Killboy - NOT!!!! But we did try some Ridin' Pics

[David]

I disagree.

 

Now, if you're bothered that we're doing it in your thread, that's another matter, and I'll gladly stop. But the discussion is valuable.

[Huzband]

I'm going to suggest that at this point we drop it. The discussion is no longer bringing up new points of riding techniques, or even new points of persuasion, but is heading towards argument. Time to let it go and move on.

 

Thanks,

 

Jan

 

 

No, wait. Don't be so quick to kill your own thread, Jan.

 

I kinda like watching our Proprietor Emeritus go Mano-a-Mano with with a young stud of a cop.

 

I'd like to see who outlasts whom.

 

[FlyingFinn]

Just when I got out the popcorn...

[Twisties]

Now, if you're bothered that we're doing it in your thread, that's another matter, and I'll gladly stop

 

No problem.

[Joe Frickin' Friday]

Lying to myself about what??? That I could pick a line in a curve as well, sitting up straight, as you kissing the mirror???

 

 

If you had followed my line through this curve while sitting straight up, you'd be sliding off into the weeds.

 

Had I been leaning even more to the inside as I should have been, we would not be seeing sparks under the left saddle bag. (yes, there were many things I did wrong in that turn; click here for the whole sordid story.)

 

Relative to a sit-straight-up posture, leaning to the inside confers several benefits: improved cornering clearance, improved (i.e. more vertical) suspension action, more neutral steering action. You can use those benefits to negotiate a corner at high speed, or enjoy higher margins of safety while traveling at a sedate speed.

[Bullett]

OK, Danny said I have "early apex." (gosh, that sounds bad, perhaps even unnatural).

 

Will you riding gurus explain:

 

What is the apex of a turn?

 

Can there be more than one apex in a turn?

 

What factors do you use to determine where you will place the apex of a turn?

[Endobob]

I disagree.

 

Now, if you're bothered that we're doing it in your thread, that's another matter, and I'll gladly stop. But the discussion is valuable.

 

The discussion is fantastic! This thread and reading again the thread in '04 that Mitch kindly reminded us of has helped reinforce the lessons I learned at a RideSmart class. More LEO's and MSF instructors need to take the class!

[David]

Sharon, the apex is the innermost point on the arc of the turn.

 

Yes, there are frequently more than one, particularly on longer turns.

 

Where that is placed depends on these factors: what allows you to see well; what keeps you away from oncoming traffic; what helps you avoid surface issues (gravel, dirt, obstacle, etc.), and one other important thing: putting it in the right place helps you correlate your greatest lean angle with your slowest speed.

 

It's hard to describe with words--I wish I could do this on a white board.

[leikam]

Perhaps this diagram would help?

 

[Shaman97]

It's hard to describe with words--I wish I could do this on a white board.

 

Can you, or anyone recommend a video/DVD for this?

[Boffin]

The terms ideal turn-in point and late turn in-point, with their respectice apexes on that diagram are correct for the track. On th eorad however, the late turn-in and apex are also the correct ones as they allow much more vision through the turn and avoid putting you into a situation that was hidden earlier in the turn. Not as fast, but safer - which is what road riding should be about.

 

Andy

[motorman587]

Where did I say that's how I do it and it is ok and I am not dead????

 

I became a motor officer in 1994 with 40 motor hours of schooling. Sitting up straight was taught. In 1997 I became a motor officer instructor (80 hours) and sitting up straight was taught to be taught. In 1998 I became a ridercoach (80 hours) and sitting up straight was taught. In 2001 I became an adjunct instructor to teach motor officers to become motor instructors. Sitting up straight was taught. In 2002 I went to Kevin Schwantz's Suzuki School. They teach hanging off the bike. In 2003 I became a member of this board and through some weekend riding warrior's opinion I am told that sitting up straight is wrong, and should get my head out of the sand, I am lying to myself. I am stud.................Wow the name calling

 

Again it is a techniques for different riding styles. Lean angles all start at the entry point. Too fast more lean angle. I do not think I would've been the weeds in the picture above. First I do not ride like that, ask Tim the Tallman. Second I would not be that close to the double yellow. Entry speed is the speed that allows roll on throttle. You either keep the throttle steady or roll on the throttle. But this all depends if you can see the exit. If you can not see the exit then there is no roll on, just steady.

