Questions for Keith Code - Round Two

[Burning1]

I definately think that is a hell of a list. The only one that I wouldnt agree with is number 5. Getting on to the center of the tire would create "taller" gearing, which is actually less mechanical advantage. On the exit of a turn, it is all about acceleration, and shorter gears = better drive. I'm no physics major, but I'm pretty sure that the smaller rolling circumferance of the side of the tire creates shorter gearing.

Taller gearing in 2nd is still better than shorter gearing in 3rd.

It might be useful if the rider is about to red-line it. He or she might be better off getting a few RPM out of the tires than trying to shift while at maximum lean angle.

I've never tried this, so I'm not sure if this matters in practice.

 

[tzrider]

I definately think that is a hell of a list. The only one that I wouldnt agree with is number 5. Getting on to the center of the tire would create "taller" gearing, which is actually less mechanical advantage. On the exit of a turn, it is all about acceleration, and shorter gears = better drive. I'm no physics major, but I'm pretty sure that the smaller rolling circumferance of the side of the tire creates shorter gearing.

Consider that in some long corners, you may be exiting near a shift point. The engine rpm difference between max lean and vertical is about half an upshift, so getting the bike upright can let you hold a gear longer and remain in the powerband.

 

[Keith Code]

pick up technique

Using the pick up technique can be used to:

1. use more throttle earlier in the turn
2. maintain a line when the corner goes off camber
3. reduce wear on the sides of the tire
4. traverse a low traction area (oil, water, bump) in the corner
5. change the effective gearing on the exit of the turn

I have been through level 3 and I am embarrassed that I am not sure these are the 5 examples you are looking for. Honest, I really was paying attention in class, but it has been a few months.

Rick

Rick,

WOW, I like the off camber one and its true, it would help and I will add that to my breifings from now on as the sixth reason to master the pick up technique. BRILLIANT.

Thanks,

Keith

I'm always amazed at what can be discovered when an area of riding is researched. Thanks to all.

 

[Lazerus]

"Your right about the effect it has but there are times when taller gearing might work better.
to prevent a wheelie or tire spin, or to carry a little more speed without having to shift.
__________________"


True, "there are times", but I think that these would be the exception rather than the rule. I dont think that standing the bike up would be a significant enough gearing change to prevent a wheelie, given the same amount of throttle, etc. I also think that controlling the slide by picking 'er up has more to do with the change in the COG and contact patch than the gearing change. The only time i can think it would be advantageous to retain your current gear when driving off of a corner is if it's followed by another turn that requires the same gear, in which case, drive off of the first corner is less important than drive off of the final corner. If it prevents you from an upshift, immediately followed by a down shift, then I agree. Usually, the corners that you are gaining the biggest advantage of a "good drive" off of are ones leading to a fast section that will require upshifts.... why do I feel like we are being devils advocates?

 

[tzrider]

The only time i can think it would be advantageous to retain your current gear when driving off of a corner is if it's followed by another turn that requires the same gear, in which case, drive off of the first corner is less important than drive off of the final corner.

Here's another: You're past the apex of a medium speed corner and nearing a shift point. This corner is followed by a long straight. You can choose to upshift while leaned over or stand the bike up and delay the shift point until the bike is going straight. What might you do and why?

 

[Lazerus]

tzrider and burning1:

If the change in profile between upright and full lean is worth half an upshift, then a short 3rd and a tall 2nd would be equal. I do agree that having the bike more upright on exit is the way to go.... but I also think that shorter gearing= greater acceleration. In an effort to save face, i'm gonna have to resume this discussion when I am no longer under the influence of vicodin Damn wisdom teeth anyway.

So is that it Keith? is ktmle the big winner?

 

[Lazerus]

Here's another: You're past the apex of a medium speed corner and nearing a shift point. This corner is followed by a long straight. You can choose to upshift while leaned over or stand the bike up and delay the shift point until the bike is going straight. What might you do and why?

When I am past the apex, I am beggining to stand the bike back up anyway. I would stand the bike up as usual and shift when necessary. In some instances, I may grab the gear to allow me to get WFO without spinning up the rear... or if the turn is long enough to be back in the powerband in the next gear before exit is completed. Of course, I have become comfortable with making smooth shifts, both up and down, while leaned, and would not advocate it's practice to new riders

 

[tzrider]

Of course, I have become comfortable with making smooth shifts, both up and down, while leaned, and would not advocate it's practice to new riders

It's fine and sometimes necessary to upshift leaned over. A good skill to have. Any upshift, however, will interrupt thrust momentarily. If your driver were interrupted by a quarter second on your upshift, would the effect on acceleration be different if you were in a corner vs. out of it?

