Staying light on the bars
Light on the Bars - What does it mean?
or Your steering head is suspension, too.
We've all heard it before... someone giving friendly advice, and they say "It really helps to be light on the bars" or to "keep your weight off the bars" or "support yourself with your back". OK, we say, and head out riding again, with a vague idea of what to try.
Well, light compared to what? Light... but still some? How can I keep my weight off the bars and still control them? Questions abound.
Starting with some quick physics background for this discussion is probably a good idea, specifically the front end suspension of the motorcycle. We all know the basics of how forks work... they absorb some of the energy from bumps in the road by compressing and extending, allowing the motorcycle to "ride above" the imperfections. This works great while you are going in a straight line, but as soon as you lean the bike the directions of the forces involved change. When you're leaned over and you hit a vertical bump, not only does your suspension want to compress, it also wants to flex towards the "high side" of the motorcycle. If you are in a left hand turn and hit a bump, the forks will want to flex slightly to the right and vice-versa. This reduces the efficiency of the suspension action because not only does metal not like to bend sideways like that, but it also starts to bind up the normal up-and-down sliding movement of your forks, making that more difficult as well.
Most manufacturers nowadays are allowing for some flex in the steering head/upper frame section to allow easier motion left and right. This shows how much of an effect this has on handling. But does that mean there is nothing we can do about it? Not at all. In fact, we as riders can help out a lot just by doing that simple act of being "light on the bars."
There is one more movable part of the "suspension" in the front end that does allow for side to side motion. It's the steering head assembly. When you are leaned over, vertical motions in the roadway (bumps) can be absorbed by the steering action in the front end of your bike. To get a good picture of this, hold your hand out with your fingers pointing ahead and your wrist turned so your palm is facing either left or right, depending on which hand you picked. Put it on a table, like it is a wheel rolling along. Now, make turning motions (moving your fingers left and right, using the base of your pinky/palm area as a pivot point, and moving your wrist opposite of your fingers.) Now, lay your hand down aways... get some lean angle on it. Try making the same motions again. You'll notice that the tip of your pinky and the base of your palm get closer and further away from the table as you do this.
So, when you are leaned over on your bike, you have two movements to absorb vertical bumps - the fork action and the steering action. The further you lean over, the more the steering action accomplishes, and the less the fork action accomplishes, because the more you lean, the more vertical the steering action becomes and the more horizontal the fork action becomes.
"But doesn't that change my line through the corner, since I'm letting the bike steer?" Yes and no. Yes, for the briefest moment, it does. But almost immediately (depending mostly on how much your front wheel weighs, and how fast it is spinning) it will be pulled back into alignment by the gyroscopic effect. So, it doesn't noticeably affect your line in the long term.
Imagine if you took a solid metal bar and welded it to your triple clamp or handlebars and welded the other end to your frame. Now, you have no side-to-side motion, and you lose out on a big chunk of your suspension action. The more you lean, the more you lose. This is essentially what happens when you ride with a "death grip", or if you are trying to "muscle the bike" all the time. This is what needs to be fixed, and it's fairly easy, because you need to do less. Quit holding on as tightly.
Ahh, but I hear you asking... "I can't let go, the throttle and brakes are there, and besides, I need to be able to steer." Valid point, and here is where the hard part comes in. In order to allow the handlebars the maximum amount of shake/shimmy to absorb bumps, you need to control the bars with as little energy as possible. This is where we need to quantify things to make it worthwhile.
You only want to control the bars as much as you have to.
Obviously, when you make your turn input you have to control the bars. A simple push on the bars to set your lean angle and then you are done. The next thing you are supposed to do is roll on throttle, smoothly and continuously through the corner. Again, you have to control the bar, but not as much as many people think. It only takes 1 finger and a thumb to roll on throttle, once your line is set correctly. It is very common for experienced riders to go through corners rolling on the throttle with 2 digits on the right hand and not touching the left bar.
As long as you are rolling on the throttle smoothly and consistently your motorcycle will be stable. If your motorcycle is stable, you can leave it alone. If you leave it alone, it will do what it does best... track a tight line through a corner. When the bike is tracking well, with minimal input from the rider, those shakes and shimmies from bumps in the road will be over before you notice they happen, because you are allowing the suspension to do its job - keeping the chassis, and what it is supporting, stable.
You only need to control the bars when you want to change something. Would you reach down and try to keep your forks from sliding up and down? Then make sure that you are letting the bars move when they want to, too.
Staying light while braking is a much more difficult task, because everything you are doing is pushing you into the handlebars. It takes a lot more back and leg muscles to keep your weight off the bars. Many times it's just not possible. Just do the best you can, remembering that the more effort you make to keep your weight off the bars, the better the bike will feel.
"So, how can I tell if I have too much weight on the bars?" A couple ways, actually. The easiest way is to slowly take your left hand off the handlebar until it is just hovering over the bar. If you have to change your body position to do this, or if the bike starts to track to one direction or another, chances are very high that you had weight on the handlebars. Another thing that can clue you in is if your bike feels "iffy" or "sketchy" or "about to wash" or most any of those bad feelings that you can really nail down (like the bike is pogo-ing from a bad shock). This may take some time to feel out, as you have to feel it when it is "good" to know when it is "bad".
A lot is trial and error. There is no substitute for experience. Experiment. Does it feel better going through a corner like this, or like this? Just remember... "Stay Light On The Bars."