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The general advice about cornering is to lean the bike, not the body, to put pressure on the outside foot, and not to brake or brake only with the rear brake if absolutely needed.

--me

There are differing cornering techniques for road vs mountain bike riding. I would say that cornering on dirt is much more dynamic than on pavement.

--joelmdev

Supposing that what I am saying about cornering on dirt is correct, how is cornering on (dry) pavement different?

  • Does one lean with the bike?
  • Does the bike stay more upright?
  • Is the pressure more evenly spaced among both pedals?
  • How can one get feedback when the (front) tire is about to loose traction?
  • What does "dynamic" mean in this context?
  • Is it customary to place the inside foot on the road in order to have three contact points and prevent tipping/sliding out?
  • Is the weight of the rider evenly spaced (chin over stem, butt over seat)?
  • Is standing up to gain additional "acrobatic" space i.e. freedom to more one's weight around rapidly ever used?
  • What about slippery pavement - water, snow, sand?
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And now someone will say I am asking more than one question ... –  Vorac Nov 29 '13 at 15:29
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You are asking more than one question! –  joelmdev Nov 29 '13 at 16:24
    
"... different from ..." surely? –  Beetroot-Beetroot Dec 4 '13 at 19:58

3 Answers 3

up vote 9 down vote accepted

First, let's answer the first to questions together, as they are closely related.

Does one lean with the bike?

...and...

Does the bike stay more upright?

Short answers are yes and yes in most cases.

To elaborate, let's take a look at what you're trying to achieve when cornering. I found this image recently and I think it does a great job of visualizing the basic physics of what's happening when you take a corner on a bike:

enter image description here

In a turn, whether you're leaning the bike, or your body, or both, that "local gravity" line is what's keeping you from highsiding or lowsiding. The center of gravity and that center line just moves depending on what you're leaning and how low you're getting.

Do a search for mountain bike cornering and a search for road bike cornering. Notice how centered the road riders are compared to the mountain bikers. One of the big reasons for the "lean the bike" advice is to engage the more aggressive side knobs on a mountain bike tire. On a road bike this is not necessary. With a mountain bike you spend a lot of time skirting the line of traction. You lose it and regain it often. Many of the techniques for cornering on a mountain bike are to keep you on the traction side of that line and to recover without crashing when you cross it. Many of these techniques aren't applicable on a road bike, where in most cases you either have traction or you've just crashed.

You'll also notice on the mountain bike cornering images that in big berms the riders are typically more centered over the bike, sharing the posture of the cornering roadies. That's because when traction isn't an issue being centered over the bike is the most balanced and stable way through a turn, and that's why you see road riders using that posture most of the time.

Is the pressure more evenly spaced among both pedals?

No. The advice on weighting of the pedals and the bars stays the same. Drop the outside pedal and weight it primarily, weight the inside handlebar. Note that the primary reason that you're weighting the inside bar is to initiate countersteer.

How can one get feedback when the (front) tire is about to loose traction?

If you've got everything weighted properly and you're lucky, the back will cut before the front does, at which point you've got a fraction of a second to stand the bike back up, or you crash. If the front goes first, you crash. A lot of knowing the limits of road bike tire traction comes from experience, and crashing.

What does "dynamic" mean in this context?

There's a lot more movement of your body on and over the bike on a trail than on the road. The more technical the trail, the more this is true. The "lean the bike, not the body" advice is a good rule of thumb, but it is not a one size fits all solution for mountain biking. There are so many different types of turns in mountain biking- fast, slow, bermed, off-camber, uphill, downhill, steep, flat, loose, rocky hardpacked, etc, and nearly infinite combinations of each. Many categories of turns deserve their own questions for cornering technique.

Is it customary to place the inside foot on the road in order to have three contact points and prevent tipping/sliding out?

Typically not during the turn. I've seen it done it the wet sometimes, but taking your foot out/off of the pedal during a turn will affect up your balance, especially on a road bike. Getting your foot out of pedal at the last minute is really hard, especially with road pedals.

Is the weight of the rider evenly spaced (chin over stem, butt over seat)?

Somewhat dependent on slope/incline and speed, and whether you're on the hoods or in the drops, but largely yes, this is correct.

Is standing up to gain additional "acrobatic" space i.e. freedom to more one's weight around rapidly ever used?

On a road bike, typically only for slow speed maneuvers. There are probably exceptions but I can't think of them at the moment.

What about slippery pavement - water, snow, sand?

Sloooow dooown. The more treacherous the riding surface, the more upright you need to keep the bike and your body.

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Great info! Care to elaborate why the rider stays in line with the bike, instead of leaning only it? –  Vorac Nov 29 '13 at 17:22
    
When riding on ice without spiked tires, don't turn, stop or speed up. you need enough momentum to get past the ice. –  hildred Nov 29 '13 at 22:39
    
Still, why would "lean the bike, not your body" be inapplicable in this situation? –  Vorac Dec 2 '13 at 9:16
    
@Vorac If you have good tires, and smooth, clean, pavement, you can corner very sharply on a road bike, at very high speeds. If you're doing 40km/h, and want to make a sharp 90 degree turn, you can do it, but you're going to have to lean pretty aggressively. If you don't want a pedal strike, then leaning both bike and body would seem to be the way to go. –  John Doucette Dec 2 '13 at 14:29
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@Vorac edited to add quite a bit of elaboration in the first half of the answer –  joelmdev Dec 3 '13 at 2:19

