Thursday, April 29, 2010

Motorcycle Cornering 101


NOTE: This is a basic introduction to cornering, geared toward touring and cruising riders. It's from personal experience and racing techniques, but there won't be any dragging knees and such. Your mileage may vary, get a second opinion, and all that.

Keeping it simple
Every curve is different so each approach will be different. Right-hand vs. left-hand, banked vs. off-camber, increasing radius vs. decreasing radius vs. hairpin, sightline obstructed, slippery surface, etc. etc. This will be a discussion with generalities, to keep it brief and to keep it at the 101 level of cornering skills. More in-depth discussion for the layman and beginning racer can be had by reading Nick Ienatsch's "Sport Riding Techniques." Great book.

Don't ride beyond your skill level
A leading cause of solo motorcycle accidents is from riders going into curves "too hot" and quickly running out of room, possibly head-on into a vehicle (right hand turn), or ending up in a tree (left hand turn). This can be caused by a number of factors including: overconfidence, riding and trying to keep up with more skilled riders, or lapses in concentration.

Ride slower until you build your confidence. The speed will follow.

Approaching the corner
When approaching a right hand corner, position the bike as close to the centerline as practical. A left hand corner should be approached as close to the shoulder as practical. See the drawings above.

Braking should be done before the corner, while the bike is upright. Use mostly (or exclusively) the front brake. You have an option of using a light rear brake through the rest of the curve, to stabilize the bike. That's called "trail braking." Just starting out, though, use the front brake until you start leaning into the curve.

Apexing
Late-apexing is important for a number of reasons: 1) It gives more time in a straight line to perform the braking, 2) It allows a faster entry speed, 3) It allows you to see further around the corner to look for obstacles, slippery surfaces, or a decreasing-radius situation.

Note that late-apexing means you don't make a perfect arc around a corner. See the drawings above.

Body positioning
This is where tourers and cruisers can use some help, especially after having their butts firmly planted in a comfy saddle. You don't need to be "hanging off," but try shifting your weight so one butt cheek is off the seat towards the inside of the corner. What helps getting used to that is to stand on the pegs or floorboards every once in a while. Then shake that booty.

When approaching and braking for the curve, your body should go into "attack mode." Knees gripping the tank, body pitched slightly forward and tensed against any front fork compression that may happen. The back shouldn't be ramrod straight, but shoulders should be loose and rounded to allow more flexibility.

Slow things down for a minute. Once you've scrubbed off enough speed for the rest of the turn, let off the front brake, weight the inside peg, push the tank with the outside leg, and rotate the body so the inside shoulder points toward the exit. If anything, remember this: ENTER THE TURN LEADING WITH THE INSIDE SHOULDER. At the same time scoot your butt cheek off the seat, toward the inside of the corner. Now freeze it.

Right now, your body should be starting to lean into the corner but the bike is still upright. Continuing to rotate the body will push the inside grip causing the countersteering, which will cause the bike to lean over. Freeze it again.

All through the corner, your head should be positioned so your eyes are even with the horizon. This maintains your orientation so everything keeps a visual consistency.

Look where you want to go
Look around the corner as far as you can. Don't look at that tree because you'll run into it. If someone crashes in front of you, you should still be looking around the corner. I've seen more racers follow the tracks of a crasher in front of them because they stopped focusing on where they should be going. Don't get distracted, get through the curve first.

In a hairpin, focus as far as you can around the turn and shift the focus as you continue through the turn.

If you're in aggressive mode, your inside knee would be pointing away from the bike, towards the ground; your head and shoulders will be pitched forward near the inside grip, but where would is the bike now? Yes, it's leaned over, but not as far as you. Why is that the optimum position?

Because you don't want to be scraping parts. Scraping parts is a sign you're about to lose traction and low-siding...not good. So the important thing to remember is for YOU to lean first, and then the bike. Some people think dragging parts means they're pushing the envelope, but often they're just pushing the bike down rather than preserving the bike's lean angle.

The bike should come closest to the inside of the curve about 2/3rds of the way around the curve. That's the (late) apex.

Exiting
As soon as you apex the corner, you should be on the gas out of the corner. Shift the weight back onto the seat, still in "attack mode," and accelerate away towards the centerline (right hand corner), or towards the shoulder (left hand corner). The right amount of acceleration will provide the rear wheel traction to keep you from low-siding.

All the movements described so far should be as smooth as possible. Remember that the throttle isn't an on-off switch, but more like a rheostat. Braking should be smooth, as well.

Prepare for the next corner.

Some hiccups
When encountering obstacles or slippery surfaces or a rapidly decreasing radius or coming in too hot, you may have to (quickly) abandon your awesome technique, upright the bike, and get on the brakes again. Don't use the front brake while leaned over!

Off-camber curves mean sacrificing lean angle, so keep that in mind when you see them. Body positioning should be more exaggerated in an off-camber corner.

Blind curves mean later apexing so you can see further around the corner.

Practice
Rather than trying anything to keep up with faster riders, concentrate on your technique and maybe you'll be outpacing them soon. Invest in Ienatsch's book, sign up for some trackdays, have fun.

Ride safe!

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