base2 

6GjMLjB_d by Richard Mozzarella, on Flickr

This thread has illuminated who in this forum is a "bike rider" & who has competent command of their bicycle. The bike riders have no idea what they are doing. Those in command intuitivly understand they are on gyroscopes & consciously shove them around in combination with gravity & velocity to actually control their vehicle.

It was previously mentioned to take a motorcycle safety course. There is a reason many state require such a course. There is also a reason the wash-out rate is relatively high. Competently commanding a two wheeled vehicle is a skill many don't posess & for whatever reason simply can't learn inspite of how easy it is to simply "balance" or "ride upon" such a contraption.

In rare form for Mr. Base2...Imma come right out & say it: livedarklions doesn't understand that the vehicles plane of reference is independent of that of the road it is ridden upon. Actively inducing a lean/fighting a lean by pushing on one side of the handlebars or the other, or modulating pressure for course corse correction or changing power input to control turning radius is countersteer from the vehicles perspective, no matter the side to side balance or current lean in reference to the outside world. All the vehicle knows is gravity is still operating in a plane drawing a straight line between the vehicle/rider center of gravity & the wheels contact patch on the road. From the vehicles perspective the operator is moving the road & controlling gravity. As far as it knows it is upright, coordinated & balanced at all times.

Any first year physics student that had to plot out how the Earth pushes you when you walk or how a particle spirals into a gravity well & doesn't know it's not going in a straight line in reference to some arbritary observer, knows this stuff.

livedarklions

Imma going to say this--when anyone actually agrees on what countersteering actually means, then we can have a talk. If all you're saying is that any time the hands are counteracting or correcting any effects of a lean, it's countersteering, well, duh, of course that's happening. What I understand countersteering to mean is that the turn is initiated by a turn of the handlebars in the opposite direction. Frankly, I don't care what the bike's perspective is, all I know is that I never initiate a turn by turning my handlebars in the opposite direction. I also don't give a rat's behind about racing technique, but I'm actually a very competent bike handler, thank you very much.

My perception of what is going on, and again I don't care about the bike's "frame of reference" because I have one and it doesn't, is that steering from the handlebars initially at speed is not practical precisely because it's too easy to turn the wheel, so it's simply too crude a method of control for major attitude adjustment. Lean is also somewhat crude, but your cns has all sorts of unconscious mechanisms that will keep you from overdoing it to the point you'll flip over. So I perceive what's happening as my lean initiating the turn and my hands using their fine motor skills to control the turn with very small adjustments of the handlebars.

The fact that you guys keep going back to motorcycles actually demonstrates that you can't get around the fact that the effects you're describing are too small on the bicycles to be perceived. You also are obviously unaware that it's been demonstrated that gyroscopic forces play little to no role in bicycle handling by having people successfully ride and control bicycles where those gyroscopic forces are counteracted by wheels spinning in the opposite direction, so if your perception is that you are primarily riding on top of a pair of gyroscopes, your mental model is fundamentally flawed. But hey, if it helps you to think of it that way, I don't care.

I love that these conversations always degenerate into someone oversimplifying the physics, calling other people ignorant, moving the goalposts on what countersteering is, and exposing the fact that no one really understands how the human cns actually balances itself. I think it's a bit of a mystery why we can instinctively control the bicycle--3 year olds can balance and turn a bike, for crying out loud.

wolfchild

Shorter stem = faster more responsive handling...Longer stem = slower less responsive handling, but it's not just about the stem length...The geometry of your frame and the angles of the head tube also have a very significant effect on steering and handling....My advice to OP is to just go ride your bike and experiment with different stems to see how it handles...Just ignore all the nonsense and ******** about physics...You don't need to study and understand physics in order to ride a bicycle, you don't need to take motorcycle courses, you don't need to study complex graphs and charts in order to ride a bicycle. Just go out and ride your bike, time in the saddle is the best teacher.

