Steep hill -- short hard braking or drag the brakes

[Doug Stampfer]

This is a good video. Bens' videos seem to focus on the way to get down a hill fast which is good if that is your aim however in this context it points out the difference between comfort braking & race braking. The latter is good when faced with a tricky section.

 

[RickBullotta]

Sounds interesting but $1600 for sensors to learn how to brake better sounds a little steep ! I would give it a try but in general, I just want to ride safely and crash less. challenge myself and enjoy riding my bike. I am not out to win any races.

Ha - I wasn't suggesting buying them. He sells to coaches. My point was that there has been a lot of studying how braking impacts performance.

 

[Slapbassmunky]

Get a larger diameter and thicker front rotor as 70% of the braking is done in the front. I have cooked enough rear rotors using Shimano IceTech with metalic compound pads that I know it doesnt help to drag your rear brake. When it gets real steep, we tend to lock up the rear wheel and surf down (keep the front wheel rotating!). This of course only works on loose loam and would be suicide on rock slabs as your rear wheel slips out .

People generally 'size down' on the back brake, which is madness to me. Join any uplift line and have a cursory look at people's rotors. 9/10 it's the rear one that's got evidence of heat issues. Personally I wouldn't touch ice tech, been there done that, the best I've found so far are MDR-P used with EBC sintered pads. Again, I've tried the cheaper wonder compounds available from every man and his dog and always gone back to proper quality sintered.

Brakes are a funny thing, you need them to be able to cope with the 1% of riding you do or else you'll be in real trouble, everything else on a bike you select to cope with 90% of what you do. It also means I end up riding cycle tow paths with MT 7's and 220 rotors

 

[skinipenem]

I think you're both right. Intermittent braking allows for cooling periods resulting in a peak temperature closer to the average thereby avoiding boiling and brake fade. I could be wrong.

Same area under the curve for temperature vs time.

 

[Pdoz]

Meanwhile, the physics nerd in the corner mumbles " terminal velocity" whilst the lawyer and ambulance driver chuckle. The engineer scrunches up the napkin with scribbled down formulas, and the waitress wanders over to refill Garys pint. Where is Gary nowadays?

 

[DogRanger]

Just like to add one comment: We should all be considering potential trail damage, particularly when in multi-use areas. I always try to avoid locking up brakes as much as conditions and my skills allow because that will reduce the likelihood of MTBs (and especially eMTBs) being banned from many trails. Preserve your brakes, yes, but also preserve the sport.

This may be less applicable in bike parks and downhill racing, but nearly all my rides are on trails shared with hikers and equestrians.

 

[1oldfart]

There are 99 good answers.
It depends on the surface, on the tyres, etc...
Just stay in control and you might modulate front/rear

 

[Stihldog]

Here’s another conundrum; Four of us each have a 2020 Rail (2-Rail 9.7 and 2-Rail 7). We all have Magura Mt7’s with 220mm rotors f/r and use Magura “performance” pads. We all ride the same mountain (Burke Mountian) but on slightly different trails. Elevations are very similar to each other but our riding styles differ.
I’ll call us Mark, Sean, Anthony and Drew. (Neighbour’s we are).
Mark goes through the most pads. Sean uses the most Royal Blood. Anthony uses pads and Royal Blood equally when compared to Mark and Sean. Drew is all over the map, and he hits Whistler more than any of us.
Mark rides daily and adds a lot of kms and elevation.(4x). Sean is KOM on several trails. Anthony services his bike after every single ride. Drew is still all over the map. We all break things constantly. (Including bones).
I’ve installed the brakes on all these bikes yet I cannot figure out why (I stopped trying) our brakes are all different. It’s a mystery .

 

[emtbPhil]

The reason you stamp on the brakes before a corner in a race car is 100% to do with heat and nothing to do with engine braking.
The flywheels are so light in those cars you barely get any engine braking.

If you ever drag your rear brake lightly down an entire long downhill section you'll soon find out that heat kills brakes pretty quickly, and can boil fluid.

That being said on a MTB you just need to stay in control of the bike, no point slamming on at 35mph at the bottom of a descent, locking up or going over the bars.
I agree with the philosophy of feathering the rear brake to keep the speed under control and using the front if you need to scrub speed fast. Don't forget when you brake your weight shifts forward which is why most cars/bikes etc.. have like a 70/30 brake bias towards the front. The rear wheels just don't have the weight on them so lock up.

 

[maker]

Energy absorbed by brakes is same potential energy in both cases. However if speed climbs before breaking the descent is shorter time so energy absorbed in less time, so brake reaches a higher temperature albeit for a shorter time. Generally degradation depends exponentially on temperature and linearly on time which suggests constant braking is kinder to longevity, but boring. e.g. you'll feel worse if you are 1,000C for 1s and 20C for 99s rather than the average (1000*1+20*99)/100 = 29.8C for 100s

 

[emtbPhil]

Energy absorbed by brakes is same potential energy in both cases. However if speed climbs before breaking the descent is shorter time so energy absorbed in less time, so brake reaches a higher temperature albeit for a shorter time. Generally degradation depends exponentially on temperature and linearly on time which suggests constant braking is kinder to longevity, but boring. e.g. you'll feel worse if you are 1,000C for 1s and 20C for 99s rather than the average (1000*1+20*99)/100 = 29.8C for 100s

Except you’re completely ignoring heat dissapation.
Go slam on the brakes for a few seconds and check the heat. Then trail brake the whole way down and wonder why your brake rotors are blue

 

[Akiwi]

Very interesting discussion.
When on Tarmac, I tend to go as fast as possible. If I want to go faster, I lower the seat to reduce drag. When coming to corners / obstacles, I stand up and brake hard. If I want to go slower, stay standing to increase wind resistance.
On the other hand, when on firm Gravel (not loose gravel) where I know I can't brake hard before a corner, I tend to control my speed by alternately pumping with the front and rear brakes with periods where both are off for cool down, and use both, mainly the front when I need to brake hard. (I guess this is what the discussion is about).
Yesterday I did a big tour in Austria to 2200m and there was a long tight gravel trail followed by a long steep loose gravel road back down. So steep and loose that I lost traction several times on the way up. There I just concentrated on controlling my speed with using both brakes. Look ahead, anticipate the terrain. Let off when it is smoother and you can see a clear area to brake before the next obstacle.
I enjoyed my new 220 Magura floating disk in the front wheel for my MT7 brakes. It definitely coped very well.

 

[Daev]

I prefer to keep my rotors nice and straight so use the brake, let go, brake, let go method mostly. Not saying that I wont drag them occasionally, but always drag both front and rear to be more balanced. Occasionally on some really steep, scary transition roads, the build of the road means speeds increase super fast and the corners are sketchy so I will drag front brake then rear brake - alternating between them to keep speed down, but also to allow some cooling to stop totally screwing up my rotors.
Where I ride, I regularly ride in excess of 50kph on the trails I ride and in some events I used to do had been over 100pkh on smooth gravel or sealed sections. I probably replace pads every couple months so always have some spares and some good second hand pads in my kit, but really hate replacing rotors too often as $100 each end makes that an expensive proposition. I also use resin pads to give me the feel and control I want as well as being kinder on the rotors.

Oh yer - I'm also 108kg so carry a lot of momentum on the downs.

 

[Daev]

Bit of both, as and when necessary.
I like to stay alive and intact. I constantly make the judgement as to what is required.
I used to find this with snowboarding. There were idiots out there who would just let it all go and hope to finish the run alive, without having killed anyone else - obviously out of control but having a good time.
I knew i could stop at any time and was therefore always in control.
It's a matter of using the tools available to ensure well-being.

 

[Daev]

im 67.5kg i used to be a fat blob and 38inc for shorts im now down to 34inc so at 120 rpm that is what you call keeping fit bar my hips falling to bits

I dropped from 15 to 11 stone last year by cutting out biscuits cakes and chocolate. My wife complained i was starting to look a bit ill so i hit the carbs. Back up to 12st. Wishing i'd stayed at 11 - i felt great

 

[Daev]

You are not all riding together always???
or, Some of y’all fat asses. Some of y’all scared stiff and always breaking. Some of y’all buy cheap pads. And some of y’all don’t center disk on rotor and press pistons in equally and have a slight constant drag

I assume you’re joking tho….

I got lost in the middle somewhere....i was expecting a hen, a fox, a sack of corn and a river to turn up

 

[maker]

Except you’re completely ignoring heat dissapation.
Go slam on the brakes for a few seconds and check the heat. Then trail brake the whole way down and wonder why your brake rotors are blue

You brake for lots of few seconds if the alternative is braking all the way down.

 

[maker]

Except you’re completely ignoring heat dissapation.
Go slam on the brakes for a few seconds and check the heat. Then trail brake the whole way down and wonder why your brake rotors are blue

Yep, ignored quite a few factors, just pointing out one. If you need to brake all the way down you would need more than one brake for a few seconds.