Experiments With Turn In

[Bullet]

Hello Bullet and All,

 

Thanks for the feedback and the warnings, but I never said "roll on the throttle BEFORE turning in," and I'm talking about the turn-in, not the roll on so TCR1 literally does not apply. Since almost everyone has misread or misunderstood my question, let me see if I can reduce it to simplest terms:

 

1. Increasing speed + Increasing lean angle = Bad. Everyone agrees.
2. Reducing speed + Increasing lean angle = Good. Almost everyone agrees.
3. Maintaining speed + Increasing lean angle = THIS is my question--okay or not okay?

I'm really talking about the application of TCR2--remember that one? I didn't think this was such a hard question. I'll shut up now.

 

Let's discuss point 3 specifically, given that we have rolling friction from turn in , (i.e. the front wheel scrubs speed went turning in and leaned over) would it therefore be fair to agree then, then the only way to maitain phsycially the same speed would be to roll on the throttle? (hence point 3, is actually point 1)? If you're confusing a checked throttle and adding lean angle, the bike is actually slowing, not maintaing the same speed.

 

Make sense?

 

Bullet

[faffi]

Another point that can be confusing is that the majority of us riders - and possibly the majority on this forum - simply doesn't ride hard enough for these things to matter very much*. I suspect that when we think we flick the bike into a corner, we're probably hopelessly slow compared to really fast riders. Which means more grip in reserve for errors. Also, we're less likely to reach the levels of lean that will tax grip drastically, again leaving traction in reserve that can be used to cover for mistakes. Finally, we are rather slow to get on the throttle and will not get on it hard enough more often than not to cause drama.

 

In other words, street riders and many track "motionists" can get away with a tremendous amount of errors that would put a faster rider on his or her butt in an instant. Which is also likely why we can get away with testing different stuff and find no detrimental effects simply because we're too far from the limits. Like when I trail brake deep into corners; it's a result of me being afraid to set a firm turn-in point, dedicating to it and get it done in an instant smooth flick just as I smoothly but quickly get off the brakes. Hanging onto the brakes, then, for me is not a result of being brave and fast, but a safety line that allows me some leeway to adjust speed and turn-in point and apex. And I can do this safely because I'm not pushing anything to their limits.

 

* OTOH, this is of course a poor excuse for not doing this properly.

[rikker]

Hi there.

This is my first post but I've been watching this forum for a long time.

 

Well, I'm also facing this "throttle before slow turns crysis", and I really need your help.

 

So, I'm from Brazil and already did the Alex Barros Riding School (former brazilian MotoGP racer, I bet you remember him) and, after 7 trackdays, I still didnt decided how to proceed before slow turns.

 

When I attack fast corners, its all pretty clear for me: slightly roll off the throttle and keep it steady while leaning/counter steering (same technique for downhill corners and for the second leg of an Esse), but, for slow corners, man, what a doubt.

 

So, I'll tell you the approachs I've been trying, but still didnt felt confortable with neither.

 

1) Alex Barros: roll off while braking - till you reach zero throttle - let go your brakes, tip in, follow TCR1. Motovudu also states the same.

 

2) Dave Moss: same as Barros's teaches, but before you tip in, crack open the throttle, like a hair open, keep it steady till apex, and then follow TCR1.

 

3) Nick Ienatsch: roll off while braking, tip in with zero throttle & trailing the brakes till apex; then, follow TCR1.

 

So, what do you guys use as an effective technique?

I already try all above, but Im not really confident with none of them.

 

This is killing me... I lose focus thinking about what technique should I use at each slow corner.

I need to decide previously which one of them, so its one less thing to think about on my riding and have more fun.

 

Thanks.

[Hotfoot]

Hi there.

This is my first post but I've been watching this forum for a long time.

 

Well, I'm also facing this "throttle before slow turns crysis", and I really need your help.

 

So, I'm from Brazil and already did the Alex Barros Riding School (former brazilian MotoGP racer, I bet you remember him) and, after 7 trackdays, I still didnt decided how to proceed before slow turns.

