down shift while turning....

[israel]

Why is my R1150R so solid down shifting as long as it aint leaned over??
I downshifted to accelerate mid turn, and my R just did not 'like' that.
Why do I not get the same ugly reaction decelerating or accelerating
mid turn??
IT does not make sense to me, what am I missing??
I can not even express my self clearly, I am puzzeled over this.
Hope someone 'gets' my question and states IT clearly preferably along with an answer.....
Israel

[NoRRmad]

This is not an answer to your question, but... It's a bad idea to downshift (or, to a lesser degree, upshift) during a turn. A sudden change in the torque coming to the rear wheel can break your tire loose, resulting in a skid.

But aside from that, in what way did your R "not like" that? Was it difficulty shifting, or did the bike lurch to one side or the other?

[-mcrides]

Why is my R1150R so solid down shifting as long as it aint leaned over??

The slightest jerkiness accelerating or decelerating will feel bad. It upsets the bike. When the bike is leaned over, the less input a rider gives, the better. This is standard teachings at track schools.

There was one track where I rode that had a tight sequence of turns. Mid way through the second, it just felt natural to me to downshift while leaned so as to come out of that corner in the proper gear to continue slowing for the upcoming hairpin. Downshifting once in the corner left me only one other downshift at exit instead of two.

My instructor (a Canadian Superbike racer) suggested that this was probably not good, even though my downshifts were seamless. I was building muscle memory. If I would later come to take those turns in the wet, My instinct would be to downshift mid corner. The slightest snatch, imperceptible in the dry, could be sufficient to break traction.

So I stopped.

Bruno
Montreal, Canada
http://pages.videotron.com/mcrides
:

[-mcrides]

Why do I not get the same ugly reaction decelerating or accelerating mid turn??

The bike doesn't like it. Corners should be negotiated smoothly, kind of like a sweeping motion.
a-decelerate, adjust speed for type of radius, select proper gear
b-turn in
c-at apex (roughly mid corner) begin throttling up smoothly
d-finish acceleration and upshift.

During b and c, it's critical to provide as little input as possible to the bike. This includes shifting gears, shifting weight around etc.

Everything has an effect. Notice how still racers are mid corner.

hope this helps,


Bruno
Montreal, Canada
Gerbing Heated JACKET LINER Review
http://pages.videotron.com/mcrides/prod ... /liner.htm
:

[Pat]

Hard to 'splain, but here goes:

The BMW's fuel injection system may or may not be unique, but the Bosch unit BMW was contracted to continue putting in their bikes is actually an older, less officiant design. It "reads" and adjusts the fuel/air maybe about two times a second, the newer units out there (and on the brand new Beemers) are now capable of reading and adjusting many MANY times per second.

That's part of the equation.

The other part of what's happening, is that your fuel delivery system is momentarily shut off..... not squirting any fuel, nada, when the throttle position sensor detects NO INPUT from your throttle.
Read, PRETTY SERIOUS (POSSIBLY ABRUPT) ENGINE BREAKING when you're not on the throttle........ as in letting off the throttle during a downshift.

So engine braking, 'compression', WITH A TRANSFER OF WEIGHT, ON A SMALLER REAR TIRE FOOTPRINT - WHILE LEANED OVER - IS GONNA MOMENTARILY/ALMOST LOCK UP YOUR REAR WHEEL!!!! Not a good idea to vary throttle input while leaning her over, ESPECIALLY with the engine braking these Boxers have, coupled with NO fuel flow to keep your engine spinning.

Now...... somebody else who knows what their talking about may be able to better explain what is happening, but that's the quick & dirty of it.

[mcrides]

So engine braking, 'compression', WITH A TRANSFER OF WEIGHT, ON A SMALLER REAR TIRE FOOTPRINT - WHILE LEANED OVER - IS GONNA MOMENTARILY/ALMOST LOCK UP YOUR REAR WHEEL!!!! Not a good idea to vary throttle input while leaning her over, ESPECIALLY with the engine braking these Boxers have, coupled with NO fuel flow to keep your engine spinning.

Very much so. Thottle jerkiness with a twin will have a greater effect than with a multi cylinder bike ie K bike.


Bruno
Montreal, Canada
http://pages.videotron.com/mcrides

[DJ Downunder]

It works fine for me...but you need to be very smooth letting out the clutch...it also helps to give the throttle a blip during the gear change.

