Ok--there have been a lot of posts lately--myself included, discussing Sheldon Brown's advice.
I find his info to be very useful. However, i am rather confused about his advice re: cornering. He says teh best way to corner or turn is to lean both the bike and the rider towards the turn. He disfavors a) keepign the bike level and havign the rider lean and b) doing a motorcross move and leaning the bike whilst keeping the ride upright.
I tend to follow the last option. All the times I try leaning in with my bike (per his advice) my back tire slides out and I crash. Is his advice wrong, or am i doing something wrong?
You got me really thinking of my riding style. I know for certain sections of this one trail, I'll slide my tire on purpose through the turn... be it by position or by doing a "kick out". And there are certain sections of trails or even my commute that leaning both bike and body would be a very, very bad thing.
I really think your lean technique would depend on the speed/circumstance.
As for your question though, I think your speed, and tire pressure would come into play here.
Technique on trails is different, but on the road, do as the motorcycle does. You want to keep your center of gravity lined up with the bike. Leaning the bike a lot but keeping yourself level doesn't help you turn, it just helps you lean. Novice motorcycle racers do this too, because dragging a knee is 'cool', and they assume that the farther the bike is leaning, the faster it is turning. Of course, dragging a knee alone doesn't help you turn, because the forces from your body aren't contributing to stability, and hence aren't contributing to your ability to make a tighter turn. While the novice is dropping the bike to the side and holding his body up so he can drag a knee on the inside line, the expert is holding his body close to the motorcycle and passing him on the outside.
You and your bike are one machine, if you lean yourself with it, your body weight will contribute to the squishing of your contact patch, and you'll stay more stable. You'll end up leaning less for the same speed of turn, which also adds to stability.
You have to trust the traction. Its a hard lesson to learn, and you really have to train your body to stay with the bike. On my tall bike you have to leeeeaaann to turn. The angle is the same as on a regular bike, but you are so high up that you end up feeling like you are tilting way beyond safety, but if you hold the line and trust the physics, you come around the corner safe and sound.