper brakes. There is not a wide range of models available and with the intrusion of disc brakes, getting parts or replacements for them in the future might be a problem.

[FlashUNC]

Better tire clearance. If you want tire clearance on short reach calipers, direct mount is the way to go.

[Blue Jays]

"...Better tire clearance. If you want tire clearance on short reach calipers, direct mount is the way to go..."
Agreed. I figure between deteriorating roadways and increasing age...a little extra tire volume might be nice.
For riders with an ample supply of sweet wheels already built, this approach might be the "sweet spot" for utility.

[pinoymamba]

very necessary.

https://live.staticflickr.com/65535/48824630943_44ff73eca2_c_d.jpg

[nortx-Dave]

But aren't there "regular mount" caliper brakes that will fit wider tires - up to 30c say?

Like Cane Creek's eeBrake.

[pinoymamba]

Yes.
https://live.staticflickr.com/65535/49330498487_9c467f9d6e_c_d.jpg
https://live.staticflickr.com/65535/49329817803_81cea2bf38_c_d.jpg

[nortx-Dave]

Very nice Bishop! But that's a direct mount eeBrake. Is it substantially better than the "regular mount" eeBrake?? I mean they both fit equal sized tires, right?

[one60]

Beyond the improved clearance, DM Campy brakes offer independent adjustment for each side and in my experience stay 'centered' better than traditional rim brakes when removing/installing wheels. A minor advantage but noticeable. Also, though I can't prove it, my DM brakes seems to have more power than traditional mounted Rev+ era Campy brakes. There's no obvious downside, so why not?

[FlashUNC]

But aren't there "regular mount" caliper brakes that will fit wider tires - up to 30c say?

Like Cane Creek's eeBrake.

In direct mount? Yes. I wouldn't go much beyond 28 with standard mount ee's though.

[robt57]

Better tire clearance. If you want tire clearance on short reach calipers, direct mount is the way to go.

Can't agree. I only have experience with one set direct mounts. On a 2018 Domane RSL bike I came close to purchasing. It was Di2 DuraAce Direct mount.

I already had a Endurance Series 6 it would replace which a 28mm rear and a 31mm front [measured on 622x19c rims] fit, albeit a tad tight front. The purchase impetus was longer and lower bike [Endurance geom too short and stack too much for me] which could fit bigger tires. Or at least same size a little bigger front and rear.

At the LBS, we tried 28s and 32s off other bikes in the store. 32mm total no go. On the front 28mm was so close to the casting protrusions on the caliper's 'direct' bolts I would not run those personally. So front smaller tire than the Endurance I was selling off. I left without the bike.

I now have a Team Issue 2013 Leopard/Radioshack Domane that fits 30.5-31mm tires [measured] with fair to good clearance front and back with single bolt Dura Ace calipers. A 32mm just touches, the one I tried anyway. I want to see 4-5mm of breathing room. Just looking at the bike from the side the pad carriers front and back are almost all the way down in the adjustment slots in the calipers.

I use 28mm Grand Prix which are almost 31mm inflated summer, currently sporting Ritchey Alpine WCS/JB 30mm. The JB inflated are a tad smaller than the Conti 28 which swell a touch more inflated I have found. 75-80 f/r psi FWIW.

Sorry for all the words, I am not good at making long stories any shorter. ;)

The direct mounts did have more room at the top of the tire, but a 622x19-21C rim is going to fatten the tire right at the direct pivots mount axis points. It was too close for comfort for me. So a 17c rim might bulb the top of a tire and not sit as wide, but kind of defeats some purposes to wide rims I am not willing to give up personally.

[simonov]

I think they're worth it if it's already part of how the frame is designed and built. Given a choice, I'd pick direct mounts every time. But most custom builders aren't offering them so I wouldn't base my decision on what builder to go with based on the brake options. But if the builder offers them, I'd say to go for it.

[peanutgallery]

Lots of effort for marginal improvement in tire clearance and braking. Most companies and builders will just bypass and go straight to disc. The new roubaix will fit a 32 with ease, tarmac disc is close behind

[oldpotatoe]

BACK to the Future:)

[R3awak3n]

I like DM brakes, its too bad they came a little too late and now a lot are on disc brakes. If I was to do a custom I probably would go DM. And go EE brakes. I think there is no reason to now if you can get the brakes you want as DM. Maybe will be harder to come across spare brakes in the long future but who cares. I think they look cool, better clearance, maybe stiffer?

[ERK55]

At the Philly Bike Expo I had asked the builder of the frame pictured earlier in this thread re the option of direct mount brakes. Apparently there is a lot more work involved, particularly on the fork end. This apparently depends on the fork crown chosen as some will require placement of the studs on part of the crown itself (this not the case with a Max fork crown). While he did not quote a number there was the implication that this option was pricey.

[Tony]

I like DM brakes, its too bad they came a little too late and now a lot are on disc brakes. If I was to do a custom I probably would go DM. And go EE brakes. I think there is no reason to now if you can get the brakes you want as DM. Maybe will be harder to come across spare brakes in the long future but who cares. I think they look cool, better clearance, maybe stiffer?

Agree, a step up from single mount.

[Mark McM]

Direct mount brakes are totally unnecessary. There is no reason for them to exist. They don't do anything better than conventional brakes. Nor do they do it worse. Except if you are a rider who rusts things, they become harder to adjust than conventional caliper brakes. There is not a wide range of models available and with the intrusion of disc brakes, getting parts or replacements for them in the future might be a problem.

If this argument were true, then why did sidepull brakes replace centerpull brakes? They all do the same thing, right?

