Direct mount brakes, better, worse?

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martinn
Posts: 365
Joined: 1 Dec 2012, 8:20pm

Direct mount brakes, better, worse?

Postby martinn » 1 Jul 2020, 7:40pm

Hi all

sorry full of questions.

I am looking to replace my current frame that I ride fixed with a purpose built frame designed for fixed.
currently as I want to run mudguards and a 25mm Tyre minimum, that is good valve for money, I have sort of ended up with the Spa Mono or the Dolan FXE. Steel vs Aluminium, both have a carbon fork, both max of 28mm tyres, but I was just going to get the frame and forks and transfer the rest of my gear over.
But the Spa has been out of stock for a while, and is not expected to be back in stock for at least another month, possibly more.
The Dolan on the other hand, has direct mount brakes, and i would need to purchase a set of these if this is the route I choose. Aslo have to think how to mount my front dynamo light

Ramble over, is there much difference between the Direct mount and normal rim brakes? both would be mounted in the conventional position.
it it worth the extra cost?

thanks

Martin

peetee
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Location: Cornwall

Re: Direct mount brakes, better, worse?

Postby peetee » 1 Jul 2020, 7:46pm

A friend has Ultegra direct mount with 25c tyres. To my eye 28c might be too wide.
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martinn
Posts: 365
Joined: 1 Dec 2012, 8:20pm

Re: Direct mount brakes, better, worse?

Postby martinn » 1 Jul 2020, 8:00pm

Really confusing, went back to the Dolan site,
It does say that it fits a Direct mount rim brake, and for the frame set now says 23-25mm

However on the FAQs it says maximum tyre size 28mm.
I think it would be 25mm max with mudguards, but wonder if they have just changed to direct mount brakes, as the images seem to show the bike with a traditional crown mounted brake

I looked at the spec on the Direct mounts, and they do say up to 28mm tyres

Martin

slowster
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Joined: 7 Jul 2017, 10:37am

Re: Direct mount brakes, better, worse?

Postby slowster » 1 Jul 2020, 8:32pm

According to the website, the Dolan FXE takes conventional caliper rim brakes like the Spa, e.g. as per this build.

That said, it looks to me like there are quite a lot of differences between the two frames/bikes - so much so that personally I would not think of one being an acceptable alternative to the other. I suspect that if you had the chance to test ride both bikes you would be likely to strongly prefer one of them.

Spa provide no geometry information for the Audax Mono, but I presume it is simply the same geometry and tubing as the geared Audax, but with a 120mm rear spacing. Similarly Dolan provide incomplete geometry for the FXE. Neverthless, it looks like the FXE will have quite different handling: the chainstays look to be much shorter once the difference in seat angles is taken into account (75 vs 72.5 degrees) and the head angle is steeper (73 vs 72 degrees).

Dolan say that up to 25mm tyres can be fitted with mudguards, vs 28mm for Spa's Audax. That difference will be determined not by the brakes (both are designed for 47mm-57mm 'deep'/medium drop calipers), but by the specification, precision and accuracy of the frame design and construction. In other words, the chainstay bridge of the Spa will be positioned to put the brake pads close to the bottom of the slots, to maximise tyre/mudguard clearance, and Spa have evidently chosen a carbon fork with similar clearance.

Dolan emphasise the frame's stiffness and seem to have designed it with the urban fixed rider as the target customer ("In a frame designed with an oversized downtube, it provides those sought-after characteristics of any urban bike, both low weight and stiffness"), whereas I presume that the Spa's ride quality will reflect the fact that the origin of the frame was based on long distance audax riding.

Cyril Haearn
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Re: Direct mount brakes, better, worse?

Postby Cyril Haearn » 1 Jul 2020, 8:37pm

I think you should find out a lot more before ordering, it is unclear exactly what tyres/mudguards fit
I should not order a frame without seeing and measuring it
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Oceanic
Posts: 96
Joined: 24 Sep 2010, 7:21pm

Re: Direct mount brakes, better, worse?

Postby Oceanic » 2 Jul 2020, 8:39am

To answer the original question...

I found a small, but noticeable difference in stopping power when I swapped from a frame with SRAM Force rim brakes to SRAM S Series direct mount rim brakes.

