I've been riding for 25 years, just the last 6 in Colorado. I retired from mechanical engineering 6 years ago at age 50, so I've had a lot of time to ride in the mountains since then.

You admitted to having no motorcycle experience. That's where you really learn about countersteering. If you ever try a motorcycle, after many years of cycling, like I did, you'll find that even a sport bike turns slowly and requires a lot of countersteering effort compared to a bicycle.

As for my cornering experiment yesterday, no it was not squirrelly and it did not require corrections. It was really quite easy to negotiate sweeping turns at 38 mph using one hand, without the outer foot down. I could have done it faster with both hands and outer foot down, but not as you described. You never have to apply weight to the outside of the bar and you better not expect the bike to keep turning if you don't keep countersteering. The amount of effort required to countersteer a bike is just very small - so small that some people don't even realize that they are doing it.

You misunderstand what I wrote. Pushing on the right is the same as turning left - countersteering in a right hand turn. You're also making the assumption that speed remains constant, the amount of countersteering force is constant and the radius of the curve remains constant. Any or all of those things are more likely to be changing than remaining constant - particularly with a bike that is not being pedaled through a curve. IMO, the reason I drifted to the centerline was because I failed to keep applying the required countersteering force. Mountain road curves are not truly circular, with a single fixed radius. Quite often, a rider is forced to follow a narrow clean path created by car tires that is not much more than a foot wide. You can't assume that a corner can be negotiated along some ideal curve, like those shown in those diagrams for a rider on a race track.

As simply as I can put it, I firmly believe that a bike will NOT keep turning by itself, after a turn is initiated, unless the rider countersteers continuously. Anyone who has ridden a motorcycle knows that this is true, because it requires so much more countersteering force than a bicycle. You don't just give the bars a brief nudge to the right and expect the bike to lean to the right and keep turning to the right all by itself - my motorcyle never did that. You keep pushing on the right side of the bars until you want the bike to straighten up and quit turning.

All I can recommend to others is to experiment, but keep in mind what it takes to sharpen the turn radius - more countersteering.

The only correction I'd make is the idea of yanking. Bicycles require a very small amount of force to countersteer - so little that most people don't even realize that they are doing it. Some riders honestly think that they steer the bike by leaning their body. I've never noticed any need to apply any pressure opposite of the countersteer to quit turning. All I'm conscious of doing is not pushing on the right side of the bar (in a right hand turn) and the bike straightens itself up. I might be doing someting more and not realizing it, but I don't think so.

I don't care about motorcycles! Most people who read these forums don't care about motorcycles. I don't need a motorcycle to teach me how to corner on a bicycle! Nor does anyone else. I do have decades of experience with riding in the Colorado mountains at speeds that would scare some motorcyclists. If you want to go talk about motorcycles, go find a motorcycle forum.

You have stated above exactly what I have been saying all along "a motorcycle...requires a lot of countersteering effort compared to a bicycle" and I have pointed out why. So let's get off this damned motorcycle tangent!

The emphasized statement exactly what I have described.

I said, and will continue to say, that you push down on the bars and pedal. The video I linked to for n8tron says the same thing as well as numerous other websites on bicycling. Once in a corner you shouldn't have to do much steering at all on a bicycle nor should you have to do too much steering on motorcycle because the geometry of the vehicles will tend to steer them towards the direction of the lean. From Wikipedia:

I agree with one exception...I think the diagrams on early/late apexing were useful. I live and commute in the twisties and IMO the biggest cause of poor and/or slow cornering is early apexing.

You should never be pushing down on the bars, you should be pushing forward on the inside.

There's a lot of difference in geometry of different motorcycles...some are easy to maintain the lean on, some you have to work to keep turning.

At speed, bikes (human- or gas-powered) naturally want to stand up and go straight. It is only at very slow speeds that they would fall down on their own.

sheesh...now I'm going to go out and ride my bike, with my aching head full of vertexes and centripetal forces and countersteering angular momentums and I don't even remember how I used to take a corner anymore - I'm just going to flat out crash!

Htfu

You can push all you like but the fact is that once you are in a turn of a fixed radius your front wheel will be turned toward the turn. If you're turning right the front wheel will be turned to the right. No question you need to apply some force but that is not the same as countersteering as the steering angle is in the same direction as the turn. Read the wiki page (and associated references) I quoted earlier. It explains everything quite clearly.

