GENERAL > BIKE TALK

THE BASICS:

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JHerheim:
How does MSF teach braking wrong?   And what would be the right way based on the target audience and intended outcomes of the basic rider class? 

Is it taught properly in the ARC?  advanced rider class?


How come Metzler and Bridgestone  both state to use the recommended tire pressure in your motorcycle owner's manual as a starting point?   Of course they are assuming you use the recommended tire for your application. -



But beyond my bickering.   Kirk does have great points, and good advice.  :thumb:

Kirk:
You sound like someone who has served as an MSF RiderCoach.  If so, thank you for your service.  You guys do a better job than anyone, at introducing new people to our sport.

And don't worry, you're not bickering.  Bickering is arguing about trivial matters. Motorcycling on public roads is done by "Big Boy" rules- If you get it wrong, you stand the very real chance of going home in a box.  Life and death matters are not trivial, and we are not arguing- I made a statement, and you asked me a question, which I will now answer.

The MSF is apparently still teaching students the divided attention task of attempting to use both brakes.  I suspect it is because the course was probably developed back when motorcycles had crappy drum brakes, tube-type bias-ply tires, and crude spring-on-a-stick suspension.

The following is from a braking tutorial posted in the TECH section:


--- Quote from: Kirk on June 19, 2006, 08:56:03 PM ---We have members here of all different skill levels. I'd like for all of them to survive. To that end, I'd like to initiate discussion on the rear brake. I am not the fastest, nor am I the smartest. But I'd like to share what I can with those that I can help. At the risk of presenting this in an overly basic manner, I'd like to make sure that we include everyone in the ability to live longer.

Point 1:

If you hold up a stationary motorcycle up and then let go of it, it will fall over. It falls over because there's nothing holding it up.

If you ride the same motorcycle down the road at 60 mph and let go of the handlebars, it doesn't fall over. It doesn't fall over because of the gyroscopic force of the rear wheel spinning.

Point 2:

The limit of braking on road-going 4-wheel vehicles is usually the limit of traction of the tires. The harder you brake, the closer you get to the limit. At the limit, the tires start to skid. At that point, you can't brake any harder or the tires will lock up and slide. Braking with more wheels (front and rear) is the only option to maximize braking force.

Motorcycles are different. 400 pound sporting motorcycles come with brakes the size that come on a 3500 pound Corvette. The brakes are not going to limit braking force. Sport motorcycles also come with tires capable of providing pavement grip similar to the grip that bikini wax has on...well, you get the point. Heck, a lot of us do stoppies in the rain. So tires aren't going to limit braking force either. That pretty much leaves weight transfer, which is the real limit of braking.

A sporting motorcycle going down the road at a steady speed has about 50% of the weight on the front tire, and about 50% of the weight on the rear. As you brake, the weight balance shifts towards the front, proportional to the amount of braking force applied. As you brake harder and harder, more and more weight is shifted to the front tire. As you approach 100% of the weight on the front tire, the rear tire obviously is approaching 0%. Just as obvious is that applying the rear brake with 0% of the weight on the rear tire is going to do absolutely nothing to slow you down. What it will do, is lock the rear tire up. I refer you to Point 1 above to find out what happens to the motorcycle when the rear wheel isn't turning.

It gets worse if you aren't going in a straight line. If you lock up the rear wheel and low-side the bike in a straight line, that's bad enough. But a tire only has x amount of traction available. If you're already using 60% of it's available traction for cornering, and you use the rear brake pedal to demand another 60% for braking forces because you think you went into a corner too hot and had an anxiety attack, the rear tire is going to lock up. The instant the rear end steps out, your brain will have one of those "Oh shoot" moments, causing you to instinctively release the ejector lever...err...rear brake lever. The rear wheel is now free to instantly regain full traction, with the bike still sideways and banked over. The bike will snap bolt upright, and since it weighs about twice what you do, it's going to catapault you up into the air, accelerate you to roughly twice the speed that you were going right before you became a flesh projectile, and in the most literal manner, your bike will follow you in the same way that the ACME anvil follows Wile E. Coyote off a cliff. It's bad enough to get thrown like a lawn dart into a rock wall, but to have a 500 pound motorcycle use you for a tent peg right afterwards is adding insult to injury.
--- End quote ---

And thank you again for your service.  :tu:

JHerheim:
No argument like that.   But you didn't answer how it should be taught.    You are giving pretty decent advice, but a person who that really should be targeted for should have more knowledge than what is offered in a MSF basic rider course.