 

This past Spring I was able to ride with someone on his board who kept saying he was sorry. I was following him. Sorry for what??? He said that he felt he was too slow in the curves. I told him he was fine, he had a nice head turn, nice smooth entry speed, sat up straight etc........and he was quite fast in the curves. I felt that and am more convinced now that some members beleive, reading/seeing pictures that you have ride agressive to make those curves. While sitting up straight is nice relaxed sitting postion and using the "slow" in the curve as you enter, using the delayed apex. you will have enough/more lean angle. Got to go to work and sit up straight. But yet will be chasing somebody in a curve sitting up straight.

[tallman]

You said, ask me, so here goes.

You're both faster than me.

Years ago I posted on this when a similar discussion was going on. I felt that it would be interesting to compare the results of these two riding techniques, in a closed environment, just for kicks.

What both David and John are forgetting, and as a Teacher I am guilty of this at times also, is that both of you are coming from a POV that is substantially different than many other riders.

The difference between a PGA member, golf professional, a scratch player, and a weekend golfer. All play the game and have moments of being in the zone.

But, the professional is there more often, and the PGA member is, at his/her worst, usually better than all the others at their best.

David, as a student of the art of riding, and then an instructor at track schools, your experience and understanding of the art of riding is much greater than the average rider. So is your application of that knowledge.

John, as a trained motor officer, and one who probably practices more in amonth than some do in a lifetime of riding, your experience and application of the techniques you use is fantastic.

Both techniques have advantages, and as Mitch pointed out, some disadvantages.

Personally, I borrow from both, and then, as John said, try to avoid being in a situation where I am at the limits of traction so I don't have to find out what those limits were.

 

On the track, and there certainly are track skills that can carry over to the street, the riding environment is different than on the street. I think it is much more likely that track skills can carry over to the street and less likely that street skills carry over to the track.

I try to ride as if I am on a public road, and not the track.

Yes, I can go faster.

But don't feel the need to.

David I believe you posted something like that a year or two ago. You said that w/more track time, you were less inclined to push limits on the street, and even reduced your street riding as you felt that the track was (insert appropriate term for better/more rewarding).

John, I've ridden thousands of miles with you. You rode your LT to places in Alaska that some don't take a GS. Not many could do that.

Now, coming back to technique, some might say that it is the result that counts. Others, like gymnastics used to be (wait until you see the Olympics ), will say that if you're not using the right technique the results don't matter.

I think both of you love to ride, and have a passion for imparting knowledge, not from an egotistic POV, but from a genuine desire to help others be safer on their motorcycle.

You guys have a lot in common.

Perhaps that is why I put up with both of you.

David is correct that in some circumstances, for most riders, if you have put yourself in a certain situation on the motorcycle, then the technique involving change of body position will increase or maintain lean angle and allow you to (hopefully) ride through the situation. I think most of these situations are caused by improper speed/entry/apex.

John is correct that for many riders, they would be better off not putting the bike in a situation that requires application of radical (track professional) technique to survive the moment.

For many of us, that situation can come about too easily, and certainly is more likely to happen to us, than to either of you two, because of your experience and practice.

 

So, how about a session w/David on an RT-P, at motor officer course, loser buys the bagels, and a session on the track, loser buys the beer?

 

I get a lot from these exchanges.

I had PM'd David earlier in this thread about something I do in a turn, unsure of the "rightness" of it, only to have Ed and Russell both bring up the same technique in the thread. Apparently I picked it up, probably here, when someone passed on knowledge gleaned from a track session.

As long as exchanges are kept civil, and information is exchanged, I appreciate the opportunity to evaluate my riding technique, decide if I want to incorporate something new, or remind myself of the need to practice, to determine a bad habit needs to be fixed, or reinforce something that is good, I find these threads helpful.

 

Time to differentiate between increasing/decreasing radius turns, with/without elevation changes, off/on camber turns with/without elevation changes, throw in some precipitation, and whether throttle repsonse is improved with synthetic oil.

Best wishes.

Hope you both make it to BRR.

[Joe Frickin' Friday]

...I became a motor officer in 1994 with 40 motor hours of schooling. Sitting up straight was taught.

...

In 1997 I became a motor officer instructor (80 hours) and sitting up straight was taught to be taught.

...

In 1998 I became a ridercoach (80 hours) and sitting up straight was taught.

...

In 2001 I became an adjunct instructor to teach motor officers to become motor instructors. Sitting up straight was taught.