Last time I tried using WikiPedia as a reference in a paper to get published, it was denied as a credible source.

Read wikipedia? Ride a bicycle, or better yet, a motorcycle through thousands of twisting turns like I have. I have to ask whether you have any real motorcycle or bicycle experience in the mountains? I've ridden bikes for 25 years but never rode anywhere with high speed hairpin turns, until I moved to Colorado, 6 years ago. Anyone can post a link to an encyclopedia, but that doesn't mean that you understand how to apply the information.

Both bikes and motorcyles naturally want to go straight and be upright at high speed unless countersteering force is applied to lean and turn the bike. Perhaps the issue is that in reality, we're seldom in a "fixed radius" turn. Speed is also never constant and that affects the turning radius. When I'm turning to the right, I never push on the left side of the bars - that I'm aware of - to turn the wheel into the direction of the turn. I use my right hand exclusively to vary the amount of countersteer. I may let up on the pressure and perhaps the wheel naturally turns into the curve, but I never intentionally turn into it. IME, you have to make continuous minor adjustments to the countersteering force. If you're really doing these types of turns, you don't want to be looking at the wheel and the bars unless you want to crash. You have to keep looking ahead at where you want to go. Once you've done enough of cornering of this type, it comes naturally, but if you don't remember the crucial rule to apply more countersteering to tighten up a turn, a wreck can be the result.

When I did my experimental turns on Friday, I went through several high speed turns (38 mph), using only the inside hand (the other hung to my side) and I never had to pull back on the bars. All I did was vary the countersteering force -pushing on the right to turn right. I also didn't need to weight the outside of the bar or the outside pedal as was claimed to be so crucial.

I guess those pictures of the motorcyles that were posted, showing the front wheel turned away from the turn with the bike leaning into the turn didn't sink in. That's how they're keeping the bike leaned over and turning sharply.

I suggested you read the wiki page and the references but it seems like you didn't. You don't need to ride hills in CO to understand physics.

Agreed. That is how a turn is initiated.

I don't know where else you think would be a good place to put your weight other than the outside pedal. It may not be necessary to turn but if you want to go fast that's where you should put your weight (unless the roads in CO are perfectly smooth).

You mean the one with the bike sliding? Next you're going to try and convince us this picture proves you need to countersteer a car to get around a corner as well.

If you don't understand the differnces between how a car versus a 2-wheel vehicle steers, then this discussion is worthless.

Try releasing your outside hand from the bars while cornering and tell us what the inside hand is doing. The forces on a bicycle handle bar is so small that it's hard to differentiate from the forces needed to support your upper-body weight. So try it on a bike with more vertical position to keep the weight on the saddle, like a beach-cruiser. Feel what the inside-hand is doing in the middle of a steady-state corner. Or try the same on a motorcycle at steady-state cornering. Not accelerating, not under too much power to cause a slide, far enough away from maximum-grip to eliminate loss of traction from affecting the results.

Try it for yourself and get away from the armchair. After all, I can cite numerous references that the Earth is actually flat. Real-world experience will give you valuable data.

agreed.

Have you ever ridden down a tight spiral ramp (like at some parking garages)? If you do so, it will be quite obvious that your front wheel is not pointed at the turn.

You mean like how this tire isn't pointed into the turn



or this one



or any of these



You want dirt? This one seems to be pointed in the general direction of the curve and certainly not away from it.



as is this one



It's physics and centripetal force that gets a bike around a corner. The bike is going to go in the direction the wheel is pointed. Even countersteering to initiate the turn (right turn for example), the bike's wheel goes towards the left before you can make it fall to the right. The force acting on the wheels to turn the bike is the centripetal force acting on the tire patch. Left to its own devices the bike will continue in a straight line.

Coming out of a corner and straightening up would have the front tyre aimed into the corner. Unless we've got a slow-mo head-on video of the entire turn, we don't know where in the turn these riders are.

You want to explain the physics and centripedal forces involved? What makes the bike go in a circle instead of going in a straight line? Because it's possible to have a bike leaned over AND going in a straight line as well. What's the difference between that bike and one that's going around a curve?