 

When I attack fast corners, its all pretty clear for me: slightly roll off the throttle and keep it steady while leaning/counter steering (same technique for downhill corners and for the second leg of an Esse), but, for slow corners, man, what a doubt.

 

So, I'll tell you the approachs I've been trying, but still didnt felt confortable with neither.

 

1) Alex Barros: roll off while braking - till you reach zero throttle - let go your brakes, tip in, follow TCR1. Motovudu also states the same.

 

2) Dave Moss: same as Barros's teaches, but before you tip in, crack open the throttle, like a hair open, keep it steady till apex, and then follow TCR1.

 

3) Nick Ienatsch: roll off while braking, tip in with zero throttle & trailing the brakes till apex; then, follow TCR1.

 

So, what do you guys use as an effective technique?

I already try all above, but Im not really confident with none of them.

 

This is killing me... I lose focus thinking about what technique should I use at each slow corner.

I need to decide previously which one of them, so its one less thing to think about on my riding and have more fun.

 

Thanks.

 

CSS focuses primarily on number 1, although trail braking (#3) is used in certain types of corners or racing situations (generally tight corners after a straight that have a fast entrance and slow exit, or as a passing move).

 

What, specifically, is the doubt in your mind when approaching those slow corners? What are you worried will happen when you apply that first technique?

[rikker]

my worrie with #1 is: when I let go the brakes for tip in, it automatically extends the forks which unloads the tire and you lose traction.

 

when doing #3, I'm worrie about overloading front tire and wash out.

 

with #2, I never had enough throttle control fineness to give handlebars inputs while crack open the throttle and keep it steady till apex.

 

 

I already had an lowside at Interlagos Racetrack during a trackday (3 trackdays ago), but it happened because i gave too much throttle while leaned midcorner. Maybe this is killing my confidence...

[Hotfoot]

OK, got it, that all makes sense. Let's tackle these one at a time.

 

"with #2, I never had enough throttle control fineness to give handlebars inputs while crack open the throttle and keep it steady till apex."

 

Agreed, it would take a lot of finesse and concentration to do this. One way to get a similar result with less effort is to increase the idle speed of your bike so the RPMs don't fall off so far when you let off the throttle. You could try increasing it 500-1,000 rpm and see if it helps the bike feels a bit more stable at tip-in. Be cautious of entry speed in your first few turns after adjusting it, because your bike is likely slow down a little less than before.

 

"when doing #3, I'm worrie about overloading front tire and wash out."

 

Cornering forces plus braking forces do put a lot of load on the front tire, and it does take careful brake control to manage this technique. Again, this can cost a lot of your attention which may be better spent on other things - like looking ahead at reference points! Trail braking is a more advanced technique, does have some additional risk of overloading the front, and should probably used judiciously - if you do a forum search you can find plenty of discussions about when and where it might make sense to do it.

 

"my worrie with #1 is: when I let go the brakes for tip in, it automatically extends the forks which unloads the tire and you lose traction."

 

If the forks extend between when you release the brakes and when you turn in, it makes the bike feel unstable, which is unnerving for sure. Here are a couple of things you can do to handle this:

 

1) Have a suspension person take a look at your bike, your front rebound may be too quick (the rebound damping set too soft) so it springs back too sharply after braking. The compression (or preload) could also be too soft causing the front end to dive excessively under braking.

 

2) The ideal is to be tapering off the brakes as you approach your turn point, ideally releasing the brake right when you turn in. The cornering force compresses your front end, so when the timing is right the front end load transfers from braking load to cornering load so it is never unloaded. If, however, you brake hard, release the brake abruptly, coast for bit, THEN turn in, you get the forks compressing, extending, and compressing again. If your front suspension is really soft, this can be dramatic and a little disconcerting!