Compared to conventional dual pivot brakes, direct mount brakes are:

Lighter
Stiffer
Higher leverage
Stay centered better

Direct mount brakes may not be a revolutionary departure, but they are certainly an evolutionary step (in the right direction).

[Mark McM]

Better tire clearance. If you want tire clearance on short reach calipers, direct mount is the way to go.

Tire clearance is more about the frame than the brake calipers. If the brake mounting hole is too low, then there will be little tire clearance regardless of the brake calipers. Raising the mounting hole will increase tire clearance, and then you just need a caliper with a longer reach.

Direct mount brakes require standardized mounting positions, which gives frame designers less leeway in building in tire clearance. Current direct mount standards allow tires up to about 30mm. This is more clearance than many standard rim brake frames of the recent past - But many riders are looking to use tires bigger than 30mm, which is can't be accommodated by direct mount brakes. However, tires wider than 30mm can be accommodated with medium and long reach standard rim brakes.

[Mark McM]

Also, though I can't prove it, my DM brakes seems to have more power than traditional mounted Rev+ era Campy brakes. There's no obvious downside, so why not?

Indeed they do. One of the factors affecting the leverage ratio of dual-pivot brakes is the distance between the pivots. Direct mount brakes have a wider distance between pivots, and therefore a higher leverage ratio.

Typical leverage ratios of caliper brakes:

Single pivot: ~1:1
Center mount dual pivot: ~1.6:1
Direct mount: ~2:1

[saab2000]

Modern brakes have way more tire clearance than older ones, at least in the “modern” era.

My reason for wanting direct mount brakes is very shallow - they look really cool!

[prototoast]

My only knock against direct mount brakes is that (at least for Shimano's design) they seem to collect more debris, which is harder to remove compared to regular brakes.

[Mark McM]

BACK to the Future:)

U-brakes have similar pivot/mounting bolt positions to Direct Mount brakes, but they have very different actuation mechanisms, and different cable routings. Direct mount brakes are far closer to standard dual pivot brakes then they are to U-brakes (or centerpulls or cantilevers).

[GScot]

Just for the record I'll add that I have a 2018 Domane with Bontrager direct mount brakes. 30mm tires on RS81s that have a 20.8mm rim width. The release toggle allows the tires to just clear the pads going in and out fully inflated. With 32s there is plenty of clearance when installed but you need to open the cable adjuster a couple of turns to swap an inflated tire. To be complete in this description the rims I used with 32s are about 23 wide.

[sg8357]

I have brazed on Paul Racers aka direct mount brakes,
they're very nice. Pic of Compass aka MAFAC DM Racers.
Note that you lose the patented pedestrian warning squeal
when you direct mount them.

[zzy]

I'm actually disappointed that OEMs didn't use DM brakes as a chance to move to mid-reach brakes with 35/40mm of tire clearance. The pivot mounts give excellent mechanical leverage so the added arm length shouldn't be a big factor. Short reach DM's don't make a ton of sense to me when modern center mounts work so well. A compelling upgrade would be disc-brake tire clearance with the ease of use of conventional brakes.

[robertbb]

Too many variables here...

the most important variable being what you're comparing the DM brakes to. The braking modulation and power of the "traditional" dual pivot brakes is varied depending on the model. Shimano's ones I've found to be grabby and just feel very binary... while, Campy Potenza skeleton brakes outperform their C/R/SR counterparts. Best rim braking I've ever experienced on those Potenza skeletons, including on DM brakes, and they also support 30mm tyres easily (as long as the frame does).

Pad selection makes a huge difference too. It's a system.

[saab2000]

Too many variables here...

the most important variable being what you're comparing the DM brakes to. The braking modulation and power of the "traditional" dual pivot brakes is varied depending on the model. Shimano's ones I've found to be grabby and just feel very binary... while, Campy Potenza skeleton brakes outperform their C/R/SR counterparts. Best rim braking I've ever experienced on those Potenza skeletons, including on DM brakes, and they also support 30mm tyres easily (as long as the frame does).

Pad selection makes a huge difference too. It's a system.

Best brakes I’ve ever had were the original Campagnolo dual pivots from the early/mid-1990s. Powerful and progressive in their modulation.

Next best are Dura Ace 9000s and they’re close.

I do like the DM concept and the aesthetic of that design.

[Cbh]

I live in he Dallas area too and have direct mount brakes on my road bike. They are fine for me but they don't seem noticably better than my previous rim brakes. They came on my colnago but I don't think I'd pay a premium for them.

[nortx-Dave]

Dumb question maybe....but are direct mount brakes compatible with carbon forks??

[xtheendisnearx]

mehh, I think direct mount brakes are just trendy. But then again, I would have not thought 10 years ago that road bikes would have thru axles with disc brakes.

[prototoast]

Dumb question maybe....but are direct mount brakes compatible with carbon forks??

Yes. Direct mount brakes are most commonly found on carbon forks, from manufacturers such as Trek and Canyon. To my knowledge, no one makes an aftermarket fork for direct mount brakes.

[Mark McM]

I have brazed on Paul Racers aka direct mount brakes,

The term 'Direct Mount' usually refers to a type of dual pivot sidepull caliper in which he pivots mount directly to the frame. These are very different from the Paul's brakes, which are a type of 'Centerpull' brake. Like other dual pivot caliper brakes, Direct Mount Dual Pivot brakes are actually a linkage mechanism brake, which magnifies their leverage (about twice that of a centerpull brake). The dual pivot linkage mechanism also guarantees that the brake arms remain centered (which is why dual pivot brakes only require only a single return spring). A Centerpull brake is quite rudimentary compared to a Direct Mount Dual Pivot brake.