Most of us love cornering on a motorcycle. Of course, we also prefer the curves to be on a fairly level road, gently banked in the right direction, and provide a clear line of sight all the way through. It's when any of those factors change that riders tend to start having more issues. In this post I want to concentrate on corners with elevation changes. In particular, when riding these curves downhill.
Given a choice I personally prefer to ride uphill on twisty roads rather than downhill. That's because physics does a lot of the work for me. When riding downhill I have to do that work myself. On the other hand, there are some roads I know where the curves with elevation drops are wickedly fun! Fun factor aside, we don't often have a choice. Roads turn right and roads turn left. Roads go uphill and roads go downhill. We need to know how to correctly deal with all of it.
Successfully negotiating downhill curves requires a more deliberate application of proper cornering techniques. In particular, setting a proper entry speed. Remember, a proper entry speed is one that allows the rider to roll on the throttle before leaning the bike and to maintain at least steady throttle application all the way through the corner. On the flip side, if a rider feels the need to roll off at any point in the turn, the entry speed was too fast.
I can't stress enough the importance of a proper visual lead for setting the proper entry speeds! It's what we see, or can't see, that sets up everything else.
It's the entry speed and throttle application that makes downhill cornering more difficult. Specifically, it's the fact that gravity is always working to make us go faster through the corner. Gravity is what makes going uphill so much easier. In this direction the pull is now on the back of the bike. Instead of working against us, gravity is now our friend. Have you ever found yourself able to use just the throttle for speed control on uphill corners? Hold onto that thought for a minute.
When entering a downhill turn the same requirements still apply. Slow enough before the corner to be able to maintain steady throttle. This is usually going to mean more slowing and less throttle. Notice that I used the word "slow" and not "brake". That's because braking is one way of slowing, but not the only way. The other method is engine compression.
Before we put all the pieces together it would be good to look at throttle application through a corner. Rolling on the throttle does more than accelerate us out of a curve. Judging by what I see, most riders think that's the only reason for using the throttle. This is evidenced by the fact that the majority of riders I see in our training classes want to brake late, coast into the corner, and don't roll on until the apex or later. There's so much more to it than that. Missing these other elements is a big factor in rider crashes.
Remember that rolling on the throttle lifts the bike. The reason for doing this before actually leaning the bike is to make maximum ground clearance available throughout the entire turn. Another advantage is that the bike's suspension is stable. All the bike is being asked to do is turn, not compensate between braking and throttle inputs while leaned over. Additionally, lifting the bike extends the suspension so that it can absorb mid-corner bumps. If the suspension is compressed these bumps will be more likely to throw the bike off the cornering line. Not a great thing.
In downhill turns, it also becomes very important to avoid unduly loading the front tire. We're already asking the tire to stick to the road during whatever degree of leaning we need to employ. Extra loading on the tire makes for a much smaller margin of error.
So how do we accomplish all this while still controlling speed in a downhill turn? Time to put all the pieces together.
Keep gravity in mind when setting the corner entry speed. This means braking sooner and/or more than when on level ground. Slow to a speed that allows the bike to gain a bit of momentum without putting us above the comfort threshold. Both ours and the bike's. Remember that the velocity gained due to gravity is going to be somewhat uncontrolled. Depending on the slope the entry speed will need to be greatly reduced. Always use both brakes. Apply the brakes and get off of them.
You will likely hear or read about using the rear brake in a corner to help control speed. Don't do it. Proper technique means not braking in a corner. Riding the rear brake opens the door to another kind of hazard.
When the bike is leaned over, a lot of the available traction is being used by the lean. This is true for both tires. Riding the rear brake requires traction. There is a finite amount of traction available at any given time. That traction needs to be split between side force, braking force, driving force and traction reserve. Using traction in one place takes away from the traction available for the other needs.
The particular hazard when trailing rear brake while leaned over is that any sliding of the tire will happen in a sideways direction. Usually towards the outside of the turn. Which means the chances of a low-side crash are increased. Here's another thing to be aware of. When the rear tire is near the limits of traction any side to side movement of the rider can be enough to push the tire over the edge, so to speak. Best not go there.
Be prudent when applying the throttle. Remember that the throttle only has to come back up to "steady", not "increasing" for the requirements to be met. Less throttle means less speed gained in the corner.
Ok, I know this sounds like a lot of work. Heavy braking, gain speed, brake heavily to set up for the next curve. Hey, you do what you need to do. Or else. One might wonder, though, if there is a better way. Now that you've asked, let me offer some food for thought that might help smooth things out.
Remember me writing previously about using the throttle as a rheostat? In other words, like a dimmer switch on a light. Bluekat will recognize the last couple of photos. I went out and rode some corners on a road she rides reqularly. I also rode some others, like in the first photo. Notice there is a huge downhill slope in the first photo. By the way, I see on her blog that she is now riding Parish Gap. Great road. In case you hadn't noticed, yet, Kari, all the blind corners go the same direction depending on which direction you ride. From Turner southbound, they all go right. You still need to be aware of limited sight distance, but it's nice to know which way the road goes!
Anyway, another key is to gear down. In the corners above I found third gear to be effective. Using engine compression to both slow for a corner and control speed during the turn makes things very smooth. I find that I have to use the actual brakes much less. The engine might make a bit more noise than you're used to. Don't worry. Here's a little secret. Bike motors like it!
As a side note, if a rider is worried about going wide on a downhill corner use a late apex. Nobody says you have to apex in the middle of a turn. If you can't see the exit of the turn, stay wide until you can see it. This means a late apex. Even if you can see the exit early, a late apex will tuck the bike back into the lane. Early apex equals a wide path of travel. A late apex tucks you back in.
Here's to many fun and safe corners in your future!
Miles and smiles,