 

A good way to accomplish your braking is to apply the brakes smoothly (not a stab) at the beginning of your braking zone, get the bulk of the braking done at the beginning, then taper off the braking as you approach your turn point, releasing it just as you turn the bike. That way there is never a chance for the front to pop up sharply (because you are tapering off your braking), even if your conering force is much lower than your braking force (which would be the case if you were to brake very hard but take the corner at a tentative pace). As the pace comes up, the cornering force is greater, so you dont' have to taper the brakes off quite so gradually to keep the front down through the corner.

 

I'm not sure what you have or haven't done with your suspension but it is VERY common for the front to be too soft on a street bike, so do have someone look at your suspension settings. When set up right, not only will the bike feel more planted and stable, it will be easier to turn the bike when the front stays partially compressed through your whole braking/turning action.

 

Does that help?

[bradvanhorn]

Edited: Never mind, Hotfoot provided a far better answer than I

[rikker]

thanks HF, great info; I'll take a closer look at my forks and decide what kind of approach I'll use for slow turns (#1 is probably the winner).

[rikker]

What does the Dunlop technician says about braking, at 1:15?

English isnt my native language so Im having trouble to understand what he says from 1:15 to 1:21... seems important.

 

[Hotfoot]

What does the Dunlop technician says about braking, at 1:15?

English isnt my native language so Im having trouble to understand what he says from 1:15 to 1:21... seems important.

 

 

He says that some riders like to "trail in" the brakes (meaning hold the brakes on past the tip-in point and into the turn), that some "trail" longer (farther through the turn) which gives a different shape to the tire. He says that as you are trailing the brakes you are forcing the tire in the other direction which makes turning more difficult.

 

He then says other riders tend to slam the brakes on (which means apply the brakes very hard and fast) and then take them off and then turn. Then he says there are "two different ways"... a slower rider would compress the tire more lightly (I think he means "slower with applying the brakes", not slower in general) but that a "faster rider" (who appplies the brakes quicker with more force) would make the tire compress a lot, and quickly, like a spring - he shows a "bounce" with his hands.

 

The next person goes on to talk about how compressing the tire more can make it easier to turn and give more grip, and that there is a risk when trail braking because if the tire is heavily compressed when leaned over you can overload it and slide.

 

It seemed like he was talking about the challenge of designing a tire so that it will work well for BOTH types of riders: those that like to trail the brakes through the turn, and those that like to brake hard, then release the brake as (or before) they turn.

 

Does that help? If there are words or phrases that are not clear please let me know and I will try to explain more, if I can.

[faffi]

Great find, rikker Very interesting.

 

I noticed Smith saying you have less grip for braking as you lean because you have less contact patch. Which really isn't the case most of the time. The reason you have less grip for braking is that more is used to counter centrifugal forces primarily in addition to whatever other forces are fed into the bike (steering, braking).

[Lnewqban]

.........and decide what kind of approach I'll use for slow turns (#1 is probably the winner).

 

Approach #1 has been the winner.

 

Traction is proportional to the weight on the contact patch and the size of that patch.

 

As long as you are braking (decelerating during a turn), you are not achieving the ideal 40 front / 60 rear percents of weight distribution; hence, you are unnecessarily overloading the front tire and setting the suspension off its ideal point of operation.

 

Get done with all the deceleration before beginning of the turn and smoothly transition from deceleration to acceleration while fine dialing your entry speed.

 

After you master that sequence of inputs, you will not need to think much and will concentrate on trying higher and higher entry speeds in order to achieve faster turns.

 

Check this article:

 

http://www.sportride...king_potential/

[Kruizen]

I'm still having issues wrapping my head around a couple of points, because I think that I am associating max lean angle with the turn apex.

 

So as long as at the turn in, I have set my steering properly and won't have to adjust it thru the turn(i.e. adjusting lean), I can start getting back on the throttle almost immediatly? via throttle control rule 1.

 

But if I mess up my turn in, and continue to add lean angle during the turn, then I cannot(shouldn't) add throttle until I've hit max lean angle for the turn?