DJ

[Boxerboy]

-mcrides had it right.
"The bike doesn't like it. Corners should be negotiated smoothly, kind of like a sweeping motion.
a-decelerate, adjust speed for type of radius, select proper gear
b-turn in
c-at apex (roughly mid corner) begin throttling up smoothly
d-finish acceleration and upshift. "

Smoothness and consistency is the key thru the corners for R series BMers. Gear changes, speed changes and braking can unsettle the bike and cause line changes that can and will put you on the wrong side of the road.
These bikes aren't built for racing like race bikes are. The engine configuration will do things to your handling if you're not adequately smooth. Negotiating a corner is about line and speed selection on the way in. If you get it wrong, wait 'til the corner is gone before trying too much correction. Then practice it until you get it right, otherwise you may not get another chance.

[collyers]

the solution to all this is a slipper clutch. Supermoto & MotoGP guys can go from 6th to 2nd, dump the clutch, and the slipper clutch will smoothly reconnect the transmission (simplified description). Otherwise, come into a turn in 6th gear, whip in the clutch, shift down to 2nd, dump the clutch...... and YOU get dumped. Methinks we'll see slipper clutches on sport bikes VERY soon, and then many other production bikes to follow. And, conversely, probably many "auto" (computer clutching) transmissions like the new FJ1300 optional tranny. Not my cup o' tea, but then I don't drink tea, either.
If you have to shift down mid-corner, be prepared to feather the clutch out to keep the chattering of the rear to minimum. Unless I'm riding WFO, I use engine braking to keep the bike stable once entry speed has been achieved, then roll on the exit speed (unless in supermoto riding mode, then it's "wheels OFF").

[mcrides]

the solution to all this is a slipper clutch. Supermoto & MotoGP guys can go from 6th to 2nd, dump the clutch, and the slipper clutch will smoothly reconnect the transmission (simplified description). Methinks we'll see slipper clutches on sport bikes VERY soon, and then many other production bikes to follow.

Slipper clucthes are great for track riding where tempo is much more intense. They're meant to give an extra edge to riders who are already skilled.

FWIW, I've never felt the need for a slipper clutch on the road. And none on a track either. Even when doing track days in the rain. All a slipper clutch would have allowed me is to be less careful with my downshifts. This could be an advantage if racing, but not at normal track day pace.

On the street, slipper cluthces will delay skill development. If you cannot downshift smoothly to begin with, all a slipper clutch will do is make sure you never learn. That's because you will never get the feedback that allows you to correct.

But the bigger liability is that it will encourage bad riding technique. For example, downshifting mid corner not as a result of strategy (ie choice) but as a result of weak technique. The slipper clutch will allow you to continue doing this and so never develop better riding technique.

Methinks we'll see slipper clutches on sport bikes VERY soon, and then many other production bikes to follow.

They have been on the GSX R1000 and ZX 10R for the last couple of years. I've ridden both.

I could see how they might benefit in the rain, but again, I've never felt the need for a slipper clutch in the rain. And I do a lot of rain riding.
So even if my bike had a slipper clutch, it would probably never kick in.


Bruno
Montreal, Canada
Gerbing Heated JACKET LINER Review
http://pages.videotron.com/mcrides/prod ... /liner.htm
:

[dallara]

Gee...

I guess in 35 years of riding, and 22 years of racing, I have been doing it *ALL* wrong...


Cuz' I downshift, upshift, make in-flight corrections to lean angle, corrections to body positioning, corrections to steering input, brake, and all sorts of other things mid-corner all the time...

Just ask Dean... Or Acacia... Or MooseR1100R... Etc....

Guess I better return all those trophies, plaques, and prize money checks ASAP, eh?

And this:

Not a good idea to vary throttle input while leaning her over, ESPECIALLY with the engine braking these Boxers have, coupled with NO fuel flow to keep your engine spinning.

Is especially a complete crock...

Dallara

[Gord]

I am hardly an expert rider. Only have 18,000 km experience under my belt. My MC course taught us to make all adjustments - throttle, gear, speed - prior to entering the lean. I have found that subtle variations in the throttle while in a turn need not be problematic if, as DJ says, they are done smoothly. I have shifted in a turn a couple of times but had the same experience as Israel. So I do all my shifting prior to entering the turn or as I exit the turn.

[mcrides]

Gee... I guess in 35 years of riding, and 22 years of racing, I have been doing it *ALL* wrong...

A skilled rider can make many things work. What I'd recommend to someone developing skills is different.

Cuz' I downshift, upshift, make in-flight corrections to lean angle, corrections to body positioning, corrections to steering input, brake, and all sorts of other things mid-corner all the time...

You do that because you're highly skilled.
As I mentioned, I downshifted mid corner leaned over without the slightest thought about it or effect on the bike.

Just ask Dean... Or Acacia... Or MooseR1100R... Etc....

Hey, I believe ya.

But I've yet to hear from track schools (and I've attended quite a few from 4-5 different brands) that moving around on the bike once leaned-in or making gross throttle changes is the hot ticket. Nor from the many books I've read.