Brakes are in the hands of the end user.   Both brakes on a race track are a highly advanced skill set that few will ever try and develop and fewer will actually be good at. 

MSF does clarify in it's teaching that both brakes are only as effective as their traction.  As you've said   As weight shifts the rear brake is certainly less effective, and becomes to the point of useless.   But this is also controlled by the rider.     The rider can control how fast it shifts by application, and their weight on the motorcycle.    They even deal with how to handle a rear wheel skid.   But assume it starts while trying to brake in a straight line.

Both brakes will a stop better than one brake while traction is available 100% of the time.    But you are correct that at a higher stress level and speed you are multi-tasking when you are trying to save yourself.    People are going to do as they have trained, and if they haven't trained for this high stress emergency braking situation on their bike in those conditions, disaster may happen.    But to say the rear brake is worthless is not correct in all cases, different bikes stop differently.   You can't stop a police issue road king at the best of it's ability without using both brakes.  And please forget the "real bike" argument here.   


One of the take-aways from any MSF program should be  "boy, do I have a lot to learn, or a huge window for improvement"   I assume that should be the same at any level of skill training. 

Challenge with the MSF Basic Rider Course  in my opinion is that it does not give the instructor the latitude of acknowledging a persons ability and skill level as they walk in the door.  All people are given the same instructions and expectations to develop the same entry level skills, as if they have never seen a motorcycle before.    In fact if you go, you will not learn to ride a motorcycle.  You will have the opportunity to gain some confidence with the motorcycle controls and operation on a very basic level.   If you miss the part at the end where you are encouraged to find higher level skills courses, and the need to redo many of these basic exercises and really learn to bond with your own motorcycle.   You may leave with the believe that MSF thinks , "this is the way all people should ride and there is no other way"

I wish that wasn't the norm.   But for many of the MSF non believers- they just don't understand what the class is really about.

Now the ARC on the other hand does allow for riders of many skill levels.   But still does focus on street riding.   I tell people that at the end of the class you can choose to use your new beginner super powers for good or evil.    I try to teach body position in cornering.  Threshold braking,  trail braking, braking while leaned over, amongst some standard idea's of road safety.    And it's a bring your own bike course.  I get to deal with any two wheeler that could have a license plate in Wisconsin, even things that most would call a scooter.        At the end,  I try to steer those who like what they did and would like to try a faster version into a local track day or track school..      for the most part All school is good school..


I enjoy helping people learn how to play and have fun,  while helping them learn accurate self evaluation.   I think I like working the entry level track day clinics the best though,  little faster, a little more fun, and I pick up way more myself in that atmosphere.       


     

Kirk:

--- Quote from: JHerheim on December 03, 2011, 12:52:53 PM ---No argument like that.   But you didn't answer how it should be taught.    You are giving pretty decent advice, but a person who that really should be targeted for should have more knowledge than what is offered in a MSF basic rider course.
--- End quote ---

Correct braking should be taught on the race track.  I thought I already said that, but I'm getting a little forgetful in my advanced age. 

Many of your students have become my students, including my wife.


