??how do you deal with downhill decreasing radius turns?/

[He Man]

First time i went down, i was bit by one, and i rarely ever see them, but how are you suppose to deal with downhill decreasing radius turns? what line are you suppose to take?

[Raux]

First time i went down, i was bit by one, and i rarely ever see them, but how are you suppose to deal with downhill decreasing radius turns? what line are you suppose to take?

a slow one

[somegirl]

I'm no expert, but I take this left-hand decreasing radius downhill turn every day.  It's probably the most deceiving corner on our road, people bite it there frequently.

Hopefully the green line here gives you some idea despite my poor drawing skills.



Coming into it, I stay well to the outside of the turn (right part of the lane) and brake hard into a late apex.

I then turn, staying to the outside of the turn and keep it slow as Raux says, watching the vanishing point to set my speed.  I often continue to lightly drag the front brake during the early part of the turn (note this is not the same as suddenly braking in the middle of the turn).  In the later part of the turn I either coast or have the throttle just cracked.

I wait until I can clearly see the exit then I start to straighten up and increase throttle at which point I can move more to the center of the lane (setting up for the next turn which is a right-hander).

On a right-hander I would do something similar but I wouldn't be as far to the outside of the turn because I don't like being too close to the double yellow (too much risk of an oncoming car drifting over the DY), so I'd be more in the middle of the lane rather than the left-hand side of the lane.

BTW I do exactly the same thing on a bicycle except I start pedaling instead of increasing throttle.

[EvilSteve]

On the street pretty much how somegirl put it, late apex, slow entry speed. Whenever you approach a corner you don't know, you should always at least consider the possibility that it's a decreasing radius corner & lower your entry speed accordingly. You *can* use your rear and trail in to help tighten your line but this isn't recommended when you're hitting a downhill decreasing radius for the first time. Practice before you use it.

On a track, you'll know the corner & can set your entry speed higher because you know what to expect. On the picture that somegirl put up, it's a pretty long decreasing radius corner so on the track you could try a line that means cutting the corner on the way in and turning in much later. Kind of like a double apex corner line.

The problem that you'll have on the street is that even if you judge the corner correctly and your entry speed is good, there are lots of variables like road surface, wind, traffic, etc that can not only throw the bike off but throw you off mentally as well. This is why something like a decreasing radius (and blind in the case of somegirl's picture) is something we should all treat with a great deal of caution.

For the record, I love decreasing radius corners, really easy to get your knee down (if you know the corner!) and, in fact, I first got my knee down on the track on a decreasing radius corner. Once you add the down hill factor and the fact that it's a public road, make sure you take it back a couple of notches more than you normally would at least until you learn the corner.

To sum up I'll quote Raux: "a slow one".

[somegirl]

I'll add that if you are worried about picking up too much momentum because of the downhill, you can downshift before starting the turn.

Your engine braking will keep your speed in check.

[EvilSteve]

Unless you have an APTC (which He Man does), in which case the engine braking will be less useful. But engine braking is much like using your rear brake anyway.

[Buckethead]

That was how I went down last May. They still give me the willies.

If I'm on a new road, but following someone who knows them, I try to imitate their line. Doesn't work too well if you're riding in staggered formation, but I hate riding like that anyway. I'll add the obligatory "ride your own ride."

Otherwise, I try to delay my turn in point a bit past where it feels like it should be, and make sure I look hard through the turn. My natural tendency in those situations is to kind of hug the centerline which, as we all know, is counterproductive, and I have to fight it like mad.

On those occasions when I feel I need to tighten my line, I try to drop my inside shoulder. If I need even more, I can still stick my knee out, but I typically don't ride at speeds where I need that much correction.

For most situations, I've found that, of all things, the posted speed limit is usually a good bet on unfamiliar roads. Who'd a thought?

[Cider]

I trail brakes until I'm happy with my speed.  If I get scared, then I consider that a warning that I took the corner too fast and need to check myself.  I do my best to run nice lines on the street, but I don't sweat it too much.  The street has so many variables that the ideal line is always changing.

[Holden]

Biggest thing is turning your head more. Easy to forget and you end up looking at the side of the road. Neck like owl.

[fasterblkduc]

Coming into it, I stay well to the outside of the turn (right part of the lane) and brake hard into a late apex.