In one of my schools, a couple of instructors were multiple past and present Canadian Superbike Champs and a few were top contenders. Same message.

Guess I better return all those trophies, plaques, and prize money checks ASAP, eh?

Ahh!! Keep-em.
But what I'd say to someone who finds that they need to correct gearing mid corner on a regular basis while riding on the street would be to review cornering technique. Ie you practice at getting the fundamentals right so you have a solid base.

To my mind that would come first, before suggesting to them how they can downshift more smoothly while leaned. Better to know how avoid the need in the first place and develop solid cornering technique based on good fundamentals.

Big twins have more input effect on bike handling mid corner ie while leaned than inline fours. Ie abrupt throttle on or off, non-smooth downshift etc. Something to be aware of.

Bruno
Montreal, Canada
http://pages.videotron.com/mcrides

[mcrides]

And this:

Not a good idea to vary throttle input while leaning her over, ESPECIALLY with the engine braking these Boxers have, coupled with NO fuel flow to keep your engine spinning.

Is especially a complete crock...

Do this in a ham fisted way in the rain, especially on a big twin, and you could find yourself on your gazzoo before you know what hit you!

This is one of those <Kids, don't try this at home > things.

Bruno
Montreal, Canada
http://pages.videotron.com/mcrides
:

[mcrides]

Why is my R1150R so solid down shifting as long as it aint leaned over??

The slightest jerkiness accelerating or decelerating will feel bad. It upsets the bike. When the bike is leaned over, the less input a rider gives, the better. This is standard teachings at track schools.

There was one track where I rode that had a tight sequence of turns. Mid way through the second, it just felt natural to me to downshift while leaned so as to come out of that corner in the proper gear to continue slowing for the upcoming hairpin. Downshifting once in the corner left me only one other downshift at exit instead of two.

My instructor (a Canadian Superbike racer) suggested that this was probably not good, even though my downshifts were seamless. I was building muscle memory. If I would later come to take those turns in the wet, My instinct would be to downshift mid corner. The slightest snatch, imperceptible in the dry, could be sufficient to break traction.

So I stopped.

Bruno
Montreal, Canada
http://pages.videotron.com/mcrides
:

[mcrides]

Why do I not get the same ugly reaction decelerating or accelerating mid turn??

The bike doesn't like it. Corners should be negotiated smoothly, kind of like a sweeping motion.
a-decelerate, adjust speed for type of radius, select proper gear
b-turn in
c-at apex (roughly mid corner) begin throttling up smoothly
d-finish acceleration and upshift.

During b and c, it's critical to provide as little input as possible to the bike. This includes shifting gears, shifting weight around etc.

Everything has an effect. Notice how still racers are mid corner.

hope this helps,


Bruno
Montreal, Canada
Gerbing Heated JACKET LINER Review
http://pages.videotron.com/mcrides/prod ... /liner.htm
:

[mcrides]

deleted double post

[Bones]

Did I see a reference to "smaller footprint while leaned over.....", because that is just plain, outright INCORRECT.

On any of the modern tires that the 1150R will be wearing, the footprint (contact patch) will be SMALLEST with the bike exactly upright. It will increase in size a bit as the bike is leaned, and stay that way until such time that lean angle brings the very edge of the tire to the road....any further, then contact patch will shrink. HOWEVER, this does not mean that TRACTION is greater with the bike leaned, just because the contact patch is larger, as there is a relationship between lean angle and traction that has, in part, to do with vectors of rotation between the surfaces (linear with the bike upright and rotational with the bike leaned) among other things.

I felt compelled to post this, only because the information given was plain and simple, incorrect. Certainly, I think we agree that incorrect information should not be propagated.

Re whether or not you modulate the throttle or shift with the bike leaning is certainly a matter of personal decision....but I am not sure how you ride with any skill whatsoever if you never do any midturn adjustment to the multitude of controls you have at your disposal (throttle, clutch, front brake, rear brake, handle bars, body position).

Bones

[mcrides]

Did I see a reference to "smaller footprint while leaned over.....", because that is just plain, outright INCORRECT.

Well. . .we want to avoid getting hung up on a term and missing the concept.

Your tires' grip varies on a continuum. At one end, you have maximum cornering grip. At the other hand you have maximum grip for accelerating or braking. As you dip into one, you lose the other. So the more leaned you are and the more grip your tires are generating to keep the lean, the less you have available for braking or accelerating. That's what happens when you brake mid corner and low side.

What this means is that gross, not modulated inputs can have a negative effect on the bike. And a twin can provide more gross input than a multi. That's just the way it is. I didn't invent that.

Re whether or not you modulate the throttle or shift with the bike leaning is certainly a matter of personal decision....but I am not sure how you ride with any skill whatsoever if you never do any midturn adjustment to the multitude of controls you have at your disposal (throttle, clutch, front brake, rear brake, handle bars, body position).