My bike has no mudguard mounts, but I would be surprised if you could fit any more than 23c tyres inside the SRAM direct mount calipers when using mudguards.

Brucey
Posts: 41357
Joined: 4 Jan 2012, 6:25pm

Re: Direct mount brakes, better, worse?

Postby Brucey » 2 Jul 2020, 9:05am

this picture

Image
2019 FXE

shows a 23mm gatorskin. If the current model is similar I'd say you would be able to squeeze 25mm and a mudguard in there.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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Oceanic
Posts: 96
Joined: 24 Sep 2010, 7:21pm

Re: Direct mount brakes, better, worse?

Postby Oceanic » 2 Jul 2020, 9:29am

25c Tyres (which measure 24mm) inside SRAM direct mount brakes. Seems that there is more room than I remembered.
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Marcus Aurelius
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Joined: 1 Feb 2018, 10:20am

Re: Direct mount brakes, better, worse?

Postby Marcus Aurelius » 2 Jul 2020, 9:37am

I’ve got stay mounted direct mounted rim brakes and 25mm tyres, on one of my bikes. I prefer them to the pivots on a couple of other bikes. They give better feel, and are more controllable. They are a bit of a pain in the bum to adjust / trim, ( especially after a wheel out puncture repair ) and recable, relative to the pivot mounted ones, but worth the extra hassle.

martinn
Posts: 365
Joined: 1 Dec 2012, 8:20pm

Re: Direct mount brakes, better, worse?

Postby martinn » 3 Jul 2020, 9:02pm

thanks for the replies.
so generally a little better overall, but possibly more of a faff to set up

Martin

fastpedaller
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Location: Norfolk

Re: Direct mount brakes, better, worse?

Postby fastpedaller » 3 Jul 2020, 9:13pm

I'd never heard of direct mount brakes until this thread - I had to do a web search to get more details :shock: Amazing how the manufacturers keep thinking up 'new' products.

Brucey
Posts: 41357
Joined: 4 Jan 2012, 6:25pm

Re: Direct mount brakes, better, worse?

Postby Brucey » 3 Jul 2020, 9:25pm

fastpedaller wrote:I'd never heard of direct mount brakes until this thread - I had to do a web search to get more details :shock: Amazing how the manufacturers keep thinking up 'new' products.


Image

yes although (like many 'new' ideas) this is arguably an old idea that has been warmed over.

Image
Mafac centre pull bosses

Image
Braze-on centre pull brake

Decades ago folk realised that centre-pull brakes (eg Mafacs) worked better if the arms were fitted to bosses that braze on to the frame, because the usual backing plates are always a bit flexy. The main difference between shimanos direct mount and ancient mafacs etc is

a) the look of the thing and
b) the way the arms work and move together to 'average out' the MA which would otherwise be different side to side in the shimano brake (a bit like a DP is, although in this case the arms at least pivot about similar mounts.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Direct mount brakes, better, worse?

Postby Brucey » 3 Jul 2020, 9:35pm

using my 'crystal ball' I predict that if 'direct mount' flourishes then we will see more rim brakes with hydraulic actuation again. Two bosses set like that is an ideal arrangement to have a 'pusher' set between them, high up; ideal for a small hydraulic slave cylinder.

Sram are almost there already

Image

Image
"hydraulic master cylinders? Nothing in the slightest wrong with the way they look."

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

scottg
Posts: 843
Joined: 10 Jan 2008, 8:44pm
Location: Highland Heights Kentucky,, USA

Re: Direct mount brakes, better, worse?

Postby scottg » 4 Jul 2020, 1:23am

fastpedaller wrote:I'd never heard of direct mount brakes until this thread - I had to do a web search to get more details :shock: Amazing how the manufacturers keep thinking up 'new' products.



People have been direct mounting MAFAC Racers since the 1950s. In 2004? Paul Components started making a MAFAC like
brake, direct mount only. Since then centres of French bike building in Japan and the USA have been building bikes for direct
mount brakes. The unearthly shriek of a MAFAC or MAFAC like brake will clear a path like no bell can. :)
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Deutsche Luftschiffahrts-AG
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