 

So in a medium speed turn, say thats constant radius, in simpllified terms the order would be:

Brakes on, brakes off(throttle off), turn in(set fine), crack on the throttle progressively and gradually increasing to the drive out.

[csmith12]

If you need just a slightly tighter line, have a look at the hook turn technique. It will allow you to follow all the other techniques AND tighten your line if it needs adjustment midcorner.

 

Aside of throttle, brakes and such, what other major factor has a large effect on the bikes ability to turn?

[mugget]

Hi Kruizen,

 

It may be that associating max lean angle with the turn apex is counterproductive. I'm not sure if you're thinking this way, but what I used to do was try and actually aim to reach max lean at the apex. This is completely backwards and is going to even result in slow/dangerous riding on some corners.

 

On certain corners it may be true that you reach max lean angle for that turn (not max lean for the bike) at the apex, but this will not be true of every corner.

 

Try not to think of reaching max lean as a goal. As you improve your quick turn ability and your accuracy and ability to judge speed improves you will actually be able to ride a given corner at the same speed (perhaps even faster) using the same or less lean angle as before.

 

So as long as at the turn in, I have set my steering properly and won't have to adjust it thru the turn(i.e. adjusting lean), I can start getting back on the throttle almost immediatly? via throttle control rule 1.

 

I'd say that's pretty much it. Although there is a very helpful way to know for sure in any turn when to get back on the throttle - this is when you know that you are going to hit your intended exit point for the corner (or at least when you know you're not going to run wide off track).

 

For example there was one particular big, open fast corner when I did Level 1. I would turn and when I was sure I would hit my corner exit point I picked up the throttle as I headed to the apex. There was maybe once or twice where everything lined up so that I was back on the throttle the very moment I had finished turning. But notice that I was back on the throttle heading towards the apex? Using the apex to judge braking/turning/throttle will throw you off. There's nothing particularly special about "hitting the apex", for instance if you stay off the throttle just to get within 10cm of the inside curbing when you could have actually been back on the throttle 10 metres ago, you have just gone slower than needed...

 

As a side point talking about the apex, every single rider does "hit their apex" 100% of the time. Their apex simply means the place in a turn where their line comes closest to the inside of the corner. A rider could take the same corner 100 times and have a different apex in each. The point is that there isn't really any one set apex point for each corner, which just goes to show why judging your riding by an imaginary "apex" will throw you off.

 

But if I mess up my turn in, and continue to add lean angle during the turn, then I cannot(shouldn't) add throttle until I've hit max lean angle for the turn?

 

Try not to think of it in terms of judging your throttle according to your lean angle. I think it's better to go by the method of adding throttle when you know you'll reach your exit point (or not run off track) because not going off track at the exit is more important than whether or not you've just reached max lean for that corner. If you use that guideline everything will fall into place anyway - if you are heading to the corner exit you will already be coming up from max lean. If you only pick up the throttle when you're sure you will hit your exit point then there is no way that you risk adding throttle while adding lean (at least I haven't experienced, and can't imagine any situation where this wouldn't be true).

 

I hope that helps!

[Lnewqban]

I'm still having issues wrapping my head around a couple of points, because I think that I am associating max lean angle with the turn apex.

 

Kruizen,

 

We need to go back to basics:

 

Lean angle is a consequence, not something that you decide directly.

Your only decision is speed at the beginning of the turn and how much you accelerate along it.

For a turn that traces a constant radius semi-circle, each speed will auto-generate a lean angle.

That is the angle at which all the forces that could roll the bike are balanced and cancel each other.

Via counter-steering, you could force the bike to abandon that natural angle, but the immediate consequence would be a roll (either to the inside or outside of the turn).

 

Each time that we make our bike trace a semi-circular trajectory which constant radius is bigger than the constant radius of the actual curve, we have an apex.

See the attached diagram below.

We adopt that bigger radius in order to make the trajectory shorter, to increase our speed some and to complete the curve a fraction of a second earlier.

