Helmet Head

For those who are interested, this thread is to discuss the topic of what makes a bike turn (a tangent from the skills thread).

Is it steering? Counter-steering? Leaning?

Can a bike with the headset welded and the bars set straight ahead turn? What if you walk this bike pushing it by the seat and lean it. Will it turn, or continue going straight?

For those who might think a counter-steer is always required, what about this?

EDIT:
Cool, the moderators merged the poll into this thread (Thanks!).

Here's the question:



If this guy, who is turning left, wants to turn more left, without shifting his body weight, does he need to turn the handle bars a bit left or a bit right?

Bekologist

who the heck thinks a countersteer is always needed to turn a bike?


I'm going to check with a few of the three and four year olds at the bike shop this week, and i'll get back to you about what makes a bike turn.

fascinating topic.

its the rider that makes a bike turn!

pj7

Yup, nope, yup.

Yup

Depends on if you are adding any kind of counter pressure to it. By default, it will start to turn in the direction is is being leaned. I believe it is called castering... or cambering?? Not sure the exact term.

Can't view videos where I am. But counter steering can work, depending on where the center of gravity is and other factors. But if I were leaning my bike to the right, deeply, making a sharp right turn, countering with the weight of my body shifted to the left, and decided to turn my handlebars in the direction away from the turn (countersteer), I'd go down faster than a cheap hooker when you flash a $50 in front of her.

Helmet Head

If you don't want to take some one else's thread topic seriously, the polite thing to do is stay quiet, Bek.

Bekologist

I do try to take you seriously, head. I'm going to be checking with some of the three and four year olds at the shop this week and see what they think about steering bikes, get some expert analysis on this puzzling topic for you.

Helmet Head

And if my threads had few, if any, responses, would that be an improvement, or detriment, to this forum?

I'm just askin'...

Bekologist

since you're askin'.......

i think the biggest improvement to this forum, mr head,would be if you just stopped posting altogther.

that's my opinion of course, but one likely shared by the majority of the posters to A&S.

anyhoo, let me check with the kids at the bike shop this week, and I'll get back to this confusing and puzzling topic for you, mr head.

Helmet Head

Bek, in order to be able to do something, you don't need to necessarily understand how or why it works. You do understand that a duck has no clue about the physics of how or why it flies, do you not?

Humans have the option of trying to understand. This is the basis for fields such as science and engineering, and those who are simply interested.

Helmet Head

(from the skills thread)

Maybe so. I'll try it.

You're saying that turning the bars right causes the bike to lean right? That makes no sense.
We do all this stuff without thinking about it, but when I do think about it, it seems like turning left causes a lean right, and turning right causes a lean left.

Are you sure you're not leaning right, and then turning right to keep the bike from falling too far in that direction? That's how it looks to me in the clip.

Edit: I looked at it again: the initial turn right at 3-4 seconds looks like it stops the lean/fall, not causes it.

Edit 2: In fact, you seem to turn right too far, thus starting to lean back left and so then you correct by turning left again. You do this twice in a row in that window between 3 and 5 seconds. You shift your weight, which causes the bike to lean, you turn into the lean, stop the falling, then turn back the other way.

Bekologist

how does a duck steer a bike?

let me ask the kids that too, head. this truly is a fascinating topic....

randya

I'm surprised HH didn't post a poll. This thread is in response to an argument he lost in the 'Bike Handling Skills' thread, check it out if you dare...

Helmet Head

Dude, I have not been arguing the necessity of the counter-steer with you. Why are you still arguing this?

As you're riding on the curb, you're constantly falling left and right, and constantly correcting for it to stay on the curb. As you fall right, you turn right; as you fall left, you turn left. At the moment before you pop off, you don't correct enough to stay on the curb (I presume intentionally, but it doesn't really matter).

Edit: Note how difficult it is to notice that the bike is falling/leaning in either direction, even when you're on the curb, yet how noticeable the turn of the bars/front-wheel is to control each minute fall/lean. This shows how little lean it takes, and explains why it's so hard to notice.

No, you're being sloppy with your reading.

I said a turn left causes [the bike to] lean right. Once you're in the turn (as Jobst is) you're long past needing to counter steer, and won't need to again, until you're ready to straighten out (assuming weight adjustment alone without counter-steer won't be enough).


