140 front disc rotor

Discuss light weight issues concerning road bikes & parts.
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mpulsiv
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by mpulsiv

AJS914 wrote:I have 140s front and rear on my Crux and it seems to stop better than my Colnago with rim brakes.


What calipers on your Colnago?
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AJS914
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by AJS914

Chorus calipers with stock Campagnolo pads + Eurus wheels.

by Weenie


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ms6073
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by ms6073

wheelbuilder wrote:No. Those flat mount brakes on your Scott require that mounting wedge to function. Can't mount them otherwise.

Maybe I misunderstand, but the Scott Addict/Solace only require the riser on the rear caliper in order to run 160 mm brake rotors, and has separate mounting bolts that bolt into the caliper from underneath the adapter versus, the flat mount bolts which are inserted from underneath the stays. The adapter is easily removed as the wife and I run the new DA BR-R9150 brake calipers and 140 mm rotors front and rear on 2017 Scott Contessa Solace and 2016 Scott Solace!
Michael - The Anaerobic Threshold is neither...

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wheelbuilder
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by wheelbuilder

ms6073 wrote:
wheelbuilder wrote:No. Those flat mount brakes on your Scott require that mounting wedge to function. Can't mount them otherwise.

Maybe I misunderstand, but the Scott Addict/Solace only require the riser on the rear caliper in order to run 160 mm brake rotors, and has separate mounting bolts that bolt into the caliper from underneath the adapter versus, the flat mount bolts which are inserted from underneath the stays. The adapter is easily removed as the wife and I run the new DA BR-R9150 brake calipers and 140 mm rotors front and rear on 2017 Scott Contessa Solace and 2016 Scott Solace!

You are absolutely right. I am the one who was misunderstanding this whole topic! 140 on rear is totally do-able. 140 on front can be harder to find forks that will allow this. Are there even forks out there that will run flat mount 140mm?

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ms6073
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by ms6073

Yes. All disc forks that employ the Shimano flat mount standard can be setup for 140 mm brake rotors. For Shimano flat mount front caliper, just need to flip the adaptor as the 'stock' out of the box setup is for 160 mm rotors, but simply flip the wedge and you will be set for 140 mm rotors.
Michael - The Anaerobic Threshold is neither...

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spookyload
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by spookyload

Lynskey’s procross fork is 140mm standard. Great fork too.

Cemicar
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by Cemicar

Some forks are actually 160mm only. BMC's Teammachine SLR01, for instance.

simplemind
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Joined: Mon May 04, 2015 11:06 pm

by simplemind

I have 140 Shimano Ice Tec f/r on both my Parlee Chebacco and my Synapse. I'm 165 riding weight and have no issues in the mountains or in the rolling hills. Plenty of stopping power. My driveway is the best test, which has some 18% -20% grade sections where I have to feather the brakes to keep them from locking up. That's more than enough stopping power.
One point is with my all mountain bike, there is much more rolling weight due to the heavier tires and rims, plus hydration pack, etc, maybe 175-180 riding weight plus 10 lbs heavier bike, so I'm running 180/160 rotors and quite happy with the stopping power and modulation.

uraz
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by uraz

I'd say that far better test is to stop your bike as fast as possible from 60-90 km/h, 20 times in a row (series of switchback in high mountains).

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ergott
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by ergott

Cemicar wrote:Some forks are actually 160mm only. BMC's Teammachine SLR01, for instance.


Another is Whiskey No. 7 quick release disc fork is 160mm without any adapters.

joejack951
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Location: Wilmington, DE

by joejack951

uraz wrote:I can't get even close to locking front wheel with road hydraulic brakes which is a shame in my opinion. There is a ton of grip on soft, slick tires when road is dry and clean (most typical conditions), way more than on mtb (damp forest, sand, loose rocks, etc).

Only reason I see, why road brakes are so pathetic is that some guys (and girls) don't want or can't handle brakes that are able to throw them out of a bike. Also very strong brakes could be problematic in rain.