Cornering a road bike at speed (revised after feedback from joelmdev)

  • Firstly your tires must be hard - near the maximum pressure written on the side wall. Riding soft tires is a recipe for death under oncoming traffic, because they don't have as much grip and just slide out from under you.
  • For wet or loose surfaces, slow down. In these conditions, all your MTB cornering techniques apply.
  • For dry conditions and a trustworthy surface, at low speed you can do whatever you like. The real technique is for higher speeds: 30 kph (20mph) and up.
    At speed you must lean with the bike. You lean the bike to make it corner, rather than steer it. At these speeds your weight should be evenly distributed between handlebars and peddles: no weight on your seat.
    At low speeds you would have the outside peddle low, partly to stop the inside peddle hitting the ground in tight corners. But at higher speeds, you need to be balanced and more responsive. Having one peddle low means you are pretty much on your seat, and if anything lets go your weight just pushes it faster. You see the pro riders in this position - they are ready to put on the power as soon as they can, are absolutely sure of the surface, can see through the corner, and have rock hard tires. When those things are not all true, I prefer the peddles to be horizontal, with either foot forward, evenly weighted.
    Hands on brakes. If you must brake, do it evenly. Test your brakes before entering a fast turn, and use them evenly in the event that the corner tightens or you hear that tell-tale noise the front tire makes before stepping out. Be as gentle as you can.
  • For faster corners move your weight back slightly more. If the back starts to slide you can correct by bringing your weight forward and counter steering, but if the front goes you are toast. So get your weight back more. You really need lots of practice before going faster. There is almost no time to react. You have to learn the "feel" of when it's going to let go (the front tire often makes a different scrubbing sound, but not always). You can lose a lot of skin if that happens! So don't go fast on corners you don't know yet.
    Never change your line through the corner unless a crash is imminent. At high speed changing your line is virtually guaranteed disaster.
  • As you get even faster (60-80 kph, 35-50 mph) the bike gets more stable on the road due to the gyroscope effect of the wheels. At these speeds the consequences of errors can be fatal. A new risk is that if you don't lean with the bike the cornering forces can pull the tire off. From experience I can tell you that the wheels stop rotating half a turn after that as the tire jams in the forks, and then you head off on your own. The landing is not pleasant.

What I have written is counter to a lot of the wisdom found on bicycles.stackexchange.com. The difference I think is in the context; here I am talking about cornering at speed. My source is the 50+ years of cycling I have experienced, starting from growing up in a hilly area, in a cycle-racing family. I first exceeded 100 kph (60 mph) in 1970, and almost every week one of my rides includes one very tight corner taken at 40 kph (25 mph), as fast as the cars can do it, and another taken at 50+ kph (30 mph).

Enjoy.

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From your other posts I believe you mean that you are riding your MTB on the road. This answer is intended those who get here and are on road bikes. –  andy256 Dec 1 '13 at 12:09
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I think there's a lot of really unsound or unclear advice in this answer, especially in terms of weighting and braking. –  joelmdev Dec 1 '13 at 23:55
    
@joelmdev Thanks for the feedback. Hopefully it's clearer now! –  andy256 Dec 2 '13 at 7:14
    
I would add that if you decrease tire pressure in the wet then you will have a little more contact surface with the road and hence more grip. –  robthewolf Dec 8 '13 at 14:27
    
@joelmdev Everybody has their opinions. I certainly prefer when people give a reason though! –  andy256 Dec 17 '13 at 20:47

This advice - from above- could you get killed:

Firstly your tires must be hard - near the maximum pressure written on the side wall. Riding soft tires is a recipe for death under oncoming traffic, because they don't have as much grip and just slide out from under you.

It's junk from a self-appointed expert. Sorry: yes, you've cycled 50 years, but you're still wrong. Grip increases with contact patch size and you're telling people to reduce it instead. This is what a professional coach (who learned his cornering wrenching for a pro criterion team) has to say:

http://myworldfromabicycle.blogspot.co.uk/2010/04/hermann-criterium-17april2010.html

Dave, I read your blog about cornering and felt compelled to add commentary. You make reference several times about keeping weight over the center of gravity, but then later add to point the knee into the turn, which in fact moves valuable weight outside the center of gravity (or more importantly, away from above the contact patch of the tyre). The reason pointing the knee towards the inside of a turn helps is because it facilitates the hips rotating, which guides you through a turn. Bicycles are steered with hips, not hands. Unfortunately most cyclists are so tight through their hipflexors they cannot keep their knee above the tyre while rotating their hips into the turn, thus losing the benefit of additional weight atop their contact with the road. As for other ideas....tubulars are not meant to be run @ highest of pressures. In fact, I would run tyres for the team @ 90 front and 105 rear on technical courses like Downers Grove, but only 85/95 if raining. My riders absolutely loved it, and rarely crashed because of it. The supple nature of the pressure allows the tyre to soak up lots of the effects of cornering, and keeps the tyre consistently in contact with the road, which is great for high speed cornering and power transfer. The energy potentially lost is negligible compared to the security and performance of properly inflated tyres. Keep in mind, this is from 284 days of racing with 9 bikes worth of tubulars per day. Never a rolled tyre, and significantly fewer punctures and crashes, especially in wet conditions."

When you increase pressure, you reduce grip. When you reduce it, it increases. If you're running in conditions where you need more grip, do what the professionals do and reduce pressure.

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