Handling Curves: A Better Line

James R. Davis © The Master Strategy Group

Taking curves is rather a personal choice in terms of selection of entry and exit points as well as speed.  The typical advice is to choose an entry point that allows you to make the curving the smoothest line through it so that you always have the least lean demand.

This, of course, gives you the most ability to compensate your path through he curve should you find a need to do so. It also means that you hit the apex of the curve at about its middle.  That is, you enter from the outside edge of the curve, then move towards the inside until you reach its apex, then continue from there outwards until you are once again at the outside of the curve just as you exit it.

My alternative is to delay the entry into the curve. That is, to stay to the outside edge well past the normal entry point, then turn much more sharply into it and hit the inside much beyond the normal apex.

This gives two significant advantages over the ‘smoothest’ course:

1. I get the lean that I enjoy in the beginning of the curve where I have seen all that I need to see in terms of potential trouble.

2. When I exit the turn I am traveling at a much reduced angle relative to the path of the road. That is, since I am closer to the end of the curve when I reach the inside than is the normal apex, I have fewer degrees of the arc left to go before I am again going in a straight line. Said differently, if the road changes directions by a matter of 90 degrees through a curve, no matter what path you select through it you will have totaled 90 degrees when you are out of it.  Since I turn more into the curve at my delayed entry point, I have less left to go to complete the turn when I am near the exit.

This last advantage is of profound importance. It gives far more ability to handle unexpected problems as you get closer to the end of the curve. 

For example, what if it turns out to be a decreasing radius curve after all, or if there is gravel in the road that was not visible at its entry? By the way, when I said that ‘I stay to the outside edge’ above I in no way meant to imply that I get close to the line. Far too many people seem to think that they have performed a safe maneuver through a curve so long as their wheels do not touch or cross the (center) line. Wrong! If any part of your motorcycle crosses that line, including just a grip, you are in the path of oncoming traffic, and are in their lane.

In any event, I try to overshoot my entry to a curve. Then I aggressively push-steer into it, and delay reaching the inside of the curve well past its apex. This, incidentally, allows me to start an aggressive roll-on of my throttle sooner than when I am at the inside of the curve which gives me a better handling bike through the majority of it.

I should add that this delayed entry approach requires that you get in the habit of not entering the curve too fast. Further, the right approach speed is one that requires no braking at entry. (You should use modest throttle roll-on all the way through any curve. The ‘roll-on point’ is where you can go after a higher exit speed if you happen to be aggressive with your bike). If you find that you cross the outside line, ever, then it is time to reassess what you are doing.

Approaching the curve too fast? Insufficient confidence to aggressively push-steer when you need to? Insufficient experience to pick a good line? Lack of respect for the laws of chance (one of those times a 4-wheeler will have two of them across the line)? Acting like riding with friends is a competitive sport? Whatever it is, if you ever cross that centerline you are riding above your abilities (and everyone around you will know it) and you need to change something soonest. Otherwise, make sure your friends know your intentions for the donation of your organs.

This method is just my preference, after all, and it seems to me is generally safer than the ‘smoothest line’ method usually described.

Braking in a curve … of course you can!

James R. Davis ©The Master Strategy Group

You should establish your entry speed before you enter the curve.

That is, you have to eliminate all excess approach speed, with braking if necessary, while still traveling in a straight line and while the bike is vertical. You should ‘set’ your suspension before you enter the curve. That is, you should not have to deal with a changing center of gravity that results from weight shifts generated by changes of acceleration or braking while in a curve. You should have already established your entry speed at this point so your springs/shocks are resting at normal riding positions. But because you want maximum control of your bike through the turn, you want your front tire to be able to handle modest bumps and surface distortions without destabilizing your bike so you want to shift some weight to the rear tire. That increases rear tire traction, loads the rear shocks/springs somewhat more than the front, and increases over steer. Moreover, you want that attitude all the way through the curve so you maintain a modest acceleration all the way through it. All of which sounds like you should accelerate all the way through a curve.

However, not if you are on a decline.

To begin with, you know that you must lean the bike in order to make a turn. That the faster you go through a given turn, the greater the lean that must be used. Clearly, you can accelerate to a speed that is beyond your ability to negotiate a turn.

Thus, if you modestly accelerate all the way through a turn it must be that you established a low enough entry speed to allow it, and that you did not use excessive acceleration through the turn. Next, by virtue of being on a decline, you will accelerate without any throttle at all. If the rate of acceleration is high enough, there is no safe entry speed that would allow you to complete the turn safely (without some braking.) Because you are on a decline, there is already more weight on the front tire than you can safely shift to the rear via acceleration to give you the handling stability that is sought from acceleration without exceeding your ability to negotiate the turn. Finally, because you are in a turn you are, by definition, already accelerating! (Delta V - any change in velocity is acceleration - even if you are slowing down) Your shocks receive increased loading just because you are in a curve - from centrifugal force.

If you are on a decline while in a curve, you should not use your throttle to accelerate. Instead, you should use your brakes and/or engine braking either to maintain your entry speed or to allow only modest increases of speed. At the same time, you should have moved back as far as possible in your seat to shift weight to the rear tire.

… If you use yours brakes while in a curve to stop you should gradually straighten the bike up as speed decreases and gradually increase brake pressure until the bike is vertical. That remains completely true. If you are not slowing but merely maintaining your speed, then there is no straightening of the bike required

…Of course you can use your brakes in a curve. Brakes are not used merely to stop your bike, they are used to offset acceleration (i.e., to either slow the bike or to prevent it from accelerating as fast as it otherwise would go from gravity assist.)

Finally, if the decline/curve is long enough you should rely heavily on engine braking rather than just your brakes in order to keep your brakes functional (not overheated) should you need them.