 

You seem to be very focused on the fact that sitting up straight is what you were taught. So much so, in fact, that you refuse to even acknowledge the benefits of leaning to the inside, which have been delineated several times now; you dismiss it all with a wave of the hand and a declaration of "that's not what I was taught." It's become a point of dogma for you, rather than a rational discussion.

 

I do not think I would've been the weeds in the picture above. First I do not ride like that, ask Tim the Tallman. Second I would not be that close to the double yellow. Entry speed is the speed that allows roll on throttle. You either keep the throttle steady or roll on the throttle. But this all depends if you can see the exit. If you can not see the exit then there is no roll on, just steady.

 

John, you're missing the whole point, and I'm starting to wonder whether it's deliberate. As I have admitted previously, there were many things I did wrong on that turn - but leaning off to the inside was what kept me from low-siding, in spite of all I did wrong; had I not been leaning off, I would probably have been in the weeds.

 

Do you disagree that leaning to the inside during turns confers several safety advantages (when compared to sitting straight up)?

[amz]

Nice and thoughtful post. I see the points, and think you are spot on with a lot. I do disagree with one statement of yours though (my emphasis below).

 

John is correct that for many riders, they would be better off not putting the bike in a situation that requires application of radical (track professional) technique to survive the moment.

For many of us, that situation can come about too easily, and certainly is more likely to happen to us, than to either of you two, because of your experience and practice.

 

If you are talking about the 'kiss the (inside) mirror' technique (i.e. not hanging off the m/c with your knee dragging on the road), I do not believe that to be a 'radical (track professional) technique.' Instead, I see that more like the application of basic physics to better manage ones risks going through corners. Do you have to 'kiss the mirror'? No. But doing that will increase your safety margins over sitting up in line with the m/c lean.

 

Great thread! Thanks especially to David and John for bringing this up; I think a lot can be learned from discussions like these, especially when they stay civil

[tallman]

No, if I meant "kiss the mirror", I would have said that.

I'm talking radical body shift, hanging off, knee dragging, race bike (set up perfectly for that track and rider) technique applied in an instant to a sport touring bike as an attempt to salvage a dangerous situation.

 

We see track racers go down in every (almost) race.

 

I thought long before writing that statement, but my point still is that you can do more before the turn to prevent that situation (as Mitch says above).

 

[amz]

We do indeed agree then. Although when done correctly, it could safe one's bacon - but performing that type of stunt in the middle of the corner (instead of during set-up) is quite a tricky manoeuver...

[Joe Frickin' Friday]

It's hard to describe with words--I wish I could do this on a white board.

 

Here's the diagram that was in my other thread:

 

 

The red line is what I followed in my turn, and is similar to some of the pics that started this thread: very soon after the start of the turn, the rider moves to the inside, i.e. an early apex turn.

 

The green line is closer to ideal: stay away from the inside of the turn until you can really see through it nicely, then straighten the bike up a bit and get on the gas. This is a late-apex turn.

 

Leikam thoughtfully added the blue line to my initial diagram. This represents a way to correct for what starts out as an early-apex turn: straighten up, scrub off some speed with the brakes (the arrrows near the word "Braking" indicate the start and finish of braking action), move to the outside of the turn, and re-establish your lean. This ends up being a double-apex turn. Not an approach to be strived for, but a useful and wise move if you've made (and can quickly recognize) the mistake of diving toward the inside too soon.

[tallman]

Some of us can do all three,

 

 

 

 

 

 

 

 

 

 

 

 

 

in the same turn.

[Twisties]

 

 

Just to be clear, in the green line in your diagram Mitch, the apex occurs at the point labeled "Green: Add Throttle", and this is in the middle part of the road cross-section about three-quarters through the curve.

 

In the diagram Leikam supplied in this thread the line labeled "late apex" the point labeled apex is the point of closest approach to the fog line, not the slowest point in the turn where lean angle is highest. The trajectory at the point labeled apex in this representation is actually rather flat. The apex in this diagram is actually a point just after the point labeled "Late turn in point".

 

Both late turns show a similar line, but the differences in labeling are confusing to any that are unfamiliar with these concepts.

 

Jan

 

 

[Bullett]

Hey, thanks y'all. David, I found your explanation concise and clear. Leikam and Mitch, the diagrams are great and very helpful. I appreciate everyone's willingness to share their experience and knowledge. And Tom, if you can set up the contest, let us know.

[Firefight911]

View this video for a PERFECT example of why sitting up is not ideal.

 

It is completely irrelevant that this occurred on a race track. People need to detach a "race" track from the Sunday trophy seekers to a "race" track used to develop street survival skills.

 

Many things are going wrong with this rider; bad line selection, horrible body positioning, a clear desire to put a knee down, stiff arms, etc. but the point of this video is to show that even with the other variables, had the rider had proper body positioning - kiss the mirrors - he would not have run out of lean angle, and used the bike to lever the tires off the ground.

 

[russell_bynum]

No, if I meant "kiss the mirror", I would have said that.

I'm talking radical body shift, hanging off, knee dragging, race bike (set up perfectly for that track and rider) technique applied in an instant to a sport touring bike as an attempt to salvage a dangerous situation.

 

Tim, nobody's talking about that. We're talking about "kiss the mirrors". That doesn't require lots and lots of training...it's very easy to learn to do, and it doesn't bring with it the disadvantages of a full "hanging off" position.

 

We see track racers go down in every (almost) race.

 

So? Racers are intentionally riding as close to the limit as possible. Mistakes often result in crashes because there's so little margin to work with. We're talking about street riding where the pace is such (or should be such that you have much more margin to recover from mistakes.

[tallman]

Well, we can't all ride like Rossi.

http://www.youtube.com/watch?v=Sy_rR_VZOFQ&feature=related

[Firefight911]

Well, we can't all ride like Rossi.

http://www.youtube.com/watch?v=Sy_rR_VZOFQ&feature=related

 

That's actually a pretty good video. It shows a lot.

 

You can see he went in hot to the corner, deeper than the race line, trail braked into said corner, slid front end under braking, slid rear under braking, and performed a classic low side.

 

All the time being completely composed and then along for the ride.

[motorman587]

You seem to be very focused on the fact that sitting up straight is what you were taught. So much so, in fact, that you refuse to even acknowledge the benefits of leaning to the inside, which have been delineated several times now; you dismiss it all with a wave of the hand and a declaration of "that's not what I was taught." It's become a point of dogma for you, rather than a rational discussion.

 

Other posters seem to believe this discussion is civil. I have been taught to hang of from Kevin Schwantz in 2002 at a racing school. And that is I believe hanging off should be, at a track. Our bikes, LT RT etc........are made to sit up straight. I feel that when you shift from side to side you are up setting the COG.

 

John, you're missing the whole point, and I'm starting to wonder whether it's deliberate. As I have admitted previously, there were many things I did wrong on that turn - but leaning off to the inside was what kept me from low-siding, in spite of all I did wrong; had I not been leaning off, I would probably have been in the weeds.

 

And I think that sitting up straight you would of been fine. You still had about 6 feet of road left to the right. I am sure you could low side by leaning off as sitting up straight if you max out the lean angle. I would like to know what the real difference of the angle would be beside pictures????

 

Do you disagree that leaning to the inside during turns confers several safety advantages (when compared to sitting straight up)?

 

No, one is you are shifting from side to side changing the COG, which in turn up set your tire patch. Don't have to pull ourself forward when leaning forward??? Does that not have some input on the tire patch/suspension vs sitting up straight not putting any body movement in the turn??

 

Maybe we could during BRR set up a video camera, video the two different methods (Friday) and then have a "civil" discussion (Saturday) at dinner.

[russell_bynum]

 

Other posters seem to believe this discussion is civil.

 

Mitch didn't say you weren't being civil, he said you weren't being rational.

 

I have been taught to hang of from Kevin Schwantz in 2002 at a racing school. And that is I believe hanging off should be, at a track. Our bikes, LT RT etc........are made to sit up straight.

 

1. Nobody is talking about hanging off. We're talking about keeping your butt parked in the middle of the seat at moving your upper body to the side ("Kiss the mirrors"). That gives most of the benefits of hanging off (minimize lean angle for a given speed and line) without the disadvantages (it's hard to learn to do well, it is tiring, etc).

 

2. The physics that cause a race bike to use less lean angle for a given speed/line are the same physics that apply to Harley cruisers, Vespa's, RT's, etc.

 

 

And I think that sitting up straight you would of been fine.

 

Do you deny that leaning off to the inside of the turn decreases lean angle?

 

I am sure you could low side by leaning off as sitting up straight if you max out the lean angle.

 

Naturally. And that's the whole point. leaning off to the inside results in less lean angle for a given speed and line.

 

I would like to know what the real difference of the angle would be beside pictures????

 

Hopefully someone can find them...I remember some shots from an early RideSmart class that showed the lean angle of the camera bike (with the rider kissing the mirrors) vs the lean angle of the bike being filmed (with the riding sitting up straight). Both bikes were on the same line at the same speed.

 

 

Maybe we could during BRR set up a video camera, video the two different methods (Friday) and then have a "civil" discussion (Saturday) at dinner.

 

This has already been done...hopefully someone can find those pictures. I think you'll be surprised by the difference.

[Twisties]

 

 

Just to be clear, in the green line in your diagram Mitch, the apex occurs at the point labeled "Green: Add Throttle", and this is in the middle part of the road cross-section about three-quarters through the curve.

 

In the diagram Leikam supplied in this thread the line labeled "late apex" the point labeled apex is the point of closest approach to the fog line, not the slowest point in the turn where lean angle is highest. The trajectory at the point labeled apex in this representation is actually rather flat. The apex in this diagram is actually a point just after the point labeled "Late turn in point".

 

Both late turns show a similar line, but the differences in labeling are confusing to any that are unfamiliar with these concepts.

 

Jan

 

 

Geez, been waiting all day while I was at work and couldn't post for someone to correct me. Guess I'll have to do it myself. I was confused, oh yeah, and wrong too.

 

The apex is the point of closest approach, so Liekam's diagram is labeled correctly. In the late apex turn however, the point at which the slowest speed and highest lean angle is reached is well before the apex.

 

 

[90%angel]

I think you'll be surprised by the difference.

 

I know I was. When I first started to really get the kiss the mirrors concept, I leaned the bike over, then put my body down. Without even trying, the bike just naturally decreased lean angle. The more I got my upper body down, the less the bike leaned over. I didn't even have to try...it just happened. Maybe it's more pronounced on an RS, but it was pretty cool.

 

 

[Twisties]

I think you'll be surprised by the difference.

 

I know I was. When I first started to really get the kiss the mirrors concept, I leaned the bike over, then put my body down. Without even trying, the bike just naturally decreased lean angle. The more I got my upper body down, the less the bike leaned over. I didn't even have to try...it just happened. Maybe it's more pronounced on an RS, but it was pretty cool.

 

 

It's pretty cool indeed!

 

Can anyone address the timing of the lean? I have tried it where I lean early, where I lean increasingly as I enter the turn, up to the point of adding throttle, and where I lean later just as I'm about to hit the point of maximum lean angle.

 

At this point, if I'm on my game, I'm typically leaning increasingly as the turn forces are increasing, e.g. the second scenario above. This seems to stabilize the bike and reduce chasis movement, resulting in a more constant lean angle throughout the turn.

 

Jan

[Limecreek]

Other posters seem to believe this discussion is civil. I have been taught to hang of from Kevin Schwantz in 2002 at a racing school. And that is I believe hanging off should be, at a track. Our bikes, LT RT etc........are made to sit up straight. I feel that when you shift from side to side you are up setting the COG.

 

Hi John - Have you ever snow skied or watched snow skiing on video? What does the skier do to execute a stable turn? He moves his weight to the inside of the turn. The faster the entry the more he will shift his weight to the inside of the turn. If he doesn't shift his weight to the inside he will need to tilt his skis further and further to the inside to the point where he will lose his purchase on the snow and low side.

 

Motorcycles, including RT's, work in the same way. If you choose to sit straight up in the turn, you must lean the bike over more than you would if you move your torso (weight) to the inside. The faster the entry speed the more lean angle you'll need. In the case of sitting bolt upright, you eventually run out of lean angle and down you go.

 

 

[motorman587]

Couple of points that I have made which are being missed. You are all focused on the lean angle to make a smooth controlled corner. I understand about the lean angle. Again about races who lean off to get the max. lean angle out of a motorcycle because they need to win. I also understand about kissing the mirrors, I think.

We are street riders. You need to make a nice smooth control turn in a turn. You need not to make any movement. Never have taken a RideSmart class, when do you move your upper body? Beginning of the turn??? And when do you sit up straight again, at the end?? To me this movement, left or right, will up set the suspension which in turn could up set the your tire patch?? No??

Why do I have to worry about max lean angle?? I would only have to worry if I rode 100% on the street. Each rider should ride 80%, and have at lest 20% in case of a problem. IE, proper entry speed and set up.

[Albert]

Each rider should ride 80%, and have at lest 20% in case of a problem. IE, proper entry speed and set up.

 

I think this is the point. By using the technique being described (same road, same speed, same bike, etc), an 80/20 ride becomes a 75/25 ride. Yes, I'm making the second number up but it will be an improvement in margin nonetheless. As for why maximum lean angle may be important, picture the deer that wanders onto the road while you're mid turn. I'll take the extra 5% or whatever it amounts to if it gets me around him.

[rocks]

Each rider should ride 80%, and have at lest 20% in case of a problem. IE, proper entry speed and set up.

 

I think this is the point. By using the technique being described (same road, same speed, same bike, etc), an 80/20 ride becomes a 75/25 ride. Yes, I'm making the second number up but it will be an improvement in margin nonetheless. As for why maximum lean angle may be important, picture the deer that wanders onto the road while you're mid turn. I'll take the extra 5% or whatever it amounts to if it gets me around him.

 

Excellent point!

 

(Russell)Ooh...this is a good point. The mantra should probably be Slow. Look. Press. Release. Roll. Countersteering should be a finite press/release. Lots of riders press, and the counter that pressure with their other hand, which results in them being tight on the bars. If the bike is properly balanced (a factor of throttle control and body position), you should be able to let go of the bars and the bike would maintain it's arc until it ran out of gas and fell over. If you're having to hold pressure in the turn to maintain your line, there's something not right.

 

The second tolast line of this(you should be able to let go of the bars and the bike would maintain it's arc until it ran out of gas and fell over) hit home with me seems an easy way to "feel" correct weight management... need to concentrate on my next ride... I think I'm doing it but...

 

 

[russell_bynum]

Why do I have to worry about max lean angle?? I would only have to worry if I rode 100% on the street.

 

Ah HA!!!

 

And what's 100%?

 

Does 100% mean you're at the hairy edge of traction and another degree of throttle opening or lean angle and the bike slides? Does it mean the bike's already sliding but you're managing the slide?

Does it mean you're nowhere near the traction limits of the bike but you're running at a pace that is as fast as your brain can process things without making mistakes?

 

Can 100% change?

 

What if you think you're at 80%, but something happens you weren't expecting and that pushes things to 105%?

 

 

I rode the RS to work today and decided to play with this. I've got a couple of very long constant-radius corners on my commute and I happened to get to them without traffic. My feet were on the pegs with my instep on the peg, and my toes dangling lazily. I entered the corner, dropping my upper body in (kiss the mirrors) as I leaned the bike in. Once I got the bike established on my desired line and with the throttle balanced to maintain speed, I moved my upper body back upright. By the time my head was on the centerline of the windshield, the toe of my inside boot was dragging. I dropped my body back down and my boot gradually came up off the ground. I sat back up and down it went again. I came out of that corner, had a short little straight, then dropped into the next corner...an almost identical very long constant radius corner, but going the other direction. I did the same thing, with the same results.

 

Clearly, this shows that the "kiss the mirrors" body position will decrease lean angle (and therefore increase margin) for a given speed and arc.

 

I also noticed that when I was upright, I had to keep pressure on the bars to keep the bike on line, vs "Kiss the mirrors" where the bars were totally light in my hands...I could have set the throttle lock and taken my hands off the bars and the bike would have stayed on line.

 

 

One thing I did notice...when I'm going through a busy intersection, like if I'm making a left turn through a busy 6-lane street, I sit more upright because that allows me to turn my head much more easily to keep an eye on what's going on with the other traffic. So...that would be a drawback of kissing the mirrors and an advantage of sitting upright...it's easier to keep an eye on traffic when you're sitting more upright.

[leikam]

When do you move your upper body? Beginning of the turn??? And when do you sit up straight again, at the end?? To me this movement, left or right, will up set the suspension which in turn could up set the your tire patch?? No??

 

You move your upper body inside at the beginning of the turn and straighten up at the end. And, yes, this does have an effect on the suspension and moves the center of gravity which is why it should be done smoothly and well before you're anywhere near the limits of traction. Nobody's advocating violent movements at critical moments. In my experience, leaning in does not reduce traction which seems to be a big concern for you in considering this. In fact, it ensures better traction through the turn by reducing the lean angle needed regardless of entry speed. The result of this is that the tire is further from its edge and the suspension has a better chance to work against bumps and keep the tire on the road.

 

Ideally this is all done very fluidly as the CofG of the bike+rider mass is already changing as one enters the turn. The relation of the CofG to the contact patch of the tires is dynamic in a turn. The technique of leaning in is just a way to actively participate in that change and thereby have some control over it and experience with the dynamics.

[Scriber]

Why do I have to worry about max lean angle?? I would only have to worry if I rode 100% on the street. Each rider should ride 80%, and have at lest 20% in case of a problem. IE, proper entry speed and set up.

 

Three weeks ago I was traveling the North Cascades Hwy. Headed into a series of twisties that were posted at 30 mph, all of which were blind corners. I was riding at far less than 80% of my capability. I was not traveling quickly because of the tourist traffic. However, I consider inside positioning ("kissing the mirrors) an insurance policy, so I was well inside the center line of my bike.

 

Suddenly, an oncoming jeep is 3/4 into my lane. Had I been in a car we would have collided due to the added width of a car. Fortunately, I had lots of lean angle to spare. I tightened my line by cashing in some of the extra lean angle I had purchased with my inside position.

 

Blind corners, corners with turnouts that spew gravel in the road, damp areas in shaded corners... on all of these I take out an insurance policy in the form of an inside body position to conserve lean angle. Come to think of it, I always take an inside body position on anything resembling a tight corner. It's a great way to build good habits.

 

Now, I'd love it if we could have a similar discussion on downshifting technique.

[motorman587]

Wow...........not one negative post on Motorman. But then not all the key players have posted either. I have motor training on Monday and I am going to take a camera. I will take a picture of me "kissing the mirrors" and "sitting up straight", in a curve. I will post, somebody going to help with smugmug.

[motorman587]

Now, I'd love it if we could have a similar discussion on downshifting technique.

 

Lets start, what is the question??? Roll off, squeeze in the clutch, press down with the foot and eeeeeeeeeeeeeeeeeeeease out on the clutch.

[Firefight911]

Now, I'd love it if we could have a similar discussion on downshifting technique.

 

Lets start, what is the question??? Roll off, squeeze in the clutch, press down with the foot and eeeeeeeeeeeeeeeeeeeease out on the clutch.

 

If you would like to use your clutch as a brake, that would work fine.

[Firefight911]

I will post, somebody going to help with smugmug.

 

Email them to me and I will post them right away!

[russell_bynum]

I will post, somebody going to help with smugmug.

 

Email them to me and I will post them right away!

 

John,

Make sure you're on the same line and speed, just to keep everything equal.

[Firefight911]

John,

Make sure you're on the same line and speed, just to keep everything equal.

 

Darn you!! There went a perfectly tasty, cold Coke Zero!

[David]

[motorman587]

 

If you need to get off your chest PM me............

[motorman587]

I will post, somebody going to help with smugmug.

 

Email them to me and I will post them right away!

 

John,

Make sure you're on the same line and speed, just to keep everything equal.

 

I will attempt to be fair..............

[Jeepster]

 

I will attempt to be fair..............

 

 

 

 

[Twisties]

Wow...........not one negative post on Motorman. But then not all the key players have posted either. I have motor training on Monday and I am going to take a camera. I will take a picture of me "kissing the mirrors" and "sitting up straight", in a curve. I will post, somebody going to help with smugmug.

 

Looked in Monday's S*** and didn't see anything... so I guess it didn't go too badly....

 

Jan

[TyTass]

My two cents to all readers:

 

My thanks go to Russell, Mitch, & David for their persistence in this post. The viewpoint the three of them are trying to illuminate is not a matter of preference in riding styles – it is a matter of physics. And it is too important to allow anyone citing personal preference or some "other" more competent authority as cause for adherence to a riding style that cannot be agrued in physical terms to do so unchallenged. While opinions aren’t necessarily equal when it comes to physics either, we aren’t talking about extremely complex physics here. While most of this really is about ephemeral (seat of the pants) physics, it does however bear thinking through a bit and not simply accepting someone's word's or qualifications.

 

These guys (and others) have brought some very important and useful information to this discussion to this post. I am again reminded of one the most important reasons I joined and remain part of this Board – improving my skills. Though I hadn't read this thread prior to leaving last Friday morning for RideSmart in Morganton NC, having now attended the RideSmart course, I can say with certainty that I have "experienced" the reasons why "kissing the mirrors" is a far more effective and safe practice for taking turns.

 

BTW: RideSmart is not a course where a style of riding is taught. Attendees are not asked to accept anything based on the authority of the instructor. The course rather cleverly has attendees riding in various positions to understand how the bike behaves in turns under different systems of control. These positions illustrate most all of the forces involved in turns (at speed), how the bike responds to those forces, as well as the ones we induce into the bike. At varying points towards the end of the course (and sometimes after) the “light bulb” turns on as attendees grasp just how smoothly and effectively a bike is cornered by “kissing the mirrors” (controlling with body lean as opposed to firm hand inputs). To cement it for me, all it took was one decreasing radius curve where all I needed to do was to simply pull the bike down towards my lean to tighten things up with no pucker factor. And all that despite riding over some really rough bumps. But I think the benefits of suspension of bike operating in a turn with a reduced lean angle are nearly self-evident and can be found in a number of publications that illustrates the operation of motorcycle shocks.

 

My point is the curriculum of RideSmart is completely devoted to understanding this very discussion and I heartily recommend it to anyone with some miles under them and dedication to self-improvement. If you want to significantly improve your abilities and confidence in turns, as well as dramatically increase your safety margin at the same time AND in short order ... RideSmart is the ticket.

[StretchMark]

Here's another good writeup, although a bit more extreme than our kiss the mirror concept, from our old friend David Hough (proficient Motorcycling, etc):

http://www.soundrider.com/archive/safety-skills/coming_unglued.htm

 

 

While opinions aren’t necessarily equal when it comes to physics either, we aren’t talking about extremely complex physics here.

 

Not complex at all:

Angular inertias related to wheel:

 

Thin circular hoop: I = M x R^2

Solid disk: I = 1/2 x M x R^2

 

Say you only increase the weight of the spokes of a wheel but not the rim, and treat the spokes of a wheel as a solid disk, using a front wheel in this example.

 

wheel radius = 8.5 inch (17 inch diameter wheel)

tire radius 120x70x17 = 120mm x .70 + 8.5 in = 3.3 in + 8.5 in = 11.8 in

 

wheel radius = .72 of total radius

 

Iw = angular inertial of wheel, treated as a solid disk:

Iw = 1/2 M (.72 R^2) = .26 M R^2

 

LF - FF = M LA

 

AA (angular acceleration) = T (torque) / Iw

AA = LA (linear acceleration) / R (assuming no slippage here)

LA = AA x R (left this out before)

Torque = FF x R

 

LA = (FF x R^2) / (.26 M x R^2)

LA = FF / (.26 x M)

FF = LA x .26 x M

 

So substituting in the first equation:

 

LF - FF = LA x M

LF - (LA x .26 M) = LA x M

LF = 1.26 x (LA x M)

LA = LF / (1.26 M)

 

So any weight added to a solid disk would have 1.26 times the effect. 1 lb added to to the spokes would be the same as 1.26 lbs added to a non-moving part of the motorcycle.

 

For the case of adding weight to the rim of the wheel:

 

Iw = angular inertial of rim, treated as a thin hoop

Iw = M (.72 R^2) = .52 M R^2

 

LF - FF = M LA

 

AA (angular acceleration) = T (torque) / Iw

AA = LA (linear acceleration) / R (assuming no slippage here)

LA = AA x R (left this out before)

Torque = FF x R

 

LA = (FF x R^2) / (.52 M x R^2)

LA = FF / (.52 x M)

FF = LA x .52 x M

 

So substituting in the first equation:

 

LF - FF = LA x M

LF - (LA x .52 M) = LA x M

LF = 1.52 x (LA x M)

LA = LF / (1.52 M)

 

So any weight added to a hoop with .72R radius would have 1.52 times the effect. 1 lb added to the rim would be the same as 1.52 lbs added to a non-moving part of the motorcycle.

 

Basically the effect will be 1.00 + the coefficient for angular inertia. Actual radius, doesn't matter, just the relative radius of the spokes, or wheel to the outer radius of the tire (note, that the effective radius is a bit smaller, because the contact patch deforms, but I don't think you need numbers that exact).

 

In your case, weight added to the spokes has a 1.26 multiplier, and weight added to the rim has a 1.52 multiplier. For the back wheel, the effect is less, because the tire is larger, for a 190/50/17, its 3.75 inches. This reduces wheel radius factor to .69, and weight added to spokes would have a 1.24 multiplier and weight added to rim would have a 1.48 multiplier.

 

To caculate tire height from a tire size, width / profile / diameter

 

width is given in mm, profile is a percentage, and diameter doesn't matter

 

Tire height in inches = width x profile / 2540

 

Total diameter = diameter + 2 x tire height in inches.

 

And Mitch...if you find any problems with the formula, contact the guys I plagiarized from :

http://www.physicsforums.com/showthread.php?t=221863