![]() |
01-23-2013, 08:25 PM
|
#271 |
|
Gnarly Adventurer
Joined: Dec 2003
Location: Pampa, Texas
Oddometer: 227
|
If you really want to test......
If you really want to test the idea that at very low speeds, the handlebar turns only in the direction of the turn, simply get a bicycle, add training wheels making positively sure they are adjusted so the bike itself is exactly perpendicular to the pavement, then remove the right training wheel. Mount the bike (it would have to be solid suspension) and ride. At ANY speed, try turning left.
You will immediately notice that without leaning, you will fall to the right. A single track vehicle HAS to lean. The ONLY way to induce the lean is with a countersteering motion caused by some part(s) of your body. If you are riding down a straight, level highway at 60 mph and ride without your hands on the bars, you can induce a countersteer with weight shift; HOWEVER, if you look at the steering head when you shift your weight, you will see the front assembly countersteer to start the turn.
__________________
"Though no one can go back and make a brand new start, anyone can start from now and make a brand new ending." -Carl Bard |
|
|
01-23-2013, 09:38 PM
|
#272 | |
|
Studly Adventurer
Joined: Mar 2012
Location: Central AL
Oddometer: 589
|
Quote:
|
|
|
|
01-24-2013, 07:57 AM
|
#273 | |
|
Studly Adventurer
Joined: Feb 2009
Location: Finland West coast
Oddometer: 962
|
Quote:
And don't ever go on another "riding" course !! I'm sure if there was a course for breathing, some people would take part... If you come out of a riding course, confused as heck... : The teachers SUUUUUUCK !!!!!! Unless there's Rossi as a teacher, do NOT attend !!!!!!!!!! Just ride. kyns screwed with this post 01-24-2013 at 08:09 AM Reason: i was confused |
|
|
|
01-24-2013, 12:18 PM
|
#274 |
|
ForwardAholic
Joined: Jul 2010
Location: North Central Idaho
Oddometer: 53
|
+1 , Yep you mention specifically in your post that you are not having any problems, just want to know if you need to CONCIOUSLY pay attention to countersteering, NO. Some of the best riders in the world have never given this a moments thought, they spend their time riding and worry more about what is, than why it is. For those that like to play around with things there is nothing wrong with practicing with a purpose but it doesnt do much good until it becomes automatic, and that takes tons of reps so if you want to get better at turning your bike, ride, ride, ride and practice safely quick darting turns until your body and brain learn how that feels to you, the underlying physics is real but does not need to be overthought to become a master of your machine.
|
|
|
01-25-2013, 03:16 PM
|
#275 | |
|
jack of all trades...
Joined: Dec 2007
Location: Delaware Ohio
Oddometer: 6,587
|
Quote:
Ah, pardon me... no it doesn't. If the rider leans in the bike can actually remain upright or even lean the other way. We did that all the time off road, to get the bike around a rock or log. The "lean" is the rider's weight to the inside. Besides, with your example you are setting up the exact same thing as a three wheeler and the way they turn is by using rider weight to the inside since they can not lean. If you didn't lean in the three wheeler would want to plow straight ahead. The reason so many new three wheeler riders would crash them while learning. Just sayin' it for the sake of argument...
__________________
Ever get lost? You know, that good kind of lost - come to a dirt road intersection and you have no idea where you are or which way to turn? I like when that happens! Mark - klx678 95 KLX650C w/Vulcan piston bigbore, 90 Zephyr 550 |
|
|
|
01-25-2013, 04:46 PM
|
#276 | ||
|
Adventurer
Joined: Jun 2010
Location: New England
Oddometer: 76
|
Quote:
We didn't' make this shit up. Have you looked on the web to see how physicists explain these phenomena / motorcycle dynamics? I can understand you not understanding the physics, hell it's complicated enough that I really have to work through the concepts to wrap my mind around them. But when multiple physicists (who are highly motivated to prove each other wrong), all come up with the same explanation, it might be time to relax and just accept the findings of greater minds - stand on the shoulders of giants, so to speak. I saw this quote the other day and it made me think of all y'all that can't be bothered with proven facts getting in the way of your version of the truth. Quote:
http://en.wikipedia.org/wiki/Bicycle...cycle_dynamics http://books.google.com/books?id=rJT...page&q&f=false Jedl screwed with this post 01-25-2013 at 05:03 PM |
||
|
|
01-25-2013, 06:03 PM
|
#277 | ||
|
I'd rather be riding
Joined: Oct 2005
Location: Oregon
Oddometer: 2,572
|
Quote:
Quote:
And it won't take more than practicing the concept on a couple of 20 mile rides on a road with medium to long radius curves for you to get it. It will quickly become second nature to you. And you will never look back. Applying countersteering consciously (although it will become natural quickly) is a very small step for a giant leap in riding skill. I guess I could write it better: it is a small push for a good and clean lean. Lion BR screwed with this post 01-25-2013 at 06:09 PM |
||
|
|
01-25-2013, 06:33 PM
|
#278 |
|
Adventurer
Joined: Nov 2011
Location: Hell Paso
Oddometer: 66
|
[quote=markk53;20524064
op, forget the science and ride.[/quote] +100! |
|
|
01-25-2013, 06:43 PM
|
#279 | |
|
Studly Adventurer
Joined: May 2007
Location: Barboursville, VA
Oddometer: 663
|
Quote:
Which is why I compare it to what you feel in a car. If you turn left, your weight shifts right and vise versa. When you turn the handlebars left on a motorcycle, the weight gets pushed right and the motorcycle leans right. Its as simple as that. Inertia is the strongest force that makes counter steering work but its not the only one. When you get a little deeper into the physics of it than explaining it gets complicated since the laws of inertia make things want to go straight and never turn left or right. This effect that gravity and inertia has on counter steering explains why its so easy to lean into a corner at low speeds but NOT be able to steer the bike back upright! Gravity helps a lot with getting a motorcycle leaned from being upright, however after the motorcycle is leaned over it now has to fight gravity to get upright again. If you don't have the speed (and inertia) for counter steering to take its full effect.... than gravity wins out. You can turn the handlebars further to create more corner G (thanks to inertia) but sooner or later you hit the handlebar locks. |
|
|
|
01-25-2013, 06:57 PM
|
#280 |
|
ForwardAholic
Joined: Jul 2010
Location: North Central Idaho
Oddometer: 53
|
The physics of turning a bike or motorcycle is the same whether a person is aware of the underlying physics or not, they are countersteering, if it is best for them to be conscious of this when they are a new rider how far do we take that, should little kids be given this course before the first bicycle ride, i suspect less than 1% of us knew about countersteering our first 2-wheel ride out, yet somehow we figured out how to countersteer very quickly. While it is never a bad idea to know more about any activity you are involved in there are plenty of accomplished riders from all schools of "feel" to promote overall practice as the most important thing to improving regardless of the current thought process going on in their head while they are doing it. Countersteering is only one of many critical issues going on during cycle riding and most newer riders have trouble multitasking at speed, once again there is nothing wrong with purposed practice (countersteering) for those that want to go that way, but there are at least millions of veteren riders that have done okay without being overly conscious of it.
