Great! An explanation. I knew this effect was so pronounced that someone would know about it. So it is really just as simple as trail. I guess this is why we need the side wind pushing on the bike frame and not the front wheel its self? So full streamliners that are having trouble with sidewinds can increase trail to get more self correction at the expense of having slower and heavier steering transitions in chicanes? I have seen photos of land speed bikes with the front, top, quarter of the front wheel fully faired and the back half fully open. Does this help to force the counter steering movement in a side wind or is it just for the aerodynamics?
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Originally Posted by Ken Fry
Good description.
Yes, most bikes are self-correcting. A gust causes the steering axis to translate away from the wind side. (The gyro effect of the rear wheel tends to restrain the bike's rolling more than it prevents the frame from yawing, because of the leverages involved. The frame yaws, and the steering head translates.) The contact patch, due to trail, is behind the extension of the steering axis. Therefore, in a crosswind from the left, the steering axis moves slightly to the right. The contact patch is then slightly to the left of the steering axis, meaning that the bike is steering itself to the right. This banks the bike to the left, into the crosswind.
You can take your hands off the bars entirely, and this feature works just fine (provided you don't have a bike prone to tank slappers)
If you really freeze your muscles and clamp onto the handlebars with a death grip, you can defeat this built-in trait. Taking the weight off the grips by tucking and putting your chest on the tank makes the effect more pronounced.
On some bikes, cranking in a lot of steering damper will interfere with this self- correction, and the bike will tend to wander.
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