The amount you need to shift your weight (lean), in order to get the bike to lean 'n turn, assuming you're over 100 lbs and the bike is 20-30, is very slight. That's why the counter-steer is not required. Try that on a 500 lbs. Harley. Good luck.

Bekologist

helmet head, don't despair, i'll be checking with any kids at the bike shop this week, and get some advice about this topic that's obviously confusing you.....

Helmet Head

No, this thread is in response to several requests in that thread to stop this discussion, because that thread was supposed to be about useful skills, and this was a theoretical discussion.

And how does one "lose" an argument where the only possible outcome is learning the truth?

Helmet Head

Pete,

Just got this from a friend, who looked at your clip:

Bekologist

are you posting about steering motorcycles or bicycles, mr. head?

can I get a heads up if is this thread is going to invoke any gorillas driving tractors or playing basketball?

Helmet Head

No, but that doesn't mean it's not happening.

What part of

Do you not understand?

Bekologist

I only actively countersteer when doing skid turns on ice or snow, Pete. I doubt HH has that turn in his repitoire.

Helmet Head

Been riding for 40 years, 1000 to 5000 miles per year for the last 35 years.
My commute for the last 7 years has been only 6 miles each way, and I don't ride every day, though I do when I can. Some days I work from home, other days I drive. On weekends I like to get a 50 mile ride in. I'm comfortable riding with guys who race in tight peloton formation and in rotating pacelines, if that means anything to you.

DannoXYZ 

You guys are actually both right but about different things. Slow-speed turning which doesn't generate lateral-acceleration forces (and you stay upright) is completely different from high-speed turns with leaning.

At high-speeds, there's two states in steering & turning. The first is the turn-in where you go from 0-degrees lean to whatever angle carves the radius you want. Then the 2nd stage is steady-state cornering where the lean is steady and the radius is fixed. Coming out of the corner is the reverse of the turn-in where you go from maximum lean-angle back up to 0-degrees.


Here, try this experiment...

1. find an empty parking lot where you can ride in a straight line for 10-15 seconds @ 10mph+ uninterrupted
2. start down the parking lot and take your left hand off the hoods
3. steady yourself so that you can ride with just your right hand on the right brake-hood in a straight line
4. push forward with your right hand and note the direction the bike leans and turns
5. repeat the experiment again with just your right hand on the brake-hood and.
6. pull back with your right hand and note the direction the bike leans and turns

Try this out on a motorcycle at 50mph+ and push/pull on the bars with just one hand and this experiment will really make sense (because the forces required to make it lean and turn is a lot higher, making the direction of the forces obvious).


Then, fill in the following form:

4. pushing forward with your right hand turns the wheel ___________ and the bike turns __________.


6. pulling back with your right hand turns the wheel ___________ and the bike turn __________.

unkchunk

I can't tell from the video clip. I thought the point of a counter steer before the main steer was just to get the bike leaning for the main steer. So if I were to turn left, I would turn the bike right for a moment to tilt the bike to the left, and then keep it leaning through the left turn. However I could just lean the bike to the left by moving my body and just simply steer left. Either way my center of gravity would be shifted to the left where the bike would be after the turn. I think having absolute zero tilt is too hard to achieve or to show. But how about this? Try leaning the bike to the right while making a left turn. I'll try it in the morning. I don't think it can be done.

DannoXYZ 

It's not about leaning one way and turning the other. It's about steering it one way and having the lean and turn go the other way.... Do the experiment I laid out above and see what happens..

gcl8a

Care to clarify (how a bike with locked, straight steerer turns)?

galen_52657

It won't

San Rensho 

Turning any in line, fixed rear wheel, steerable front wheel vehicle is done by countersteering, period. On a bicycle, it is very subtle and you don't realise you are doing it but that is how its done. Racers know this and use it to be able to go around corners fast. Look at a race and you don't see guys throwing thier weight around on a bike to make it lean and turn. Their upper bodies are perfectly still and then they are leaned over hard, all done by countersteering.

As others have said, try this on a motorcycle and you will immediately see that countersteering is how its done. You have to really wrench on the bars to get a moto to lean at 100 mph.

The reason most people tend to fall over when they first ride a bike is because counter steering is not intuitive. You think, if I want to turn right, turn the bars to the right. Wrong, fall over.

There was an experiment done on a motorcycle where a second set of bars was welded to the head tube. The normal bars were just loose, not locked in place. Nobody could get the bike to steer in any usable or predictable fashion using only the bars welded to the headtube.