It's always easy for meaning in a thread to get lost or wander. You can do anything you want while leaned in a corner, as long as you are in control and are the one choosing the action and are happy with the results.

I understood this topic as coming from a rider who was getting unwanted results.

Incidentally, this is why conventional wisdom is that when someone wants to learn how to ride or drive, they should take lessons from a certified school. The worst is learning from someone who says they can teach you because they've been doing it for 20 yrs. If someone I know wants to learn to ride, I refer them to a school. That way, I don't transmit any of my bad habits.



Bruno
Montreal, Canada
http://pages.videotron.com/mcrides

[darthrider]

Bones said:

Code: Select all

...but I am not sure how you ride with any skill whatsoever if you never do any midturn adjustment to the multitude of controls you have at your disposal... 

This is a great lead in to "another thing".

When thinking of training, specially the "self-training" (and practice) that we should all do, sometimes the only way to really learn something 'right' is to experience what if feels like 'wrong'. This would include such things as intentionally, momentarily locking the front brake and locking/skidding the rear brake & tire - upright, straight-lines please! This is the only way to learn where that lock-up point is and will help you learn to brake right up to the edge of lock-up where *maximum* braking occurs. It can make the difference in stopping 1 foot before you hit the SUV that pulled out in front of you, or 1 foot "into" the door of that SUV.
I DON'T want to start another ABS war so I'll just say this about a bike with ABS brakes than can not be disabled...you can still learn from this exercise, just not as much. You'll have to practice learning where the ABS activation point is. This is still very important as in the SUV example above, you may stop 6" before you hit the SUV by maximizing your brake usage, or 1" into the door with full-zoot ABS engagement from the first application of the brakes.
These numbers are made up, of course but do provide a real-world illustration of where a non-ABS bike might be *slightly* better in the hands of a practiced, skilled rider vs. one who never practiced brake control and just relied on "grabbing a big handful" of ABS for emergencies.

No matter what you ride or what type of brakes you have...PRACTICE BRAKING! And not just once but often. What I'm trying to get to is the importance of practice, no matter what kind of brakes you have or what your experience level...we just all must practice *if* we want to maximize our odds. I think everyone agrees with that. Think of that pilot in the left seat the next time you fly, and how important you think it is for him to be well practiced.

Taking control actions in corners, like ABS itself, is debateable...as a general practice. But a very good idea for say, an intermediate level rider to learn more about cornering, being smooth, his motorcycle's capabilities and his own abilities.

Here's another real world example...through the years on the street and in racing I've tried everything I can think of to try in corners...to be faster or smoother or safer or just out of curiosity. It doesn't bother me for the bike to wiggle, for a front or rear tire to slip or for both tires to drift, or even slide a bit because I've "been there, done that". It's familiar territory and I've practiced causing it, avoiding it, 'living' with it and even playing with it for fun. When it happens by surprise, you do what you train to do so it's (usually!) no biggy.
OK, here's the real world part:
My new Speed Triple is a wonderful mount for an intermediate thru expert level rider to enjoy and be very safe on. A novice would be lucky not to get hurt if he was trying to use more than maybe 50% of the bike's capability. I'm very experienced and consider myself an expert rider and I'll be lucky if I ever learn to use 90% of this bike's capabilities. But I push it a little more and a little more until I pretty well know what it's going to do...and how capable I am in "leading the bike" rather that just reacting to it.
The fuel injection system is excellent. Except for one thing: The first "nth degree" of throttle is like a light switch...On or Off. No biggie just going down the road.
But in a corner, leaned over to the edge of the tires, throttle off until just before or at the apex, when you try to gently, smoothly, r-o-l-l the throttle on it comes on very abruptly. Very disconcerting at first, still is a little. At best it makes the bike waggle a bit, briefly. At worst it will break traction at the rear just for a second.
Niether of those things are a big deal. But could be if I over-reacted, reacted improperly. Or, if I hadn't been practicing this, I might not even know about it and just give that throttle a big old whack and maybe hit the ditch.

Point is, practice that downshift in corners, practice doing corners right *and wrong* until the differences are not startling and you are not surprising yourself. More throttle, less throttle, quicker throttle, countersteering, lower body steering, you get the idea.
I'm not saying spend all your time practicing doing things wrong, just enough so you understand them and can avoid them.
Practice those brakes...in corners too. Unfortunately, not all emergencies happen when we are straight & level.
Don't know how to brake hard in a corner or fast curve? Go take the MSF Experienced Rider course and they will show you. Then go practice it. Last time I took it, that little technique kept me from hitting an Armco barrier at about 65 MPH and probably going over the edge and down to the rocks below.
I had been practicing.