DaveSSS 

I can make tight high speed turns on mountain descents using one hand in an open position that prevents any steering input other than a continuous push on the right to turn right. No body English required. It's incredibly simple. If the turn radius is too wide, push a little harder. To quit turning, quit pushing. No definition of counter steering is required. It's the continuous and controlled pushing that keeps the bike turning. lt doesn't matter if I'm riding a bicycle or motorcycle. Both work the same.

The most common bike wreck occurs when an uneducated rider panics in a turn and quits pushing to steer, usually because the turn radius is too large. Then the bike goes straight and either off the road or into the opposite lane. You can find videos or pictures of pro cyclists with their feet off the pedals and heading off the road or into a guard rail. They paniced and quit pushing on the bars. If steering was maintained, the result might still be a slide out, like you see in a motorcycle race. I've done that on my bicycle when there was too much sand on the road and lost traction. In those days 23mm tires with 110 psi were the norm and traction suffered. A mountain road with a 30 mph speed limit is not a groomed race track.

El Fug

The Wikipedia article on countersteering is really good. It touches on many of the points of contention I've seen in this and other threads.

https://en.m.wikipedia.org/wiki/Countersteering

base2 

Maybe you've come to your understanding with out any formal or specialized training? Sure, a 3 year-old can figure out how to ride upon a bicycle. A conscious understanding of the physics involved will make anyone a better cyclist.

It is funny that you think we don't understand how small the inputs & effects are in a 200 pound bike/rider system (180lb rider, 20lb bike) because we are citing a 700 pound motorcycle/rider system (180lb rider, 620lb bike) to explain the dynamics involved. The rider of a bicycle represents ~3x the system influence. Yet the maneuverability of either system with a sufficiently skilled rider is the same.

You would do well to take a state certified motorcycle safety course. Heck, do it to prove me wrong. The skills learned there there might galvanize your already existing knowledge & increase your handling skills to be a cut above the average cyclist.

ofajen

There should be no problem with using the stem length that gives you the proper fit. There are differences in types of bar and steering geometry between bikes, but varying stem length on the same bike shouldn’t create a radical change in handling. And getting the fit right is really important.

Otto

DaveSSS 

This article is garbage. It doesn't tell how to steer your bicycle or motorcycle. You don't counter steer to exit a turn, just quit pushing on the right side and the bike will straighten up.

El Fug

What an asinine thing to say. It agrees with much of what you've been arguing.

terrymorse 

That's an overstatement of what's known, and probably incorrect.

What has been demonstrated: a moving bicycle may still balance itself without gyroscopic forces

What has not been demonstrated:

• how much of an effect on balancing comes from gyroscopic forces
• the relative effect on balancing of: trail, steering center of mass, gyroscopic forces

terrymorse 

That all depends on what your definition of "counter steer" is, since there is no formal definition.

DaveSSS 

You don't counter steer left to exit a right turn. All you do is quit pushing on the right side. No left hand action needed.

tomato coupe

Where does Wikipedia state this?

DaveSSS 

Look at the drawing. It says counter steer left at the beginning of the turn and counter steer right to exit. A simple right turn only requires pushing on the right side of the bars.

They've taken something simple and made it much more complicated than necessary.

tomato coupe

A motorcycle rider maintains pressure on the right handle during the static portion of a right turn. To end the turn, the rider lessens the pressure on the right handle. Lessening pressure on the right handle is equivalent to adding pressure to the left handle, which is counter steering right.

As terrymorse and the Wikipedia article both pointed out, there is no formal definition of counter steering. You may not like the diagram because you don't subscribe to their use of the term counter steering, but the physics in the article is pretty good.

Darth Lefty 

In mountain bikes the short stem goes with the frame geometry. Since the advent of droppers, riders now get down but not so much back. The designers are going for extended front-center, as much as the total reach to the bars will allow. For a few years now with that already at the limit they’ve been decreasing the head angle to move it even further. But that has resulted in very floppy steering. But how do you put the wheel any further forward without going under the mid sixties? For standard components there’s an awkward zone where the stem must go from +35 to -35 and solutions to that tend to be integrated.

