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Old 07-09-2013, 05:49 PM   #783
Studly Adventurer
Joined: Nov 2008
Oddometer: 820

Turn loose, don't turn loose, I'm so confused.

Read this:!).aspx

This is an excerpt from the article: I think it explains a lot of things better than I have read previously, including my perception that the bike tends to right itself when releasing pressure coming out of a curve. It may be just a perception, but there are reasons why it feels that way.

......... Likewise, you need to steer the contact patches of a bike out from under it, so it falls, then arrest the fall by steering the contact patches to follow the top of the bike around the corner, then steer them even harder in the direction of travel than the top of the bike is going, in order to make the bike stand up again. It is often said that you recover from the lean by accelerating. Accelerating does widen your corner, thus making you go straighter. It does this by increasing the distance over which the sideways force of your lean acts. The physics adds up to the rule that a certain degree of lean, if you stay still on the bike, will result in a certain angular velocity (rate of directional change) at a certain forward speed. If you increase that speed by accelerating, it will not automatically change your degree of lean, but it will spread the force of the lean over a longer distance, thus diluting your ability to change direction, and you will go straighter. This is a natural and sensible thing to do when coming out of turns, but it is not sufficient to stand the bike up completely. It won't get the job done. You still need to finally steer the contact patch back under the bike.

Here's what acceleration in a corner does for you. It shifts weight to the rear, extending the fork, thus increasing rake and trail, which increases the self-correcting tendency of the steering. To the degree that you are leaning, this makes the bike stand up more. But it won't take you all the way, because that self-correcting force goes to zero as your lean goes to zero. Also, the faster you go, the more effective are your inputs to the handlebars, so it takes less and less motion of the bars to bring the contact patches under the bike the more you accelerate out of the turn. That reduces the trouble you need to go to in order to cancel the lean, but once again, you have to deliver that last nudge, to get the contact patches back under the center of gravity. Unfortunately, the contact patch takes more and more handlebar motion to steer, as speed approaches zero.


Center-stand screwed with this post 07-09-2013 at 06:02 PM
Center-stand is offline   Reply With Quote