Train descent skills

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BenCousins
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Joined: Thu Apr 23, 2015 11:46 am

by BenCousins

kik3sir wrote:
Tue Jun 18, 2024 12:04 pm
Hello,

I just participated in a ultra endurance event, I had good legs but I got dropped at every single descent, either I had to sprint to get back in the group, or I would ride solo for a while waiting for another group to catch me up.

In roundabouts i also lose so many positions as I'm scared to pedal when turning, i'm scared the pedal hits the ground and makes me crash.

I'm not a hot head, I don't want to start taking risks in training to develop this skill, but still I would like to improve, it's a shame to lose so many positions in a race + sprinting in descents where people are actually recovering.

I actually watch a lot of F1 and played a lot of F1 games, i'm familiar with picking the right trajectory but i'm just not confident in my GP 5000 having enough grip, I end up breaking when others don't at all

Do you have any tips to share ?
The key thing is that your tires have way way way more grip than you think. In Feb I followed Toms Skujiņš down the Amer descent near Girona. He was just taking it easy on the tops, rolling home from a power test on the climb, not pushing the descent at all. He was going 15kph faster than I thought the tires could handle. These things grip. Have had similar experiences folllowing Cyrus Monk down the Eze last summer.

usr
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by usr

twoangstroms wrote:
Tue Jun 18, 2024 4:49 pm
Closed roads or not is a big difference. The optimal or most comfortable line at your speed might not be within the lane.
Good advice! When the curve disappears behind your lane's side horizon, taking the opposite lane will result in less surprises from oncoming traffic than remaining in your lane. Just be careful to not cut into someone coming up from behind. An occasional check of what's behind me is one of the things that really make a difference in my descending confidence (which is at quite a low point these days, still dropping most average riders due to kg/cdA)

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jdms2k
Posts: 27
Joined: Thu Feb 08, 2024 1:21 am

by jdms2k

Super helpful thread as I'm working on my descending as well!

Additional tips for beginners:
- Finish all of your braking before the turn. Braking during a turn reduces tire grip because you're asking your tires to grip for the turn as well as grip to slow down. Also, do not brake with your rear brake unless you really know what you're doing. Otherwise, you can quickly lose rear wheel traction.
- Remember that people can do 40+ mph in the corners. Chances are, you're going way slower and therefore have a ton of tire grip available.
- Don't pedal in the corners. Push your outside shoe down hard in the corner and leave it there. When you get more confident, start pedal out of the corner as soon as you can.

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howaboutme
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by howaboutme

jdms2k wrote:
Tue Jun 18, 2024 9:11 pm
Super helpful thread as I'm working on my descending as well!

Additional tips for beginners:
- Finish all of your braking before the turn. Braking during a turn reduces tire grip because you're asking your tires to grip for the turn as well as grip to slow down. Also, do not brake with your rear brake unless you really know what you're doing. Otherwise, you can quickly lose rear wheel traction.
- Remember that people can do 40+ mph in the corners. Chances are, you're going way slower and therefore have a ton of tire grip available.
- Don't pedal in the corners. Push your outside shoe down hard in the corner and leave it there. When you get more confident, start pedal out of the corner as soon as you can.
Interesting. I have always assumed that you always use rear first and then front to enhance breaking (like coming to complete stop quickly). I think this is mostly assuming if you break hard using only the front, you'd lose control or topple over. The one caveat is when it's wet, I understand that.

MarkMcM
Posts: 187
Joined: Fri Mar 26, 2010 4:24 pm

by MarkMcM

howaboutme wrote:
Tue Jun 18, 2024 9:20 pm
jdms2k wrote:
Tue Jun 18, 2024 9:11 pm
Super helpful thread as I'm working on my descending as well!

Additional tips for beginners:
- Finish all of your braking before the turn. Braking during a turn reduces tire grip because you're asking your tires to grip for the turn as well as grip to slow down. Also, do not brake with your rear brake unless you really know what you're doing. Otherwise, you can quickly lose rear wheel traction.
- Remember that people can do 40+ mph in the corners. Chances are, you're going way slower and therefore have a ton of tire grip available.
- Don't pedal in the corners. Push your outside shoe down hard in the corner and leave it there. When you get more confident, start pedal out of the corner as soon as you can.
Interesting. I have always assumed that you always use rear first and then front to enhance breaking (like coming to complete stop quickly). I think this is mostly assuming if you break hard using only the front, you'd lose control or topple over. The one caveat is when it's wet, I understand that.
The thing to keep in mind is that the amount of traction a tire has is affected by how much weight is on it - tires with lots of weight have lots of traction, tires with little weight have little traction. Braking causes a forward weight shift - the harder you brake, the more weight will shift to the front wheel and the less weight there will be on the rear wheel. Due to this weight shift, the front tire gains traction and the rear tire loses traction when braking. That's why it is much easier to skid a rear tire under hard braking than to skid a front tire. So under the hardest braking, only the front brake should be used.