I then turn, staying to the outside of the turn

  How do you manage to late apex a turn, and then turn in The apex of a turn is the point at which you are the closest to the inside of the turn and you don't get to the apex until you have completed more than 50% of the turn.

The answer is what Raux said...slow. You are on a public street so you don't have much of a line choice. You can't use the entire pavement. If you could, then there would be a choice. People can talk all day about their favorite decreasing radius corner and how they like to ride it but every corner is different so what works for one will not always work for another. The examples given are good for when you know the turn and are prepared. I'm guessing from your question that you were surprised by a turn and panicked.
If you come up on a decreasing radius turn by surprise, There are some things that you should NOT do.

Don't grab the brakes, (especially rear) If you do, just ease on the front smoothly to scrub off a little speed. leaning over and using the rear brake is a bad combination that can very easily cause you to lose traction with the rear.
Don't stand up and ride off the turn. You don't know what is off the pavement and you are now in uncharted and dangerous territory.
Don't panic and just drop the bike.

Just stay committed and turn the bike in more. Your bike can do it and if you always practice good form, and smooth inputs, then you can ride it out just fine. Part of that good form is what Holden mentioned...look through the turn as far as you can. Also, body positioning, smooth braking and throttle inputs, and knowing the limits of your bike, and yourself are key.
If you are able to take a performance riding school like Parks, Code, Schwantz, etc. you will gain extremely valuable info and break down some of your bad habits that you form on the street. Then you are better prepared for, and have better skill to help with situations like these.
I am a Lead instructor at one of these schools and I can tell you that what you gain is priceless. My favorite thing is seeing the amazing progression from my students from the beginning to the end of the day.

So, the best way to take that turn or any other turn is to be as prepared as you can be. Educating yourself by taking a school is the best way to accomplish that. If you have specific questions and want some advice, feel free to pm me. 
 

[somegirl]

How do you manage to late apex a turn, and then turn in The apex of a turn is the point at which you are the closest to the inside of the turn and you don't get to the apex until you have completed more than 50% of the turn.

I guess I used incorrect terminology...how about: I brake hard into a line that uses a late apex.

[He Man]

Unless you have an APTC (which He Man does), in which case the engine braking will be less useful. But engine braking is much like using your rear brake anyway.

no APTC here. Dry clutch! 

I forgot where i read this or who told me, but am I right to say that the biggest danger in a decreasing radius turn is having to turn the bike more than you intially thought, and usually very dangerous because you carried entry speed for corner radius A not B? It would be nice to find a corner to practice on but i only know of 2 dec radius turns. 1 bite me, the other has to many cars on it.

[fasterblkduc]

I guess I used incorrect terminology...how about: I brake hard into a line that uses a late apex.

I wasn't trying to bust your chops...hard to convey emotion on the internet. That does sound better. Would you say that a better way to explain your braking would be to trail brake? Because I think what you mean is that you are staying on the brake longer into the corner to scrub off more speed. For the less experienced riders, hearing "brake hard" can be a little confusing.
Just some food for thought

[fasterblkduc]

no APTC here. Dry clutch! 

I forgot where i read this or who told me, but am I right to say that the biggest danger in a decreasing radius turn is having to turn the bike more than you intially thought, and usually very dangerous because you carried entry speed for corner radius A not B?

Yes. But if you are as prepared as you can be and have had lots of practice with advanced techniques, then you can usually manage to pull it off without crashing. More specifically, you should trail brake deep into this turn, and tighten your radius to complete the turn. Stay off of the rear brake, trail brake with the front only.
Learning trailbraking is one of those techniques that is very valuable. On the racetrack, we trailbrake all the way to the apex at times, then it's back on throttle. That is used for getting into a corner fast, but is not the fastest line to take. We use it for passing.
The fastest line will be to end your braking just before the apex and it's right to maintenance throttle. That is a low rpm throttle input that will drive you right through the apex, and keep your suspension set just where you want it. Then you start to roll on the throttle to drive out.

I'm getting a little ahead of our topic...sorry. There is so much that I could teach you about cornering but it's too much to type here and you should be learning it first hand in a school setting. Again, go take a school. It's the best thing that you can do for yourself. I've got to get back to work now 

[EvilSteve]

How do you manage to late apex a turn, and then turn in The apex of a turn is the point at which you are the closest to the inside of the turn and you don't get to the apex until you have completed more than 50% of the turn.

Because a decreasing radius line is more than just where you apex.