In a typical blind turn, your...
In a typical blind turn, your line of sight is limited by the obstruction that the turn was built around. A conventional line around the corner with a tight apex will restrict how far around the corner you can see, leaving you less time to react to debris on the road or oncoming traffic in your lane.
Most sportbike riders will list blind corners as their least favorite part of a twisty road, and with good reason. Quite often danger lurks where it can't be seen until it's too late to react, with gravel or an oncoming car in your lane. Just the surprise of that danger suddenly coming into your sight can sometimes be enough to cause you to make a mistake, when you would normally be able to deal with the situation easily. This can cause anxiety in many riders, making a bad situation worse. Navigate a blind turn ready to deal with whatever may be ahead, however, and you'll be able to minimize that anxiety and be more confident. Roads end up twisty mostly because they were built to go around things like hillsides and trees, and those objects usually end up making it impossible to see around the corner. Less often, turns are placed at the crest of a hill, again making it impossible to see. The two types of blind corners each require a different approach to minimize the chance of trouble.
As we mentioned in a previous Riding Skills Series ("Lane Position", June '09), it's worth pointing out again that curving roads often follow the side of a hill, with the majority of the obstructions that make the turns blind on the uphill side of the road and a drop on the other side. Travel in the direction that keeps the hillside to your right, and the right-hand turns will be blind with the obstruction directly to the side of the road. Travel in the opposite direction, with the hillside to your left, and now you've got an extra lane between you and the hillside, offering a buffer zone in most of the blind turns, which lets you see farther around each turn. This means the road is generally safer - and less frustrating - travelled in one direction than the other, and you can make a ride more enjoyable by planning the route accordingly. A prime example of this is the Pacific Coast Highway, which in many spots hangs on the side of the mountain jutting out of the ocean. Heading north on this road, you will encounter many blind turns while the southbound trip is somewhat easier.
Keeping a wide line through...
Keeping a wide line through the first part of the turn will allow you to see as far as possible. This does, however, leave you exposed to other dangers, especially in right-hand corners; keep your speed down enough so you can tighten your arc if necessary. Once you can see the exit, return to a conventional line for the remainder of the turn.
In a turn that is blind due to something blocking your view, keep a wide entry to maximize how far around the corner you can see. While a wide entry does leave you open to additional dangers should the radius of the corner tighten or you come upon debris in the turn, the benefits of being able to see farther around the corner - giving you more time to react to a situation - outweigh these downsides. Keeping your speed down will allow you to tighten your line if necessary, as well as giving you even more time in hand. This is one situation in which you'll have practically no choice but to look closer to your front wheel and not a distance down the road as you would normally. Let more of your attention be drawn to a point however far that you can see, so that you are ready to react immediately upon seeing something around the corner. If something unexpected does appear, don't let your focus be shifted away from where you are going. When the exit of the turn is apparent and your lane is clear of debris or oncoming traffic, it's safe to arc in to an apex and finish the corner.
While a left-hand blind turn...
While a left-hand blind turn restricts your view less than a right-hand bend and allows you to take more of a conventional line, be especially wary of tightening your line to the point that your head may be over the center line.
The same hillside that makes a turn blind is often the source of gravel in that turn; likewise, the same trees that make a turn blind usually drop leaves or moisture on the road. A blind turn and a slippery surface often go together. This is where things can get tricky as with a wide line you don't have much room to straighten up and ride directly over something. The upside is that the wide line has let you see the slippery bit earlier than you would have otherwise and given you time to adjust your line. When you do come upon gravel or something slippery on the road, momentarily tighten your line and arc toward the inside of the corner. It may seem counterintuitive, but this will give you room to then straighten up and ride directly over the obstacle. Another danger in right-hand turns is that a wide entry leaves you more exposed to an oncoming car or bike that may be partly in your lane. The same applies to oncoming traffic as it does to gravel in the road: You should be going slow enough that you can momentarily tighten your arc to give you as much room as possible, then when the traffic is past return to your planned line.
Once you've gone down a particular road a few times, you'll be familiar with the blind turns and know a bit more what to expect. You'll know which turns are typically dirty or clean, and which corners tighten up. It's best to keep using that wide line on the left-hand turns, leaving you extra room should a car or bike be coming over the center line, but in right-handers a more conventional line and slightly tighter entry will give you more of a buffer to that oncoming traffic. Still, keep your speed down in case there is something unexpected to maneuver around.
Blind turns cause anxiety...
Blind turns cause anxiety because you want to look far down the road but can't, and this confuses your brain much as this picture does. Focus more than you would normally on what you can see, so that you are ready to react immediately to debris or oncoming traffic in your lane.
By far the majority of blind turns on the street are that way due to an obstruction that you can't see around. Occurring less frequently are corners made blind by the crest of a hill, and these are tackled in a slightly different manner. Your lane position has no effect on how far around the corner you can see, so keeping a wide entry doesn't help in that regard. In these situations the general rule is keep to the right, leaving as much of a buffer as possible to oncoming traffic. In left-hand turns this means the same approach and reduced speed as used in a turn made blind by an obstruction. In right-hand turns, keeping far to the right leaves you better positioned to simply straighten up over debris in the road as well as being less exposed to oncoming traffic. It may seem a lot to keep track of for the different turns, but thankfully much of your entry line will be intuitive, and you'll find yourself gravitating to the correct spot and slowing down the necessary amount anytime you can't see where you're going.
More than anything, it's the surprise of a car or patch of gravel suddenly appearing that can cause the most grief in a blind turn, especially with inexperienced riders. The shock can easily upset your concentration when you need it most. We've seen riders spooked by an oncoming car enough that they bobbled, straightened up and ran right off the road - luckily missing the car. In any blind turn, keep focused on where you're going, be ready for whatever may be on the other side of the turn, and have some speed and room in hand to account for it.