I don?t make bicycles. I make weapons systems. | Peter Verdone Designs

livedarklions

I'm quite sure my handling skills are several cuts above average, thanks.
Bike handling is significantly easier than motorcycle because, as you point out, the rider on the bicycle can manipulate the vehicle with so much less effort, so all that "motorcycle safety course" is totally irrelevant if I have no interest in riding motorcycles. I also have no interest in "proving" you wrong as I have no reason to believe that your skills are better than mine or that mine are somehow not up to those I need.

livedarklions

Well, that certainly puts the lie to the idea that the physics here are well-understood.

wolfchild

You don't need to take motorcycle courses or physics courses to become a better cyclist....I learned handling skills by doing a lot of mountain biking and also by riding fixed gear bike in heavy traffic and by riding in icy slippery winter conditions. Time in the saddle is the best teacher and the only way to learn and understand all the physics involved in bicycle handling.

DaveSSS 

In order to provide meaningful training to prospective riders of motorcycles, the course I took did not even mention the physics involved in steering because it's complicated and adds nothing to the actions the rider needs to take to stay on the road and in the desired lane. That's why the instructor emphasizes only pushing with one hand - right hand for right turns and left hand for left turns. That’s all that's needed to complete a successful high speed turn. Vehicle speed is also mentioned as a method to increase or decrease turn radius. If you're pushing hard in a turn and not turning sharp enough, slow down. In my area, a woman died during a memorial motorcycle ride for her dead son, who died in a motorcycle accident. Riding in a group, she was the only person who failed to stay on the road in a turn. You may only get one chance to prove that you really know how to steer. If you've never ridden a winding mountain descent, practice your steering process at a moderate speed on a gentle slope so you're sure that you know what to do when the unexpected happens. I've ridden many thousands of high speed turns, starting in 2003 and haven't gone off the road yet. I took 8 years off the bike, but now I'm back to my regular 5000+ miles per year. I've logged over 50,000 miles on Colorado roads.

terrymorse 

That's true.

To straighten out a right turn, you must initially steer farther to the right (not left).

Some call this additional turn to the right "countersteer". Others may say no, countersteer occurs only when initiating a turn. But that's simply quibbling over word definition.

Whatever name you give it, the fact remains that in order to end a right turn, the handlebars must first turn farther to the right.

terrymorse 

Just because nobody has bothered to do the experiments, that doesn't meant that the physics aren't well-understood.

Having not taken the measurements, I don't know how much livedarklions weighs at sea level, but I have a pretty good handle on the physics involved.

DaveSSS 

Perhaps, but if you first understand to push right on the bars to turn right, you're way ahead in the learning curve. I'd been riding road bicycles for 19 years before taking the motorcycle training course, which you MUST do ride a motorcycle legally in Colorado. The few sentences it took to describe the steering process were a real eye opener. I went right out and practiced the technique on my bicycle,but I also used it immediately to safely ride my new motorcycle on twisting mountain roads.

tomato coupe

True*, but also not in dispute. No one, including the Wikipedia article, has stated that you counter steer left to exit a right turn. It was offered as evidence that the Wikipedia article was garbage, yet the article states the opposite.

*Depending, of course, on how you want to define counter steer.

afm199

This, and here's from the motorcycle world: Weight distribution on motos is critical. In racing a the top levels, raising or lower the front or rear will be done in as small as 1 mm. changes. More weight on the front leaves it better planted and relatively easier to initiate turns, more weight on the rear leaves the moto less likely to "spin up" the rear tire and harder to turn.

Lots of weight on the rear leaves the moto vague and twitchy.

As counter steering was mentioned after posting, an edit. Countersteering is used on motos to initiate a turn, and it's often a abrupt and hard push. That does not continue throughout the turn. Once the moto ( or bike) has reached lean angle and centripetal force is keeping the line, counter steering pretty much stops. In the photo below, to initiate the turn, I pushed on the inside bar fairly hard. Once the turn was initiated, minimal exertion is needed to continue the turn. Gyroscopic precession is real. At the end of the turn, to stand up the bike, I'm relaxing the last bit of pressure on the inside bar, not pushing the outside bar.