As you elude, if you brake too hard, there can be so much forward weight shift that the rear wheel can lift up, and the bike can start to go end-over-end. But it takes more braking than many assume to reach this point. In most cases when people "go over the handlebars", it isn't because the there was too much forward weight shift, it is usually because the rider failed to brace themselves with their arms. If a rider doesn't anticipate the forward weight shift and fails to brace themselves, they can find themselves flying over the handlebars before they even know it. How to prevent going over the bars or the rear tire lifting up? When preparing to brake hard, a rider should get their weight back and low, sometimes sliding the butt off the back of the saddle. Braking from the drops is not only more powerful than braking from the hoods, it is also more controllable. And the rider should brace themselves with their arms. In this position, the front brake can be applied very hard, but don't apply the brake at all once - ramp the braking force up to allow the forward weight shift to increase front wheel traction before applying full braking force.

mikehhhhhhh
Posts: 466
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Location: UK

by mikehhhhhhh

howaboutme wrote:
Tue Jun 18, 2024 9:20 pm
jdms2k wrote:
Tue Jun 18, 2024 9:11 pm
Super helpful thread as I'm working on my descending as well!

Additional tips for beginners:
- Finish all of your braking before the turn. Braking during a turn reduces tire grip because you're asking your tires to grip for the turn as well as grip to slow down. Also, do not brake with your rear brake unless you really know what you're doing. Otherwise, you can quickly lose rear wheel traction.
- Remember that people can do 40+ mph in the corners. Chances are, you're going way slower and therefore have a ton of tire grip available.
- Don't pedal in the corners. Push your outside shoe down hard in the corner and leave it there. When you get more confident, start pedal out of the corner as soon as you can.
Interesting. I have always assumed that you always use rear first and then front to enhance breaking (like coming to complete stop quickly). I think this is mostly assuming if you break hard using only the front, you'd lose control or topple over. The one caveat is when it's wet, I understand that.
It's quite hard to overwhelm the front brake.

I use the rear more to feel for grip, but it requires a fine touch - done right, you'll overwhelm the rear sooner with a little braking, often giving a little skip that allows you to get off the brake and correct, unlike the front sliding out.

My biggest tips would be;

Build up slowly - you've got to be comfortable, if you're stiff and rigid you'll crash.

Get your weight rearward as you brake, do it in a straight line, look at where you want to end up, so before turn in you're looking at the apex and once you're turned in you're looking at the exit.

Don't get too caught up about perfect lines, so long as you're doing a half decent job of using all the road available to you, the most speed will come from exploiting the available grip - hitting perfect apexes are a marginal gain from there.

Sometimes a high and wide line (effectively just following the contour of the corner, missing the traditional apex) with a higher minimum speed is less risky, as you achieve peak load more progressively than a traditional "racing line" that peaks around a sharper turn in.

Bonus tip for the wet - over slow and V the corner to minimise your time turning, another strategy that sacrifices a tiny bit of speed for a huge reduction in risk.

Get out on a mountain bike in the mud - get comfortable with handling a bike moving around underneath you at much lower speeds.

Try some sim racing to build up an understanding of the grip circle (this is the compromise between braking and cornering grip), braking, line choice, vision etc.

Fwiw, with just 2.5 years of road riding experience, I find myself faster than most at descending and cornering. I credit a lot of transferable skills from racing cars and some bike handling from riding mtb as a kid.

TobinHatesYou
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by TobinHatesYou

jdms2k wrote:
Tue Jun 18, 2024 9:11 pm
Super helpful thread as I'm working on my descending as well!

Additional tips for beginners:
- Finish all of your braking before the turn. Braking during a turn reduces tire grip because you're asking your tires to grip for the turn as well as grip to slow down. Also, do not brake with your rear brake unless you really know what you're doing. Otherwise, you can quickly lose rear wheel traction.
- Remember that people can do 40+ mph in the corners. Chances are, you're going way slower and therefore have a ton of tire grip available.
- Don't pedal in the corners. Push your outside shoe down hard in the corner and leave it there. When you get more confident, start pedal out of the corner as soon as you can.
The reality is that nobody descends perfectly so feathering the brakes through the apex is almost always faster in real life than doing all of your braking before the turn.

Also do pedal through corners. You need to figure out where the limit is. If you aren’t pedaling out of an apex with 1-2mm to spare in pedal-to-ground clearance you’re losing time.

Robius
Posts: 258
Joined: Fri Jun 19, 2015 12:35 am

by Robius

Take notes on how Cancellara using his upper body to lower his center of gravity so he can have more grip.

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jlok
Posts: 2514
Joined: Tue Jun 30, 2015 3:30 am

by jlok

All good, and I'd say sort out the braking skills / feel first. Ultimately you will need to learn how to brake hard in the curve in a emergency (e.g. stopped traffic ahead in a blind curve).