If that bigger radius is constant (ideally, because it is not so for quick flick technique,...........yes, a discussion for later), the speed and consequent lean angle should be constant along the curve (actually, both increase some as we accelerate to keep the 40/60 weight distribution).

 

Max lean angle at apex means that your speed is increasing from entry to apex and then decreasing after apex, which has no reason to be.

 

So as long as at the turn in, I have set my steering properly and won't have to adjust it thru the turn(i.e. adjusting lean), I can start getting back on the throttle almost immediately? via throttle control rule 1.

 

Yes, as early as possible, depending on road, traffic and visibility conditions.

Remember, whenever you are not accelerating moderately along the curve, you are overloading the front tire.

 

But if I mess up my turn in, and continue to add lean angle during the turn, then I cannot(shouldn't) add throttle until I've hit max lean angle for the turn?

 

The only way to mess up the turn in is by using the wrong point or the wrong entry speed, lean angle has nothing to do with either one.

Excessive entry speed = cannot accelerate = overload front tire (even more if you brake or cut the throttle).

Insufficient entry speed = everyone passes you.

 

So in a medium speed turn, say thats constant radius, in simplified terms the order would be:

Brakes on, brakes off(throttle off), turn in(set fine), crack on the throttle progressively and gradually increasing to the drive out.

 

Yes, but with a smooth transition between each step.

[Alfred.Rodriguez]

But if I mess up my turn in, and continue to add lean angle during the turn, then I cannot(shouldn't) add throttle until I've hit max lean angle for the turn?

 

Let me just add that YES - indeed you should NOT add throttle when adding lean angle! Off the throttle, or just stop the roll-on/roll-off... Wait for the bike to settle at the right lean angle that brings you at the intended line. Then you can resume rolling on the throttle.

 

The only way to mess up the turn in is by using the wrong point or the wrong entry speed, lean angle has nothing to do with either one.

Excessive entry speed = cannot accelerate = overload front tire (even more if you brake or cut the throttle).

Insufficient entry speed = everyone passes you.

 

On the other hand, you could ALSO mess a turn with a SLOW steering rate; which would require more lean angle to complete the turn.

[Kruizen]

Thanks for the replies. I have to unprogram my head from the track organizations I've rode with saying hit this cone and that cone. While they were good reference points in the beginning now they are messing me up, I need my own reference points, and timing points.

 

Working on digesting twist ii, and soft science and its starting to click.

[csmith12]

I review my reference points every so often, sometimes I have to change a few, other times it's only one. I have my set of clues it's time to change one;

 

Being visually scattered (very subtle)

Corner feels rushed

Throttle control

Exit feels sluggish

Steering corrections

Increased pace

ect.. ect...

 

What clues you that the markers are now messed up?

[Kruizen]

These cones are on the exterior of the track, are set up each day(possibly by someone different). While I don't think they are completely wrong. My thoughts are these:

 

1. they are not my RP, or timing points for my plan of that turn

2. they are set up by someone else that my have a completely different plan for the turn or the day as a whole

3. Ive actually been told by someone with one of the track organizations that they purposly move the apex cone and additional 4 feet into the turn, because they feel its safer that way

4. the track organizations Ive rode with in the beginner/intermediate levels have been focused on the riders "hitting the cones" i.e. specifically the turn in and apex cone. ESPECIALLY the apex cone. while I think that helps the beginner rider lean the track and line. it focuses to much on the apex and not the entire product of the turn.

5. the turn in cone may be close to where a good turn in should be, its not mine, its not on the track, its on the exterior of the track, drawing attention in the wrong way.

6. The cones may be a good way to assist with finding my own RP's for those turns, but I don't feel they should be used as the RP's as prescribed by the coaches/organizations.

 

These are a few of the points bouncing around in my head. I can think of a couple of turns that by using the "cones" has you leaned over way to long in the turn. Had to get these on paper, now back to work. Really NEED to get back on the track, winter is way to long.