This sentiment sounds contrary to most I've read about road disc brakes, and certainly doesn't agree with my own personal experience, albeit only with mechanical (Avid BB7) and hybrid mechanical (TRP HY/RD) disc brakes. It sure sounds like something is off with the brakes on the bikes you've ridden if you feel like there is no chance of locking the front wheel.

This past Friday I went out on my bike with the front-only BB7 disc brake and had no trouble stopping on some slight inclines even with a ~55 kg. trailer load attached to the bike (Burley trailer plus two kids plus a bike and misc. kid stuff). I have a 160mm rotor on that bike.

For using a 140mm rotor up front, for someone on the lighter side, I'd say go for it. My full-disc road bike with the HY/RD calipers has 160 front/140 rear rotors and even using just the rear provides surprising stopping power. If I was going full weight weenie on that build I'd have gone with 140mm front no question. As it were, I wasn't all that focused on lightweight and I was ~15 kg. heavier when I built it, too. Down to 67 kg. now and the 160mm front has gone from more than adequate to serious overkill.

uraz
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by uraz

joejack951 wrote:This past Friday I went out on my bike with the front-only BB7 disc brake and had no trouble stopping on some slight inclines even with a ~55 kg. trailer load attached to the bike (Burley trailer plus two kids plus a bike and misc. kid stuff). I have a 160mm rotor on that bike.


Don't get me wrong but "I have no trouble stopping" can be assotiated with cantilever brakes, u-brakes, road hydraulic, 2 piston xc brakes or 4 piston downhill brakes. Does it mean that they all have equal power and fell?

I'd say that road hydraulics are not stronger than dura-ace on aluminum rim on sunny day. At the other hand I know that hydraulic brakes in general, can be 10 times better than mentioned dura-ace, because I also have them on MTB.

joejack951
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by joejack951

uraz wrote:Don't get me wrong but "I have no trouble stopping" can be assotiated with cantilever brakes, u-brakes, road hydraulic, 2 piston xc brakes or 4 piston downhill brakes. Does it mean that they all have equal power and fell?


My point was that road disc brakes aren't inherently weak as you've proposed. My riding weight plus that loaded trailer was ~120 kg. And I was stopping fine (no death grip on the lever required) with just the front BB7 brake on a 160mm rotor.

uraz wrote:I'd say that road hydraulics are not stronger than dura-ace on aluminum rim on sunny day. At the other hand I know that hydraulic brakes in general, can be 10 times better than mentioned dura-ace, because I also have them on MTB.


The two road-lever actuated disc brake bikes I have brake far better than really good rim brakes on aluminum rims that I have for comparison (Dura Ace 7800, Ultegra 6600, and 105 5800 calipers on machined aluminum brake tracks). The TRP HY/RD equipped bike has substantially more powerful brakes than the BB7 bike, too. So much so that the BB7 caliper is soon going to be replaced with another HY/RD.

uraz
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Joined: Thu Dec 12, 2013 9:48 pm

by uraz

You are right, road disc brakes are not weak like for example u-brake on wet carbon clincher rim but they are not as strong as they could be.

Of course in normal day-to-day use I don't have to pull levers with unhumane force, they perform well (on pair with best conventional brakes setup or slightly better), but when I want/need all the braking power that my tires can handle, sram red hydroR can't deliver it. I had high hopes for road hydraulics and maybe this is a reason I'm not so satisfied with them. I like brakes that can generate force bigger than I would ever want to use. Front wheel locking point at 80% of total capability (something like shimano xt), not at 120%.

PS> I would be totally satisfied with 40% greater maximum power. Supposedly new sram hydroHC are stronger.
Last edited by uraz on Tue Nov 07, 2017 12:00 am, edited 1 time in total.

bm0p700f
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by bm0p700f

i dont want to lock my front wheel up though. Even on a emergancy stop I dont lock the front up and I come to a very rapid halt. I like it that way. why would I need a brake which can lock my front wheel and get the rear of the bike to ride up. I would have to put more weight in the panniers, oh wait thats why I dont get front lock.

by Weenie


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