 

[Lazerus]

I believe that while in the corner, you are limited in your acceleration due to traction devoted to cornering, thus if I have to chose a place to not have thrust, I would pick it to be at a place that I can't use maximum acceleration anyway, thus maximizing the time that I can be at full thrust once the bike is upright. In other words, i would rather be coasting momentarily at a point that I am only accelerating 2 feet per second per second rather than at a point where I am accelerating 10 feet per second per second. But like I said, im drugged

 

[tzrider]

I believe that while in the corner, you have a are limited in your acceleration due to traction devoted to cornering, thus if I have to chose a place to not have thrust, I would pick it to be at a place that I can't use maximum acceleration anyway, thus maximizing the time that I can be a full thrust once the bike is upright.

Not bad logic, but looking at it from the other side, in which of the two locations is there more drag on the bike's momentum?

 

[Keith Code]

pick up technique

"Your right about the effect it has but there are times when taller gearing might work better.
to prevent a wheelie or tire spin, or to carry a little more speed without having to shift.
__________________"


True, "there are times", but I think that these would be the exception rather than the rule. I dont think that standing the bike up would be a significant enough gearing change to prevent a wheelie, given the same amount of throttle, etc. I also think that controlling the slide by picking 'er up has more to do with the change in the COG and contact patch than the gearing change. The only time i can think it would be advantageous to retain your current gear when driving off of a corner is if it's followed by another turn that requires the same gear, in which case, drive off of the first corner is less important than drive off of the final corner. If it prevents you from an upshift, immediately followed by a down shift, then I agree. Usually, the corners that you are gaining the biggest advantage of a "good drive" off of are ones leading to a fast section that will require upshifts.... why do I feel like we are being devils advocates?

One other element that should be added here on this line of discussion is traction control.

Some bikes (Ducati Moto GP machines as an example) deliver power not only on wheel spin but, I have been told, also based on lean angle. The data I got was the bikes at extreme lean are actually "governed" for 116 bhp, increasing proportionately as the bike goes more vertical ( picked up).

Keith

 

[Keith Code]

pick up technique

When I am past the apex, I am beggining to stand the bike back up anyway. I would stand the bike up as usual and shift when necessary. In some instances, I may grab the gear to allow me to get WFO without spinning up the rear... or if the turn is long enough to be back in the powerband in the next gear before exit is completed. Of course, I have become comfortable with making smooth shifts, both up and down, while leaned, and would not advocate it's practice to new riders

This touches on another aspect of creative riding that we saw with the young rider who came over and put in the quick laps at Sears point. He had a technique of pinning the bike as he picked it up, starting an agressive wheel spin and then snapping it up the final 20 degrees or so and getting a serious slingshot drive off the corner.

Really fun to watch.

Keith

 

[ktmle]

Using the pick up technique can be used to:

1. use more throttle earlier in the turn
2. maintain a line when the corner goes off camber
3. reduce wear on the sides of the tire
4. traverse a low traction area (oil, water, bump) in the corner
5. change the effective gearing on the exit of the turn

I have been through level 3 and I am embarrassed that I am not sure these are the 5 examples you are looking for. Honest, I really was paying attention in class, but it has been a few months.

Rick

After looking back through the thread AGAIN, I see that I left out the most obvious use of the technique which most everyone else has mentioned at some point:

6. save a slide

Am I getting close, Keith? If i think about this much more my head is going to explode. Although there are certainly much more mundane things I could be thinking about.

Rick

 

[Keith Code]

Pick Up Technique

Lots of good answers and I'm going to list the points now and keep it completely democratic and let the forum vote on who the winner is:

1. Better drive off the corner because the bike is more vertical earlier on the turn's exit.

2. Wet or slippery conditions are less dangerous with less lean angle.

3. Save a crash. Picking the bike up into a slide (not a controlled power slide) is one of the few options that can save it.

4. In a controlled power slide, picking the bike up into it allows the rider to maintain good throttle control and helps avoid highsiding and shakey drives.

5. Maintain tire profile. Because most riders are lazy bringing the bike up out of turns tires have the tendency to "flat Spot" on the sides, like freeway riders flat spot their tires in the middle. Either situation makes the bike feel squirrelly in corners.

6. Now added: Off camber situations can be run with less lean, higher speed and a better drive.

The other aspects like collision avoidance in a turn are good ones as well although the above are more universal. 5 of the six could be used by just about anyone on any given day. Only the controlled tire spin is pretty much racing only.

You guys vote--I ship the tires. Better set a limit on this...voting ends Sunday night, 10 February at midnight.