Sorry I prefer not to ride in parking garages. I will give you a simple experiment to do however. Next time you go for a ride and have some open road, pretend you are on a slalom course and weave your bike back and forth. When you're carving a left turn have a look at the back portion of your front wheel. It will be on the right side of the downtube, i.e. your wheel will be turned to the left following the turn.

As DannoXYZ pointed out, we don't know where in the turn the riders are, nor how tight the turns are. So these pictures don't tell me anything.

That's too bad, because you would learn a lot about the physics of two-wheeled vehicles. I have ridden my motorcycle in many parking garages, and used to bicycle commute regularly across a freeway overpass for pedestrians/bikes with a spiral ramp.

These are extended turns with a fixed radius, which are often difficult to find out on the road. If you ever cared to do the experiment, you would find that to ride down them, your wheel doesn't point down the ramp, but instead points at the wall. If I still lived close to that overpass I would take a video.

I live in the twisties, and all my roads are a slalom course. I ride bicycles and motorcycles daily on these roads, and I am very familiar with how my bikes turn, thank you.

You are kidding, right? Look at the pictures. In the second and third picture I posted, you can clearly see the apex of the turn. The guy in the blue and white outfit fourth back in the picture (count helmets) is at the turn's apex...or at least close enough for government work. His wheel is clearly turning towards the corner. Perhaps you could argue that it's a trick of the lens and the guy is really 150 yards away and about to fall over in a crash but that would be streeeeeetching things a bit much.

Yet another image:



While all of the riders' front wheels are turning towards the corner, the rider on the far right in the green striped shorts is clearly turning his wheel towards the corner.

First most of this is well covered in the Wikipedia article. I know you'll pooh pooh the use of wikipedia but, quite frankly, there's to much information to go reposting it. I'll even go look at some of the quoted papers when I can get access to them.



In the above picture, the net fictional force on the wheel are the orange arrows. The lean of the bike and the frictional force on the wheel pull the bike around the corner as shown in the net torque arrow around the steering axis (the magenta arrow). It's the only way a front wheel steered vehicle can go around a corner.

A bicycle can be leaned and made to go in a straight light but there you are really using counter steering. To keep the vehicle moving straight while leaned, you have to apply torque to the handlebars in the opposite direction of the lean. Here you are steering into the turn to keep the bike upright and the rear wheel tracking the front. Remove that torque and the bike will veer off in the direction of the lean because the overall centripetal force on the tire patch will pull the bike in that direction.

Here is a computer animation of a bike going through a series of curves. Notice that the wheel is turned towards the curve on each oscillation. The rear wheel doesn't track the front wheel exactly because it has no steering axis.

There is only one way to go around corners faster - practice going around corners faster. This whole thread is worthless in practice.

Below is a link to a good website in general, specifically to the page on descending techniques.


https://www.flammerouge.je/content/3_...06/descend.htm

Right, so you wear gloves and don't wear a helmet?

Wiki rocks - now I'm going to go see f' myself.

Wilber Wright is right; for most riders, the understanding of bike handling is visceral.

Motorcycles weigh more than bikes, hence their response to rider shift is much less; the tyres are also wider.

In the local crit, many riders seem to turn late; they exaggurate the (countersteer) setup and scrub speed carving it on a shorter radius.

It's a setup.

^ this

motorcycle has more mass than a bicycle.
motorcycle typically has more mass than the rider and the bicycle, much less.

what you're doing in both is shifting weight to the inside of the turn.
what's different is where the majority of the mass is.

since a motorcycle weighs more than the rider, you need to initiate the turn by shifting the weight, which will be by counter steering.
since a bicycle weighs less than the rider, you can simply lean over to shift the wright and initiate the turn.

it's not as obvious on the bicycle.

There you go again. WikiPedia is NOT a credible source. It's not an admissible reference for high-school papers, much less university/phD level dissertations. Where is a sideways force coming from? The only forces on a moving bike is longitudinal. Friction pushes you back and your momentum pushes you forward. Where does the sideways force come from and what generates it?

Let me give you a hint, for any given lean-angle, there are three states. There is a "balanced" radius of turn and speed such that no steering is needed. There is also a radius & speed where you need to "turn into" the turn and there's a radius & speed where you need to "turn out" of the turn. Since there are three variables, we have a cartesian-product of 9 possible states of cornering to describe. Look up camber thrust and camber roll as it relates to rounded tyre profiles.