Originally Posted by
livedarklions
That article can't be correct, if it were, no one could turn no-handed or steer a unicycle. It states a bunch of stuff that makes that possible is impossible. All due respect to the author, but that's reason enough for me to reject everything that follows from those assertions.
Sometimes the easiest way to understand the importance of something is to "break" it. I recently rode with an unbalanced load on my rear rack. You become very aware of how much lean initiates a turn when you have to do it differently than normal.
No one's arguing hands play no role, I just find all this "this is how everyone steers" stuff simplistic, and based on assertions that are obviously over-broad. If I'm initiating my turns with a countersteer, I have yet been unable to detect it. I'm not finding these "you must be" assertions to be based on anything other than the axiomatic assertions of people who have been trained in a particular technique. I'm also aware that I perform different kinds of turns in drastically different ways.
People are sitting differently on the bike, using completely different styles of handlebars and frames, riding at all sorts of different speeds, on all kinds of different surfaces, with drastically different tire widths, and with different attitudes towards maintaining speed through the turn. Any assumption that they are all employing the same turn technique for every turn is just implausible.
Getting back to the topic of the OP, obviously stem length and handlebar width affect the effort needed to turn the wheel, but the effects on posture also affect distribution of your body weight.
Yes, frame geometry and the rider posture have their effect on the bike handling. But the base mechanism is the same.
Unicycle is a good question, we will need to do some research to find out.
Originally Posted by
Trakhak
Those of you who are skillful enough to be able to walk next to your bike and steer it by holding the saddle can easily demonstrate that countersteering is unnecessary. Lean the bike to the left, and the bike turns to the left. Lean it to the right, and it turns right.
This is a different setup as your feet are touching the ground, and additional (as opposed to wheels only) forces/torques are applied via the feet.
Originally Posted by
terrymorse
But while not obvious, that is the way leaning works to steer a bike.
If you're balanced and going straight on a bike, you can't simply lean your body to the left without having the bike simultaneously lean to the right.
Here's the sequence:
0. bike+rider balanced going straight
1. rider leans torso to left
2. bike leans to right
3. bike steers to right, contact patch moves right
4. bike leans to left
5. bike steers to left
6. bike+rider now balanced in left turn
To those who say "but I can lean one way without having the bike lean the other way". Freshman physics says "no, you can't".
Exactly. And if we assume that the wheel in step 3 turns under the weight of the wheel + fork + handlebars, the responsiveness of this turn depends on the front geometry. Does it explain why the rando bikes need front load to handle better?
Coming back to that v^2/r formula, at large speed a small turn of the front wheel has larger effect, and it can easily lead to a fall. There is a video by GCN saying that responsive steering is desirable at a small speed and less responsive steering is desirable at a large speed: