Learning to trust the lean??

[zbassman]

Hi,

 

I have a 2000 R1100RT. I've had it for a few months now, and have put about 5,000 miles on it. Before this I rode a Suzuki Volusia for about 3 years and put 33,000 miles on it. Before that was a 1974 Honda CB450, but that was 20+ years ago.

 

Anyhow, for some reason recently I've developed this irrational fear of leaning in to curves going to the right. Its just to the right. Going left, no problem. I feel totally comfortable leaning to the left.

 

But to the right I keep feeling like the bike is going to slide out from under me. Or its just going to topple over. This is at any speed. Going home last night I entered a right hand sweeping curve at about 50MPH and had to will myself to accelerate through the curve and increase my lean angle. I exited the curve at 55 or so. But in the past I've entered that curve well over 50 and exited over 60.

 

Intellectually I know the bike can handle much more lean angle then I'm asking. The tires are in good shape, with just 5,000 miles on them. The PSI is set to the BMW owner manaul specs. I'm a big guy so I've got the preload set up as if riding two-up.

 

I'm about half tempted to gear up this weekend and go out and really push myself in leaning to the right, over and over and over until I trust it again.

 

On the other hand I think I might be better to take it a little at a time and let the trust build up over the next month or so of riding.

 

Anyone have any tips, strategies, excercises, etc. I can try?

 

Any thoughts greatly appreciated.

[upflying]

I also turn easier to the left than I do to the right. It may have something to do with inner ear and our sense of balance. I overcame it with some low speed parking lot practice. Keep your head and eyes up and level with the horizon while leaning.

[russell_bynum]

I'm about half tempted to gear up this weekend and go out and really push myself in leaning to the right, over and over and over until I trust it again.

 

I strongly recommend against that. The street isn't the place to push yourself.

 

Usually, when I have a problem turning one direction but not the other, it is a body position issue. Make sure you're using good body position, and your position is consistent going both directions.

 

Make sure you are not cross-controlling the bike...pushing it down under you while you stay upright. That's a really common thing when you are affraid. Your brain sees the ground and says "Don't go there", so you stay up and you push the bike down under you. That eats more lean angle than necessary. It might feel better, but it isn't.

 

Here's an example of what cross-controlling the bike looks like:

 

 

Start with the Master Yoda Riding Position You can get into and practice that position with the bike on the center stand.

 

Now...put a little piece of electrical tape on the top edge of your windscreen right on the center line.

 

When you're in a corner (starting from the Master Yoda position), drop you upper body forward, down, and in towards the inside of the corner. Think of it as if you were trying to kiss the inside mirror.

 

Here's an example:

 

 

What's the tape for? It makes a great guide to tell if you're cross controlling. Your head should always be inside of that tape when the bike is turning.

 

Play with this by making GENTLE easy turns in a large empty parking lot.

 

Your goal is to make sure you're in the same relative position going both directions, and if not, figure out what's different and how you can change that.

[Fergie]

I think it should be a little at a time, safer. I started riding a road bike back in the late 60s and have always felt more comfortable on left turns than right turns, it’s not that I’m afraid of right turns just a little uncomfortable. I don’t ride anywhere as fast as I did 30 years ago but still have that feeling, just don’t know why. I also feel a little uncomfortable going fast down hill into a sharp corner even if I know the road well. Do not know what to really tell ya but again I think a little at a time. Don’t get over your head, or mind set, and get in trouble.

[George Brown]

A big Ditto to everything Russell said. In addition you might want to look at Lee Parks book "Total Control". If possible get signed up for a RideSmart session - keep an eye on this board for one that you could attend. I learned more in one 8-hour RideSmart event than I don't know how many videos, books and articles. The coaching did the trick. Perhaps you can find someone near you on this board who has attended one to coach you.

[MAT2CHI]

 

Anyone have any tips, strategies, excercises, etc. I can try?

 

Any thoughts greatly appreciated.

 

When I bought my new R1150RT I wanted to know just what it would do and how it would handle. So I signed up for a riding/racing school that let me ride my own bike, (that was coming to my local racetrack) and spent the entire day learning about my motorcycle and how to ride it. If you really want to overcome your fears AND become an improved rider, sign up for a class and you will thank me after you finish. Below I'm following an instructor through turn seven at Infinion Raceway on my 2004 R1150RT.

 

[Little Joe]

There are many posters on this forum with 10-20 times my mileage under their belts, so take my input with the necessary grain of salt.

 

I'm also a big guy, and even using full preload and what I perceive to be good body positioning ("kissing the mirror"), I have a serious ground clearance problem. I have grounded the right lower fairing a number of times. I have some Wilbers coming that should fix at least that issue. If you have a 2000 RT, I wonder what the total mileage on the bike is, and if perhaps your shocks are eating up some clearance.

 

The smaller radius of any right-hand curve vs. an equivalent left-hander may increase the pucker factor, as might the prospect of drifting into the oncoming lane as opposed to onto the shoulder. I do know that as I learned to trust my bike's geometry and tires, I gained confidence in applying more countersteer and throttle to get through a tight turn. I agree with all the cautions about taking it slow.

 

Also, I run Z6's, and I certainly don't have nearly the confidence in the tread at 5K miles as I do when they're new.

[Baba_ORiley]

Hi,

 

I have a 2000 R1100RT. I've had it for a few months now, and have put about 5,000 miles on it. Before this I rode a Suzuki Volusia for about 3 years and put 33,000 miles on it. ...

Exactly like you, I came from a Volusia to a R1100RT-P. On my normal ride height Volusia I happily scraped away the sacrificial slider screws under the footpegs. I regularly leaned that bike over quite far - especially for a cruiser and felt very comfortable doing so.

 

But my RT sits so much higher, with a noticeably higher center of gravity, that I don't even come close leaning it as far. Even after a year I'm still too upright and uptight, but I keep working on it.

 

 

.

[Lawman]

"Your brain sees the ground and sys "Don't go there"

 

Yup, sure does. But now I tell it to STFU..

 

Thanks Russell..

 

Do you ever teach any riding classes?

[russell_bynum]

Yup, sure does. But now I tell it to STFU..

 

That's the trick, isn't it.

 

 

Do you ever teach any riding classes?

 

I helped David teach a Ride Smart a couple of years ago up in NorCal. I need to get off my ass and do another one down here.

[11101110]

I took a MSF ERC course a couple of weekends ago and learned exactly how mych my bike leans before kissing the ground. While riding the kidney bean I did think to myself "Hey I'm closer to horizontal than vertical here and I not scraping, opps(scrape). Needless to say, the lean angle is very extreme on my RTP. May want to try and ERC before a track day.

 

On another note I was practicing in a parking lot a few nights later and realized that I can do a u turn to the right WITHIN two parking spaces without anything than the two tires touching the ground. I can't for the life of me do the same thing to the left

[Doppelganger]

Great question...great answers...thanks to all.

[Tonopah]

My issue was with left turns. Be that as it may, firstly I suggest that you take things slowly and not try to rush into a quick fix. For me, I found that I often ride the same roads with the same curves and I know what speed I can comfortably enter a given curve knowing that I'll make it through okay. I also know that I am not even beginning to challenge the envelope of what the bike is capable of. I tend to enter the familiar curve at a comfortable speed but play with accelerating faster through the curve than I did before. This builds confidence and after a while if find myself comfortable entering the curve at a somewhat higher speed. Slowly the confidence builds and so does the skill. I am 59 and back into bikes for only the last 5 years and I am acutely aware that I can no longer bounce like an 18 year old so I have been developing skills and comfort slowly! But my riding is smoother and way more comfortable that last year and the year before...

[leikam]

How do u-turns feel? When's the last time you did circles in the parking lot? You could try them one-handed.

 

You also might want to double-check your grip on the throttle. For right-hand turns, you should be able to put your forearm parallel to the bar -- leading with your elbow.

 

Sometimes tires just don't feel right and changing them brings back confidence.

 

Have you dropped the bike at a standstill yet?

[zbassman]

Thanks for all the replies.

 

One thing I noticed on the way to work this morning is: Body Position. My body position going to the right was markedly different than going to the left. I wasn't really getting in to the "kiss the mirror" position. I was sitting upright and actually leaning back some. And I was almost locking the elbow on my left arm so I was preventing the right from really pushing the grip and hampering my counter steer efforts.

 

I'm running Z6 tires and they seem to have plenty of tread left.

 

I'm going to hit the parking lot this weekend and just do some easy excercises. I haven't done that since I bought the RT.

 

I haven't dropped this bike, yet. I dropped my Vol a couple of times while doing parking lot practice.

 

Again, thanks for all the input. Some great info here.

[exwingnut]

I was almost locking the elbow on my left arm so I was preventing the right from really pushing the grip and hampering my counter steer efforts.

 

This is EXACTLY what I find to be the problem for me; I am invariably locking one elbow or the other when I notice I am having problems with getting the bike to lean.

 

Cross controllin/counterleaning, whatever! What ever you call it it makes leaning the bike over ner impossible.

[David]

Set up a video camera on a tripod in the parking lot and do circles in both directions. Then analyze the video and you'll see the problem, probably. Or post it here and we'll be glad to criticize it.

[ScottM]

Lee Parks "Total Control" one day course cured me of that same problem. Creeps back now and then but you'll learn the skills and techniques to self-correct

Scott

[Mark K]

Make sure you are not cross-controlling the bike...pushing it down under you while you stay upright. That's a really common thing when you are affraid. Your brain sees the ground and says "Don't go there", so you stay up and you push the bike down under you. That eats more lean angle than necessary. It might feel better, but it isn't.

 

 

That is a great description! I've found it difficult to describe that verbally to other riders.

 

I did that for years and wondered why it was that although I could corner well (I thought) it took a great deal more effort and lean angle than I thought it should. It just didn't feel natural or comfortable, and it was sometimes difficult to hold my line through the sweepers like I was fighting the bike. Turns out I was!

 

Body position is everything. Well said and thank you for the visual examples.

[NEOHMark]

+1 to Russell and body position.

 

You can actually practice at home - not even on a bike.

 

Take a door - any door in your house - and open it 45 degrees. Grab one door handle with your left hand, the other with your right. Line up your body with the 'vertical' of the door.

 

Wanna practice going left? Lean your upper body around the door to the left. Wanna practice to the right? Lean your upper body around the door to the right. You can take that visualization, and the muscle memory, with you right onto the bike.

[ShovelStrokeEd]

Another point on this and Russell has mentioned it before.

 

Keeping loose on the bars. Once your body position is right, you need zero bar pressure to maintain lean angle and arc around the turn. I was playing with this on some high speed sweepers the other day and found I could let go of the bars entirely (I have a Throttlemeister) and the bike would continue to carve the turn with no further help from me. I'm sure it caused some consternation to the group of HD's I passed while going over Mt. Eagle as I went by them on the inside with at least 20 mph in hand and waved to them with both hands.

[russell_bynum]

Another point on this and Russell has mentioned it before.

 

Keeping loose on the bars. Once your body position is right, you need zero bar pressure to maintain lean angle and arc around the turn. I was playing with this on some high speed sweepers the other day and found I could let go of the bars entirely (I have a Throttlemeister) and the bike would continue to carve the turn with no further help from me. I'm sure it caused some consternation to the group of HD's I passed while going over Mt. Eagle as I went by them on the inside with at least 20 mph in hand and waved to them with both hands.

 

Right. That's a key part of the Master Yoda Riding Position.

 

I do the "no hands" too. Or at least...I did when I had a throttle lock on the RT.

 

I used to ride for miles with my hands on my knees...straights, hills, corners, whatever. When you're forced to steer the bike with your body weight like that, you really get a feel for what a difference it makes. Counter steering is by far the most efficient way to get the bike turned quickly and precisely, but body weight can really have an impact on it as well. It's like the trim on an airplane. You don't need the trim to fly the plane...but if you don't use it, you'll be fighting the plane and working much harder than you need to.

[IanW]

Have a look here:

ttp://forums.superbikeschool.com/index.php?showtopic=111

Ian

[IanW]

Try again:

http://forums.superbikeschool.com/index.php?showtopic=111

Ian

[Wyn]

Another point on this and Russell has mentioned it before.

 

Keeping loose on the bars. Once your body position is right, you need zero bar pressure to maintain lean angle and arc around the turn. I was playing with this on some high speed sweepers the other day and found I could let go of the bars entirely (I have a Throttlemeister) and the bike would continue to carve the turn with no further help from me. I'm sure it caused some consternation to the group of HD's I passed while going over Mt. Eagle as I went by them on the inside with at least 20 mph in hand and waved to them with both hands.

 

Hee, hee!!

[exwingnut]

+1 to Russell and body position.

 

You can actually practice at home - not even on a bike.

 

Take a door - any door in your house - and open it 45 degrees. Grab one door handle with your left hand, the other with your right. Line up your body with the 'vertical' of the door.

 

Wanna practice going left? Lean your upper body around the door to the left. Wanna practice to the right? Lean your upper body around the door to the right. You can take that visualization, and the muscle memory, with you right onto the bike.

 

Great idea, just visualizing it will help to understand the mechanics of leaining into the direction you are leaning.

 

You might even try it sitting on a chair in front of the door to get a better feel of the body mechanics needed to do this easily on the bike.

[Twisties]

Yup, sure does. But now I tell it to STFU..

 

That's the trick, isn't it.

 

 

Do you ever teach any riding classes?

 

I helped David teach a Ride Smart a couple of years ago up in NorCal. I need to get off my ass and do another one down here.

 

IN.... er uhhmmm depending when it is.

 

In addition to what has been said already, elbows loose, grip on bars loose, relaxed body, use foot pegs, and most importantly: Look all the way through the turn to the exit. You probably know this, but perhaps you are not doing one of these things on right turns. Check off all the above in your practice sessions.

 

Jan

[Survived-til-now]

Just approaching this from a different angle (and a minor one at that for I am sure all the riding advice is good stuff and more relevant - I'm definitely going to try the tape on the screen that Russell suggests to check for over-controlling)

 

Tyre pressures to BMW spec's - my R1200RT 2005 handbook says 32 psi front and 36 psi rear for solo riding. That is way too low and makes the bike wallow around. Tyre manufacturer says 36 psi front and 40/42 rear - handling is much better and crisper. Same thing on my R1150RT - I always upped the pressures from the handbook.

 

You say your tyres are in good nick at 5000 miles. You could be doing different riding but at 5000 miles mine are squared off and on the last change I noticed the front was worn more on one side than another.....

 

I'm not saying these differences will affect your riding to the degreee you describe but I guess they are not helping the situation.

[Joe Frickin' Friday]

Keeping loose on the bars. Once your body position is right, you need zero bar pressure to maintain lean angle and arc around the turn. I was playing with this on some high speed sweepers the other day and found I could let go of the bars entirely (I have a Throttlemeister) and the bike would continue to carve the turn with no further help from me.

 

OK, so here's a question for ya. I finally pieced it together in Torrey this spring, and experimented with it more this past weekend at El Paseo (the first chance I've had since Torrey to play on fun roads). When I'm paying attention, I can lean off to one side and unload the bars.

 

Well, almost. I'm leaning far enough off so that if I were to take my hands off of the bars, the bike would turn in tighter; I'm actually having to maintain a left push to keep from running off to the inside of a right turn.

 

So what's the appropriate amount of body lean? Do I want to lean as much as possible, so as to maximize ground clearance and keep the suspension as vertical as possible? Or do I want to lean just enough to achieve zero steering effort once I've entered the turn?

[ShovelStrokeEd]

Mitch,

It's a feel thing. If the bike tightens up when you let go of the bars, something is off, likely you are too far inside. What I tend to do is set my body position well before the turn using observation about what the turn is doing as to how far. Then, as I turn the bike in, I start to ease the pressure on the bars and adjust my upper body according to what the bike is wanting to do.

 

You don't want to be putting counter pressure on the bars to keep from tightening the turn, it confuses the bike. The advantage of using your upper body for all this rather than the lower is that moving it around, so long as you are using your core muscles to control the position, hardly bothers the bike at all. I often find I have under estimated the amount I need to be inside and just dive in there a little further till the bike feels settled. You can make major corrections this way and the bike doesn't seem to notice much, if at all.

[George Brown]

Mitch,

It's a feel thing. If the bike tightens up when you let go of the bars, something is off, likely you are too far inside. What I tend to do is set my body position well before the turn using observation about what the turn is doing as to how far. Then, as I turn the bike in, I start to ease the pressure on the bars and adjust my upper body according to what the bike is wanting to do.

 

You don't want to be putting counter pressure on the bars to keep from tightening the turn, it confuses the bike. The advantage of using your upper body for all this rather than the lower is that moving it around, so long as you are using your core muscles to control the position, hardly bothers the bike at all. I often find I have under estimated the amount I need to be inside and just dive in there a little further till the bike feels settled. You can make major corrections this way and the bike doesn't seem to notice much, if at all.

Well articulated Ed. I am finding the same things as I work myself up the learning curve (pun intended).

[GeeTee]

Wow! Outstanding Q & A. Thanks to all. Only one thought to add to the O.P.

 

Some days I just don't have 'it'. No sense pushing a bad position.

 

Some days I really have 'it'. Those days become memorable.

[thew]

This is coming from a relitively new rider, I've only had my bike for 2 months but rode my Dad's on and off for 4 years. This weekend I rode about 700 miles and made a crucial step (in my opinion) with the advice from the service manager at Holt BMW. We were talking about weight on the pegs as a method to initiate lean, rather than countersteering, and it really works. I've always utilized the look, push, lean, and roll style of coutering, but now feel much more confident in a tight/fast corner shifting my weight off the seat just a bit, and really pushing with the inside foot right on the ball. I can feel the bike just "fall" over to the lean. I've also been playing around with using my knee to push down on the fairing ('01 11RT) which helps a lot. My new z6's with less than a G help out for sure too. Much better than the old cop tires that had no cornering wear.

 

Prior to this weekend I'd never scraped the peg protector screws and now have a nice diagonal with a sharp point on the L, and knocked off the R. Looking through the corner is huge for me too, but still, going R seems a little scarier. I think it's that I'd rather hit the guardrail than an on coming car, and the entry angle seems to have more room when going L for some reason. Once I scraped, I felt so much better/comfortable with the mystery gone and now really trust the bike and tires so much more. I wouldn't encourage someone to scrape that's not ready, but once you do, you'll probably have a much better understanding of your and the bike's capabilities.

 

Just my 2 cents

 

A young novice,

Mathew

[russell_bynum]

This is coming from a relitively new rider, I've only had my bike for 2 months but rode my Dad's on and off for 4 years. This weekend I rode about 700 miles and made a crucial step (in my opinion) with the advice from the service manager at Holt BMW. We were talking about weight on the pegs as a method to initiate lean, rather than countersteering, and it really works. I've always utilized the look, push, lean, and roll style of coutering, but now feel much more confident in a tight/fast corner shifting my weight off the seat just a bit, and really pushing with the inside foot right on the ball. I can feel the bike just "fall" over to the lean. I've also been playing around with using my knee to push down on the fairing ('01 11RT) which helps a lot. My new z6's with less than a G help out for sure too. Much better than the old cop tires that had no cornering wear.

 

Sorry, but countersteering is still the best, quickest, most precise, and most efficient way to make the bike lean.

 

Footpeg pressure, body weight shift, etc can be used to turn the bike, but it is very inefficient and not precise. It's good to use along with countersteering (as Ed outlined above), but by itself is not good.

 

I'd also suggest leaving your butt centered in the seat and just shifting your upper body around.

The reasons for that are:

1. Most of your weight is in your upper body anyway

2. It is easier to move your upper body than your lower body

3. It is harder to move your lower body without upsetting the bike.

4. You will be slower to react if you need to suddenly change directions if you have to drag your lower body up and across the seat.

[thew]

 

 

Sorry, but countersteering is still the best, quickest, most precise, and most efficient way to make the bike lean.

 

Footpeg pressure, body weight shift, etc can be used to turn the bike, but it is very inefficient and not precise. It's good to use along with countersteering (as Ed outlined above), but by itself is not good.

 

I'd also suggest leaving your butt centered in the seat and just shifting your upper body around.

The reasons for that are:

1. Most of your weight is in your upper body anyway

2. It is easier to move your upper body than your lower body

3. It is harder to move your lower body without upsetting the bike.

4. You will be slower to react if you need to suddenly change directions if you have to drag your lower body up and across the seat.

 

 

Russell,

I definitley agree with you on those four points and that style of riding for sure isn't what I'd recommend as the standard. I rode that way only some, and it's definitley more work and more demanding. I did notice too, that if done poorly I coul engage or disrupt the suspension- not good. I'd still hold though, that as a way to learn the bike, it might be a good thing to try. Countersteering after that felt so good for sure. Just another tool in the arsenal...

[russell_bynum]

I'd still hold though, that as a way to learn the bike, it might be a good thing to try. Countersteering after that felt so good for sure. Just another tool in the arsenal...

 

Oh, OK. I agree with that. I used to set my throttle lock and ride for miles without touching the bars. I agree that it is a very good thing to do to teach you how body weight, peg pressure, etc changes how the bike responds.

[Wooster]

I'm about half tempted to gear up this weekend and go out and really push myself in leaning to the right, over and over and over until I trust it again.

 

On the other hand I think I might be better to take it a little at a time and let the trust build up over the next month or so of riding.

 

More of the latter and less of the former. Incrementally exposing yourself to right handers for year or so will diminish anxiety. Ten Years After, you'll see lefts and rights as same.

 

Wooster w/o left/right prejudice

[nrp]

Why are you accelerating in turns? Because the Rider Course told you too? Why? I think that's so much BS. (Comments will be accepted from anyone!)

 

Foot peg pressure? Let's ride two-up and you can have the footpegs (or whatever) - as long as I can have the handlebars.........!

 

My speculation on the greater fear of right hand turns is the positioning etc mentioned above by others but maybe also the poorer throttle control you may have when your wrist is crooked over. It could even be unique to your particular physiology.

[russell_bynum]

Why are you accelerating in turns? Because the Rider Course told you too? Why? I think that's so much BS. (Comments will be accepted from anyone!)

 

If you are on the gas, the suspension is more settled, you have better ground clearance, and you can keep the bike's weight distributed 60/40 rear/front, which is important because that's about the difference in the size of the contact patches. In other words: Being on the gas gives you better traction.

 

Why do you think it is BS?

 

 

 

Foot peg pressure? Let's ride two-up and you can have the footpegs (or whatever) - as long as I can have the handlebars.........!

 

Are you suggesting that it isn't possible to influence the bike by moving your weight around?

[Wooster]

My speculation on the greater fear of right hand turns is the positioning etc mentioned above by others but maybe also the poorer throttle control you may have when your wrist is crooked over. It could even be unique to your particular physiology.

 

Perhaps, perhaps not. It's interesting to note the Indianapolis 500 race is run counter clockwise (four lefts, no rights), oval dirt tracks too.

I recall having some right turn trepidation in undergraduate school. Riding my 250cc two stroke street bike on rt 202 in W. MA had me relish the lefts yet tense-up in right turns. That was thirty-some years ago and those mixed feelings, i.e., right vs. left turns are only memories. Just the same, I empathize with the OP (Olla zbassman) and respectfully recommend slowly increasing speeds in the dreaded right handers. It took me years to develop my lackadaisical riding attitude (sort of like Alfred E. Newman, "What, me worry ?") and I suspect the OP's skills and confidence will grow with time.

 

Wooster

 

"The past is a foreign country, they do things differently there." (some 19th century English author)

[nrp]

"If you are on the gas, the suspension is more settled, you have better ground clearance, and you can keep the bike's weight distributed 60/40 rear/front, which is important because that's about the difference in the size of the contact patches. In other words: Being on the gas gives you better traction."

 

I assume you mean a "settled" suspension is a compressed suspension? If so, acceleration of a chain drive bike will cause the front fork to extend and the rear to compress in most bikes due to overturning moment.

 

In old BMW bikes both the rear and the front suspensions will extend under acceleration.

 

In the BMW ParaLever etc suspensions, the rear will extend much less under acceleration (if at all) due to the kinematics of the 4 bar linkage supporting the final drive. The front will still extend under acceleration due to overturning moment, and will only resist compression when the front wheel is braking.

 

In summary, different bikes do different things under acceleration and braking.

 

However all accelerations cause the weight distribution (the normal or perpendicular tire patch force) to become unmatched to the necessary lateral force of each wheel for maneuvering. In the extreme case, heavy acceleration causes the front wheel to lift causing the rider to likely lose control.

 

As an example, in a minimum traction situation such as ice, any attempted acceleration will reduce the lateral force capability of each wheel, with the front wheel being the first to slide out laterally while accelerating.

 

Tire patch area has little to do with horizontal traction force possibilities. Rather it is the normal force (i. e. the perpendicular force) that determines the traction limit. It is important in a marginal situation to not waste traction trying to accelerate longitudinally and in rare cases maybe not to even brake.

Adding a longitudinal force at the rear wheel tire contact patch can't improve the rear wheel's lateral traction. It would seem to me that the weight distribution (front-to-rear) will only match the tractive capability under a near zero acceleration.

 

The only reason I can see for possibly slight preference for acceleration (vs a slight deceleration) is that in marginal traction situations, a rear wheel lateral slide out is more easily tolerated by the operator than a front wheel slideout.

 

Why do you think it is BS? (see above)

 

Foot peg pressure? Let's ride two-up and you can have the footpegs (or whatever) - as long as I can have the handlebars.........!

Are you suggesting that it isn't possible to influence the bike by moving your weight around?

Not appreciably when compared to the powerful effects of handlebar inputs. If the handlebars are not touched, there is only a slight effect on the free yaw position of the front fork depending on the geometry etc of the fork setup.

[russell_bynum]

Are you suggesting that it isn't possible to influence the bike by moving your weight around?

 

Not appreciably when compared to the powerful effects of handlebar inputs. If the handlebars are not touched, there is only a slight effect on the free yaw position of the front fork depending on the geometry etc of the fork setup.

 

OK, absolutely. Bar inputs is the most efficient way to get the bike leaned. But footpeg pressure and body position can definitely play an important role. Would you agree with that, or is every professional motorcycle racer wrong?

 

 

As for being on the gas coming out of a turn...Every bike I've ever ridden (shaft drive, shaft drive with telelever, chain drive, belt drive, telelever front, conventional telescopic front, upside down telescopic front has felt more stable on the gas.

 

Every time I've had the front slide, it's from rolling into a corner without having the gas on enough...which puts too much weight on the front...and getting on the gas has fixed the slide every time.

 

Obviously, I'm talking about doing this in moderation, not just wacking the throttle wide open like a buffoon.

 

In addition to my personal experience, the MSF, Keith Code, David Hough, and basically every authority on riding technique says to accelerate through the turns, and they all seem to agree that it's the best thing to do...for the same reasons.

[ShovelStrokeEd]

I do it all the time, track, street, dirt, doesn't matter.

 

A couple of points.

 

As you roll into a turn, your tire radius decreases which, if you maintain engine RPM, will cause the bike to slow, you therefore need to apply some gas just to maintain speed.

 

Unless you a riding a bike from the 50's, the rear of the bike will not squat under acceleration, it will rise due to the relationship of the swingarm pivot to the axle (suspension geometry). Weight will transfer, in proportion to the rate of acceleration, rearward but the suspension will extend. Said extension will keep the rear shock in its best operating range and help to counter the effects of centripetal acceleration trying to compress the suspension.

 

I often apply a slight increase in throttle during, or even a little before, the turn-in and continue to modulate the throttle as the turn progresses. I'm by no means an expert rider but this technique, coupled with careful selection of entry speeds, allows me to get down the road in pretty good fashion with no complaints from the bike.

 

I have seen video of real experts while out there racing, video showing their right hands on the throttle and brakes. One, in particular, was a comparison of Rossi and Hayden at the same points on the track. Rossi was on the gas very much sooner than Nickie at almost every corner and surprisingly soon in the turn. Basically, as soon as the brakes were released and, in a couple of cases, before (I assume he was engaging in trail braking.)

[nrp]

Are you suggesting that it isn't possible to influence the bike by moving your weight around?

 

Not appreciably when compared to the powerful effects of handlebar inputs. If the handlebars are not touched, there is only a slight effect on the free yaw position of the front fork depending on the geometry etc of the fork setup.

 

OK, absolutely. Bar inputs is the most efficient way to get the bike leaned. But footpeg pressure and body position can definitely play an important role. Would you agree with that, or is every professional motorcycle racer wrong?

 

((((Read again here - I screwed up the format)))I contend that much of this is to improve the ground clearance in a severely banked situation. Forces contained within the bike structure stay there and do nothing, except they may give a rider confidence, or may allow him to torque or hold the handlebars differently. Forces within the footpegs-to seat otherwise don't do anything except maybe tie the rider to the bike with less compliance? Granted they allow the rider to laterally shift the net CG for handling or clearance reasons. It is also likely that wheel or suspension compliance becomes a more significant issue when heavily banked.

 

As for being on the gas coming out of a turn...Every bike I've ever ridden (shaft drive, shaft drive with telelever, chain drive, belt drive, telelever front, conventional telescopic front, upside down telescopic front has felt more stable on the gas.

 

Every time I've had the front slide, it's from rolling into a corner without having the gas on enough...which puts too much weight on the front...and getting on the gas has fixed the slide every time.

 

Obviously, I'm talking about doing this in moderation, not just wacking the throttle wide open like a buffoon.

 

In addition to my personal experience, the MSF, Keith Code, David Hough, and basically every authority on riding technique says to accelerate through the turns, and they all seem to agree that it's the best thing to do...for the same reasons.

 

I know they all say to do it. I even feel it slightly seems that way too, although I don't make any effort to accelerate in turns.

 

My problem as a mech engineer with a lot of 4 and 2 wheel vehicle dynamics experience, is why? I couldn't get a satisfactory answer in my BRC a few years ago. There was only a lot of arm waving and technical mumbo-jumbo that couldn't hold up under technical scrutiny.

 

I still don't think it needs to be talked about or tested significantly in a BRC. In the exam after taking the BRC I lost points for not accelerating during turns. This was after 35 years of riding experience. Humbling, I'll admit, but I still have the opinion. I looking for a technically rigorous answer.

[David]

[i looking for a technically rigorous answer.

 

Read Tony Foale's "Motorcycle Handling and Chassis Design: The Art and Science."

[ShovelStrokeEd]

Niel,

Not to pile on but this is said with a little smirk. A bunch of mechanical engineers, back in the 50's, proved to their own satisfaction that it was impossible for a wheel driven vehicle to exceed 1g of acceleration. Drag racers quickly put that to bed or top fuel cars would still be in the 8 second range. Heck, my drag bike, briefly, pulls better than 3g's for the first 60 feet. Of course, right now there is no motor in it so it can only do 1 g and then only if I throw it off a building.

[nrp]

Niel,

Not to pile on but this is said with a little smirk. A bunch of mechanical engineers, back in the 50's, proved to their own satisfaction that it was impossible for a wheel driven vehicle to exceed 1g of acceleration. Drag racers quickly put that to bed or top fuel cars would still be in the 8 second range. Heck, my drag bike, briefly, pulls better than 3g's for the first 60 feet. Of course, right now there is no motor in it so it can only do 1 g and then only if I throw it off a building.

Those MEs shouldn't have been able to prove the 1g limit. I remember hearing that sort of thing in my youth though.

 

The need for, or even value of acceleration in turns still escapes me - especially for new riders.

 

Feel free to beat on engineers though. We have some Civil Engineers here in Minneapolis that will have to generate some answers. I'm curious what they come up with on the I-35 bridge collapse. THX

nrpetersen

[beemerfan]

You've not addressed all the applicable forces in your discussion. In particular, you left out gravity, which is a bystander when a bike's traveling in a straight line, but becomes very much a player in a turn.

 

Most riding experts advocate constant speed or slight acceleration through turns - provided you're not at the handling limit. If you unwisely enter a turn hotter than rubber and road conditions will allow, then you're on your own and this discussion is over.

 

On the other hand, assuming you still have traction available (tire and road's ability to generate a counter force exceeds the intertial force of the turn), then slight acceleration ensures you stay ahead of the gravitational acceleration trying to make you fall over. Maintaining the exact right constant speed would do the same thing, but that exact right speed changes with turn radius and lean angle. So acceleration, to the extent you have remaining traction, reduces the number of variables you have to manage (along with giving many folks a more satisfying riding experience).

 

My $0.02 (maybe more like $0.015)

[vonbitski]

Hi nrp,

 

I'm, by no means, an expert in this discussion -- in fact, I'm only just getting into motorcycling...took my BRC course last month. But, I'm a scientist by training and my wife thinks I over-analyze everything, including biking, so I think I understand your need for some empirical data ;-).

