Riders on disc brakes. How often do you lock up your rear wheel?

Discuss light weight issues concerning road bikes & parts.
Delorre
Posts: 966
Joined: Sat May 24, 2014 12:09 pm

by Delorre

Happens from time to time, but that's only when braking very hard at front causing massive weight transfert to the front. In such occasions, the rear wheels almost floats above the tarmac, and locking the rear becomes very, very easy and it sometimes happens without intention to do so. But as said, modulation is so good, that it's easy to control. Have to admid, I tend to brake very late and hard just for the fun of it 8)

by Weenie


ODC
Posts: 138
Joined: Mon Aug 14, 2017 9:40 am

by ODC

On my MTB sometimes
On my roadbike at this moment never

LiquidCooled
Posts: 81
Joined: Mon Oct 02, 2017 5:46 am

by LiquidCooled

Once, when my bike was new (and I was new to disc brakes), I locked them up in a panic stop to avoid a car. Since then, never. I've locked up rim brakes many more times (admittedly, I've ridden rim brakes way more in my life).

Last week, I rented a bike (rim brakes) while out of town. I joined a group ride and nearly rear ended someone because I was no longer used to the heavier effort needed with rim brakes. While I quickly did the mental adjustment, the rest of the ride reminded me how much better the modulation is with discs (imo).
2017 Giant TCR Advanced Pro 0 Disc
2003 Cannondale R1000 (CAAD7)

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zank
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Location: Sutton, MA USA
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by zank

Never.

robertbb
Posts: 550
Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

It's due to locking of the rear wheel (and weight advantage) that I still run single pivot rear brakes (campy) on two of my bikes. I can count a few times where the lack of power in the rear brake has saved the back-end from sliding out from underneath me on a spirited descent (or panic situation).

Look at any sports car, motorbike... the front brake is always more powerful than the rear - for good reason. 70/30 rule.

Campy's differential braking option was actually smart, and they never should have discontinued them. But they seem to be making a lot of stupid decisions lately.

</rant>
It's ALL about the bike.

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silvalis
Posts: 472
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

Never, excluding emergency stops and skids for the fun of it.
Chasse patate

JapanStan
Posts: 18
Joined: Mon May 28, 2018 5:03 am

by JapanStan

First time yesterday, after 7000km... And that was due to rider error as i panicked when an old 'Dear' pulled out on me in her metal box

martinkartin
Posts: 11
Joined: Thu Jul 06, 2017 5:21 am

by martinkartin

Surprisingly I have only ever locked my rear brakes once and that was when I was trying to stop after losing balance riding too close to the gutter. I've made a lot of heavy braking on my road disc bike but so far never hard enough to lock at all.
Factor O2 Disc Romain Bardet Limited Edition

jlok
Posts: 713
Joined: Tue Jun 30, 2015 3:30 am

by jlok

Got my new Propel Adv SL Disc size M and locked the rear once within the first 100km. My previous bike was TCR ADV SL Disc size S with eTap HRD and 160mm rotor. The lock up on my Propel Disc was probably a learning process of CoG and the brake lever feel, no big deal.
Giant Propel Advanced SL Disc 1 / BMC TM02 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

TobinHatesYou
Posts: 1887
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

jlok wrote:
Mon May 28, 2018 3:56 pm
Got my new Propel Adv SL Disc size M and locked the rear once within the first 100km. My previous bike was TCR ADV SL Disc size S with eTap HRD and 160mm rotor. The lock up on my Propel Disc was probably a learning process of CoG and the brake lever feel, no big deal.
Shimano hydro lever feel is definitely less progressive, not as spongy as SRAM. It feels much lighter until pad contact.

amngwlvs
Posts: 77
Joined: Fri Apr 20, 2018 2:45 pm

by amngwlvs

Been riding R8000 discs for a month now (1000km) and I haven't locked mine up yet. That said, I haven't hard to make any emergency stops where I needed to stop that quickly. Because of the increased modulation and brake feel I'd be more worried about locking up the rear on my rim brakes than the discs, which I definitely have done in a "holy crap, I'm coming into this switchback way too fast" moment.
2018 Giant TCR Advanced Pro 0 Disc
2015 Giant Propel Advanced 2
2013 Trek 520

jlok
Posts: 713
Joined: Tue Jun 30, 2015 3:30 am

by jlok

Yes Tobin, I'd love to have the brake lever feel of SRAM.
Giant Propel Advanced SL Disc 1 / BMC TM02 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

dcorn
Posts: 160
Joined: Thu Oct 05, 2017 4:21 pm
Location: NoVA

by dcorn

Delorre wrote:
Sun May 27, 2018 9:29 pm
Happens from time to time, but that's only when braking very hard at front causing massive weight transfert to the front. In such occasions, the rear wheels almost floats above the tarmac, and locking the rear becomes very, very easy and it sometimes happens without intention to do so. But as said, modulation is so good, that it's easy to control. Have to admid, I tend to brake very late and hard just for the fun of it 8)
I'd bet this is a big part of it. Better modulation of the front brake allows you to stop of the ragged edge of lifting the back wheel, even with body weight towards the rear. In a recent race of mine, there was a steep hill into a hard right onto gravel, meaning everyone was slamming on the brakes late to make the turn because any speed into the gravel had guys sliding into the woods on the outside of the bend. Every lap, I was carrying the rear wheel in the air at the height of braking force, meaning I wasn't technically skidding, but the rear wheel was def locked up.

jfranci3
Posts: 354
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

Shrike wrote:
Sat May 26, 2018 3:59 pm
Be honest.

Have a reason for asking and it's not to start a rim v DB flame war (again).
So there's three grades of braking
1) Not having the ability to 'lock them up' - under-powered braking.
2) You can lock them up, but not exactly when you want - No control.
3) You've got between 3 and infinite degrees of braking; grip, turning the wheel slower than the surface but not locked, and locked - modulation.

Disc brakes give you #3 because the pad is stiffer. If you don't have level 3, it's because you're rotor isn't properly sized or your pads suck/are inappropriate. Theoretically, a properly spec'd disc system will be outrageously better than a rubber pad/rim brake at slipping the tire and providing feedback. The problem is that disc brakes get contaminated easily, spokes are forgiving, road bike tires don't like slip, bike brakes are usually asked to work at room temp, and they need to engineer the system to work for normal inputs and rash, emergency inputs.
Rim brakes are at a disadvantage as they are rubber. There is a delay between your input and the action. What the pad is doing and what you feel has a longer time delay.

Properly spec'd disc brakes with a stiff pad, stiff caliper, and the right tire are AMAZING. Not a bike, but I had a track car with racing pads. I could intuitively summon 10 different levels of something between grip and lock. You can independently feel tire and brake action.


I'm 100% comfortable locking up brakes. I've only gotten #2 out of rim brakes. I've gotten 1,2, & 3 out of disc.

leicaman
Posts: 106
Joined: Fri Mar 14, 2014 3:55 pm

by leicaman

I ride SRAM red rim brakes on one bike (Enve 2.2 Carbon tubular rims) , Sram Rival Disc on the other. Never locked the rear wheel unintentionally on either bike. Plenty of skids on the disc bike but they were always done to put a smile on my face when descending;). I thought that switching between disc and rim brakes would take quite a bit of getting used to but they both feel like second nature to me.

by Weenie


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