You need to build up the trust of your brakes and tires (highly recommend starting with Vit Corsa Control G2.0 and Maxxis High Road. they're cheap and very grippy). Test your rear brake on level ground by riding slowly, then progressively brake harder until you lock up the rear wheel. Remember the feel and then practise again at higher speeds.

btw braking in the curve is not a problem depending (and actually necessary in some twisty technical descents) on how steep and how small the radius plus the road surface.

Lastly, is your body weight too far forward on the bike? Check your fit.
Rikulau V9 DB Custom < BMC TM02 < Litespeed T1sl Disc < Giant Propel Advanced SL Disc 1 < Propel Adv < TCR Adv SL Disc < KTM Revelator Sky < CAAD 12 Disc < Domane S Disc < Alize < CAAD 10

usr
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Joined: Thu Mar 25, 2021 5:58 pm

by usr

mikehhhhhhh wrote:
Tue Jun 18, 2024 10:20 pm

It's quite hard to overwhelm the front brake.
Is it, in a turn? If you are close to the limit, the turn angle will create almost as much additional lateral load aka grip requirement as the added vertical load will provide further grip, and there's the forward grip requirement for deceleration added on top

I use the rear more to feel for grip, but it requires a fine touch - done right, you'll overwhelm the rear sooner with a little braking, often giving a little skip that allows you to get off the brake and correct, unlike the front sliding out.
No disagreement here.
Fwiw, with just 2.5 years of road riding experience, I find myself faster than most at descending and cornering. I credit a lot of transferable skills from racing cars and some bike handling from riding mtb as a kid.
How much road crashing experience in those 2.5 years? Wouldn't be surprised if most never fully recover in their rule#64 cycles.

usr
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by usr

TobinHatesYou wrote:
Tue Jun 18, 2024 11:43 pm
jdms2k wrote:
Tue Jun 18, 2024 9:11 pm
Super helpful thread as I'm working on my descending as well!

Additional tips for beginners:
- Finish all of your braking before the turn. Braking during a turn reduces tire grip because you're asking your tires to grip for the turn as well as grip to slow down. Also, do not brake with your rear brake unless you really know what you're doing. Otherwise, you can quickly lose rear wheel traction.
- Remember that people can do 40+ mph in the corners. Chances are, you're going way slower and therefore have a ton of tire grip available.
- Don't pedal in the corners. Push your outside shoe down hard in the corner and leave it there. When you get more confident, start pedal out of the corner as soon as you can.
The reality is that nobody descends perfectly so feathering the brakes through the apex is almost always faster in real life than doing all of your braking before the turn.
And then there's all the acceleration that can happen during the turn, unless brakes are at least feathered. It's possible to build a turn that cannot be safely traversed without braking even from a standstill. Perhaps in-turn acceleration isn't much of an issue for climber physique types whose terminal velocity isn't all that much higher than safe cornering speed, but for heavy low cdA riders, no braking after turn start is only nice when it's possible.

repoman
Posts: 42
Joined: Mon Jun 10, 2024 3:28 pm

by repoman

[/quote]

So under the hardest braking, only the front brake should be used.

[/quote]

This seems crazy and a great way to flip over the bars!
You have to use both. Shift your weight back behind the saddle and get low if you need to brake irregularly hard and brake in a straight line before the corner.

proffate
Posts: 86
Joined: Sun Oct 10, 2010 2:39 am

by proffate

I find that descending the same road multiple times with different bikes helps me understand what the inputs are (basically fore-aft and lateral weight distribution) and how each bike reacts to them. This is how I finally realized that with a high trail bike, you just need to start turning before it looks like you're in the turn, and also that you don't need to be as worried about getting knocked off your line (a hold-over from other stiffer, twitchier, narrower-tire bikes I had ridden in years past).

The only other specific advice I'd give is that "outside foot down" is a vast oversimplification. I feel like I can "feel" the weight distribution and grip better when I keep my feet more equally weighted, at 3 and 9 oclock, except in the hardest of turns.

> How much road crashing experience in those 2.5 years? Wouldn't be surprised if most never fully recover in their rule#64 cycles.

Me, exactly. The broken jaw from disproving

> your tires have way way way more grip than you think

never really fully heals.

repoman
Posts: 42
Joined: Mon Jun 10, 2024 3:28 pm

by repoman

I find the 3 and 9 o'clock positions much better stance for descending too and dropping outside foot for hairpins.
Helps a lot is to look at where you want to go, not where you are going, look farther up the road instead of focusing on the immediate road in front of you. That helps all around, even on slow stuff like in CX when you have a very narrow track to keep the wheel on.

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

by TobinHatesYou

You’ll know when you need to drop the outside foot. It’s not just for hairpins but railing sweepers at very high speeds. Standing on the outside foot is more of a trick to hang your butt slightly off the outside of the saddle rather than “putting weight on the pedals.”

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