Thanks for the ride.

Keith

PS: What gear you are in is becoming less and less important as the effective range of torque and horsepower broadens. If we were talking about 125s or 250s it would be a hot issue. On any new 600 with a pipe and electronically corrected fuel delivery you can easily be off a thousand or two and not lose 1/10th of a second on the drive.

Keith

 

[ktmle]

Deciding the winner of an essay contest is certainly not my area of expertise, so if someone has a better idea, please jump in. I propose we each cut and paste our list with the date and time and then show how it correlates to Keith’s list. Then we can all vote on who got the closest the earliest. I am not sure we should include the off camber thing since that was not part of Keith’s original list. But I would be happy to accept any bonus points for the idea.

Here is my list from today at 2:59 pm:

1. use more throttle earlier in the turn
2. maintain a line when the corner goes off camber
3. reduce wear on the sides of the tire
4. traverse a low traction area (oil, water, bump) in the corner
5. change the effective gearing on the exit of the turn
6. save a slide


1. Better drive off the corner because the bike is more vertical earlier on the turn's exit.
1. use more throttle earlier in the turn

2. Wet or slippery conditions are less dangerous with less lean angle.
4. traverse a low traction area (oil, water, bump) in the corner

3. Save a crash. Picking the bike up into a slide (not a controlled power slide) is one of the few options that can save it.
6. save a slide

4. In a controlled power slide, picking the bike up into it allows the rider to maintain good throttle control and helps avoid highsiding and shakey drives.
6. save a slide

5. Maintain tire profile. Because most riders are lazy bringing the bike up out of turns tires have the tendency to "flat Spot" on the sides, like freeway riders flat spot their tires in the middle. Either situation makes the bike feel squirrelly in corners.
3. reduce wear on the sides of the tire

6. Now added: Off camber situations can be run with less lean, higher speed and a better drive.
2. maintain a line when the corner goes off camber

I guess my point about changing the effective gearing didn’t make the cut. But my point number 6 is sufficiently ambiguous to fit 2 of Keith’s points.

Let’s hear from everyone else.

Rick

 

[Lazerus]

Although I would love to have a new set of qualifiers to use at my next trackday per Keith's advice, I think that "ktmle" should get them. Anyone who can come up with a new idea that Keith will adopt as part of his curriculum deserves commendation at the least. Just think, your idea will be spread to thousands of students now Once again, thank you Keith for putting up a contest to get our minds motivated!

 

[kxmike]

I've got to go with ktmle as well.



I run michelins anyway!


Thanks to Keith code for making us think again

 

[Keith Code]

pick up technique

I'll wait a day.

I'm not nit picking on ktmle but "reduces tire wear" should be looked at for a moment.

I don't think the pick up technique would reduce tire wear, rubber would still shed off the tire.

The point of the technique in this regard is more of an economic factor. You can use the tire until there's almost no rubber on the carcass and it will still feel stable.

Definitely more of a track day consideration than street (depending on how hard you ride).

keith

 

[Keith Code]

pick up technique

Oh ya, one more point.

There really is a seventh and it has been mentioned by a couple of posters.

The suspension does work better with the bike leaned less.

I was just going over some correspondence I had with Tony Foale where we were talking about the same subject.

As the bike leans over more the bike has the tendency to roll as it tries to handle the pavement. This is due to the suspension becoming less compliant the further over you go.

In practice, they don't really roll enough to notice. Tire construction and sidewall flex also becomes an important suspension component at steeper lean angles.

Now you are in the area of how stiff to design and construct the chassis the axels and the swing arm. Too stiff not good, too flexey not good.

The turn of the century ZX9s were a good example of that. The skinny axel model, I think that was the 1999, handled better than the larger diameter axel model, because the bike needed the flex to maintain stability/traction.

The point is: number 7 is better suspension compliance due to less lean angle.

Keith

Websters 20th century dictionary:

Research, Diligent inquiry or examination in seeking facts or principles; laborious or continued search after truth.

 

[Lazerus]

Another tid bit that I picked up from a zoom zoom instructor on this topic. Usually, people want to get back into the saddle ASAP upon corner exit. This can be bad for all of the reasons listed above, but also because of the effect that your weight transfer can have on the bike. If you are accelerating at the threshold of rear tire traction, then try to hoist yourself back into the seat, this can be enough to push you from grip to slide... whereas picking up the bike and staying away from it allows you to maximize contact patch early, and keep the tire hooked up through exit as well. Kind of the equivalent of setting your body up early for the corner to prevent from upsetting the chassis, only at the other end of the turn Thanks to Brian Zimney and his Body Positioning clinic for that one