 

The best source I've found for a description of the physics and such behind things like accelerating-through-a-turn come from David Hough's books: Proficient Motorcycling and More Proficient Motorcycling. I think the first book has more details on this subject, but I can't find it to save my life this morning. Here's what I pulled out of the second:

 

According to Hough, gently accelerating through a turns is good because:

 

1. it smooths out the wobbles at midturn

2. it keeps the bike up on the suspension and the weight better shared between the wheels

3. it helps conserve traction

 

In (1), he focuses on the notion that the wheel speed changes as the bike leans in the turn. Specifically, the greater the lean, the greater the circumference of the tire that is making contact (as you roll up the side of the tire). The wobble comes as the engine tries to synchronize with the wheel speed, and he says that rolling on the throttle while leaning keeps the engine pulling and the wheels turning at a more constant speed.

 

In (2), he points out that most bike suspensions will lift a bit under acceleration...even the rear end. That, in turn, gives the bike more lean-over clearance and gives the suspension a better chance to absorb bumps. His example: assume the bike has 6 inches of suspension travel, 2 inches of sag, leaving 4 inches of compression for bump asborption. In a 30 degree lean, 4 inches turns into 3.3 inches...at 45 degrees, you only have 2.8 inches. His point being that getting on the gas a bit will get you back some of that clearance.

 

 

He also points toward the transfer of weight to the rear by rolling on the throttle, thus giving the rear wheel increased traction. If I follow him correctly, since staying off the gas generates engine braking, which in turn eats up traction capacity on the rear wheel, decelerating into the turn reduces the amount of traction available.

 

His final argument is that the slow-look-lean-roll approach leads to smoother, more predictable lines, and as Martha Stewart would say, that's a "good thing."

 

Not sure if that's empirical enough to satisfy. The chapter in the book where we talks about this is interesting because he explains how he once felt exactly as you do -- he was unconvinced until he spent a bunch of time analyzing things himself.

 

Again, I say all this without being encumbered by knowledge or experience. Ask me to do a book report, though, and I'm all over it.

 

Cheers,

 

- David

[nrp]

According to Hough, gently accelerating through a turns is good because:

 

1. it smooths out the wobbles at midturn

2. it keeps the bike up on the suspension and the weight better shared between the wheels

3. it helps conserve traction

 

In (1), he focuses on the notion that the wheel speed changes as the bike leans in the turn. Specifically, the greater the lean, the greater the circumference of the tire that is making contact (as you roll up the side of the tire). The wobble comes as the engine tries to synchronize with the wheel speed, and he says that rolling on the throttle while leaning keeps the engine pulling and the wheels turning at a more constant speed.

 

In (2), he points out that most bike suspensions will lift a bit under acceleration...even the rear end. That, in turn, gives the bike more lean-over clearance and gives the suspension a better chance to absorb bumps. His example: assume the bike has 6 inches of suspension travel, 2 inches of sag, leaving 4 inches of compression for bump asborption. In a 30 degree lean, 4 inches turns into 3.3 inches...at 45 degrees, you only have 2.8 inches. His point being that getting on the gas a bit will get you back some of that clearance.

 

 

He also points toward the transfer of weight to the rear by rolling on the throttle, thus giving the rear wheel increased traction. If I follow him correctly, since staying off the gas generates engine braking, which in turn eats up traction capacity on the rear wheel, decelerating into the turn reduces the amount of traction available.

 

His final argument is that the slow-look-lean-roll approach leads to smoother, more predictable lines, and as Martha Stewart would say, that's a "good thing."

No I don't yet buy it. His statements are arm waving in my book.

 

1) The change in wheel rolling radius in a 30 degree bank (and that's a helluva big bank for any beginner) is only about 2%, which for a spark ignition engine (which operates as a constant torque device under most reasonable speeds and throttle positions) the reflected inertia requiring throttle change is essentially zero. Much more important is the chance of an accidental "goose" with the sensitive throttle on todays powerful bikes.

 

2) I accept the slight improvement in ground clearance in some bikes, but that is unimportant for beginner survival. His example M/C suspension numbers are not reasonable either.

 

3) the increased rear traction due to acceleration induced overturning moment comes only at the expense of front traction. It unbalances the lateral force abilities of the tire patches to react with maximum effect at the bike CG.

 

(Editing this) A possible insight from replying to this discussion though is that aerodynamic drag at higher speeds will causes a modest pitch up to the bike chassis. That can be compensated by slight acceleration to maintain the same proportions of lateral force capability in the tire patch to match the bike CG. The drag force is about 50 pounds at typical road speed, but rises as the square of the speed. This becomes a negative overturning moment on the bike chassis, which in marginal lateral traction situations can be rebalanced by slight acceleration. The necessary acceleration will also go as the square of the speed. Again though this is for a maximum performance situation as acceleration reduces the lateral force capability of the rear tire patch. I don't think it is for newbys. (Eureka!)

 

The Martha Stewart thing strikes me as more arm waving.

 

Q.E.D.(Latin) You math sorts will recognize what that means!

 

Thanks for the reference & comments though. Somebody has to know. My guess right now is the need for acceleration is from aerodynamic forces, but still should be of little use to newbys at reasonable speeds.

 

THX for the reply! I now see it!!!!.................

 

Niel