--- Quote ---Both brakes on a race track are a highly advanced skill set that few will ever try and develop and fewer will actually be good at.
--- End quote ---

This is true, but it's even more true on the street.  Racers do brake hard, but racers tend to leave a margin, and their job is simpler, because every braking zone is the same as it was the last time they saw it, a minute and fouteen seconds ago, and everyone around them is competent.  On the street, if you're doing 45 mph down a 5-lane thoroughfare and a soccer mom pulls out in front of you leaving no other avenue of escape, you are now faced with a maximum braking situation.  Energy increases with the square of velocity, and the human body can only survive so much energy.  You need to dump as much energy, as fast as possible, with the ultimate goal of avoiding that cold stainless steel table.   


--- Quote ---As you've said   As weight shifts the rear brake is certainly less effective, and becomes to the point of useless.   But this is also controlled by the rider.     The rider can control how fast it shifts by application, and their weight on the motorcycle.
--- End quote ---

Under maximum braking, the RATE of weight transfer should be as quick as possible.  You need as much weight on the front tire as possible, to anchor it into the pavement.  SNAPPING the front brake on is counter-productive, as the force of your brake application may surpass the traction available from an under-weighted front tire.  But if you are implying that intentionally transferring weight at a slower rate somehow reduces stopping distances, I gotta call BS.  Whatever RATE you transfer weight at, you are eventually going to arrive at 100% front and 0% rear- if this is MAX braking we're talking about, how many feet are you gonna roll with the brakes partially applied, before you have enough weight on the front tire to get serious about braking?   


--- Quote ---Both brakes will a stop better than one brake while traction is available 100% of the time.
--- End quote ---

No they won't.  In fact, the exact opposite is true.  When riding in snow, where virtually no weight transfer is possible, both brakes will stop you faster because you are taking advantage of what little traction is available, from both tires.  Under any normal riding, the rear brake has no role.  I can lift the rear tire in a driving rain storm.  Anybody who stops faster with both brakes, wasn't really stopping fast to start with.  What they THOUGHT was 70% front and 30% rear, was more likely 40% front and 10% rear, leaving 50% of their braking power un-used.  Most people have no freekin' clue how hard a competent modern motorcycle can stop.  My biggest concern in a max-braking situation on the street isn't the cage in front of me- it's the one with all four tires chirping in a full ABS stop behind me- I don't want to get ass-packed because the housewife behind me can't stop as fast as I can.


--- Quote ---But you are correct that at a higher stress level and speed you are multi-tasking when you are trying to save yourself.    People are going to do as they have trained, and if they haven't trained for this high stress emergency braking situation on their bike in those conditions, disaster may happen.
--- End quote ---

How you train is how you'll fight.  Under stress, we don't rise to the occassion- we fall to our level of training.  Fine motor skills go right out the window in stressful situations, and throwing a pointless and dangerous divided-attention task into their lap when it happens, can be fatal.


--- Quote ---But to say the rear brake is worthless is not correct in all cases, different bikes stop differently.   You can't stop a police issue road king at the best of it's ability without using both brakes.  And please forget the "real bike" argument here.
--- End quote ---

Harley jokes aside, a Road King is NOT a competent motorcycle. A police-issue Connie 14 is a competent motorcycle.

I am not able to give advice on surviving incompetent motorcycles- it's simply outside my depth of expertise.

Rather than bringing a rubber-mounted Heretige-Edition chrome-plated Dreamin' Beagle pocket-knife with optional skull appliques and Genuine Knife Company (tm) logo-emblazened pleather tassles with fold-out rape whistle, to a gun fight, I think one should bring a gun.  A good one. 


--- Quote ---Challenge with the MSF Basic Rider Course...  In fact if you go, you will not learn to ride a motorcycle. 

You will have the opportunity to gain some confidence with the motorcycle controls and operation on a very basic level.
--- End quote ---

True.   


--- Quote ---I enjoy helping people learn how to play and have fun,  while helping them learn accurate self evaluation.   I think I like working the entry level track day clinics the best though,  little faster, a little more fun, and I pick up way more myself in that atmosphere.
--- End quote ---

Thank you again for your service.

biggar:
Good stuff Kirk.  Even brought me out of the woodwork to log in here.



Gar

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