|
|
|
01-25-2013, 08:30 PM
|
#281 | |
|
Studly Adventurer
Joined: May 2007
Location: Barboursville, VA
Oddometer: 663
|
Quote:
|
|
|
|
01-25-2013, 10:52 PM
|
#282 | ||
|
Adventurer
Joined: Jun 2010
Location: New England
Oddometer: 76
|
Quote:
Forgive me for kibitzing but I'm confused by your lack of enthusiasm for the classic "inverted pendulum" example, mostly because I offered the same example in another post. In an inverted pendulum, moving the base of the pendulum out from under the CoG accomplishes a lean two ways: 1) by allowing the offset support and gravity vectors to induce rotation around the base and 2) directly inducing rotation of the pendulum around it's CoG via acceleration of the base in a direction normal to the pendulum's length. For method #2, if we accelerated the base of the pendulum quickly and forcefully enough, the pendulum would "spin" around it's CoG (separating the base from the supporting hand) before gravity could bring the whole shebang tumbling to the ground. As we countersteer the front wheel's contact patch "pulls" the bottom of the front wheel sideways along a vector approx. normal to the bike's direction of travel and it's height. The movement of the contact patch is a response to lateral acceleration of that part of the tire that contacts the road surface just like the hand that supports the inverted pendulum. This acceleration then induces roll into the bike via the same two mechanism: 1) by allowing the offset support and gravity vectors to induce rotation around the contact patch and 2) directly inducing rotation of the bike around it's CoG. (OK, the second one is a bit of a stretch since the bike's CoG is not directly over the front contact patch) Are these forces not similar as for the inverted pendulum? I know there are other forces at work in the case of a spinning and turning motorcycle wheel, but are these two forces not similar for the most part? You are right that gravity is not the only force at work in this idealized inverted pendulum example or in the inducement of roll of a motorcycle. But the driving force (pardon the pun) is not inertia, but rather acceleration provided through the tires at a point some distance from the CoG, plus acceleration due to offset support and gravitational vectors, plus the torque induced by the changes in the angular momentum vector of the spinning wheel - all of which contribute to rotation around the bike's longitudinal axis. Forward movement is not required to induce roll in the "inverted pendulum". The device would react the same way moving at great speed or not moving at all as long as no additional forces were in effect. Forward movement is not required to induce roll in a motorcycle. All we have to do is stop supporting it and it will roll right over until it lays on it's side and hits the ground. Forward movement is required to control the lean of a motorcycle once the CoG becomes displaced relative to the line connecting the contact patches. Once the CoG is displaced laterally from the line of the contact patches, the only way to stop the rotation of the bike is to drive the contact patches to the other side of the CoG - where the rotational momentum of the bike will run squarely into the gravitation forces acting in the opposite direction. Forward movement is also required to counter external forces that would seek to roll the bike - like something impacting the bike from the side or a stiff gust of wind. The "seat of the pants" sensations of going around a turn in a car are not inertia "pushing" us outwards but rather acceleration from the tires through the suspension to the frame to the seat "pulling" on our asses into the turn. At any rate, that's how I understand the forces involved. But I'm eager to be educated, if I have things bass-ackwards. cheers, PS Inertia is not a force but rather a property of matter and physical objects. Inertia is what a force must overcome to induce translational or rotational acceleration on some object or thing. Jedl screwed with this post 01-25-2013 at 11:05 PM |
||
|
|
01-26-2013, 12:38 AM
|
#283 |
|
Adventurer
|
Countersteering is easely perceived if you ride with only one hand.
Go ride with only one hand - let's say your right one - and push the handlebar, see what happens. You won't be able to turn left pushing the right side. You will go right. Remember, use only one hand. Do the same riding with only your left hand. Push. You will turn left. Countersteering will be necessary only to initiate the turn or to increase the rate of turn. Once you have achieved the desired rate of turn, you will 'leave free' the handlebar and it will turn to the correct side you are turning, until you decide to change the rate of turning or end the turn. In short, what you do in a turn, known to you or not is: Initiate turn by countersteering. Reach desired rate of turn. Leave hadlebar free, it will reposition itself in accordance with the side and rate of turn. Countersteer in one or another direction as necessary to adjust rate of turn... leave handlebar 'free' when rate achieved. Finish turn by countersteering -now in the opposite direction of initial countersteer. All this, with all the fine tuning necessary, is done in the background by your brain sense of balance. But for increased safety in riding, it is very important to to be aware of the existence and necessity of countersteering. You can step in one of the footsteps and have a turn to that side, but the rate of turn will be very small compared with countersteering, and smaller as speed increases. RG
__________________
Rafael Guerra. '06 KLR650 Log: Miles: 13,600; MexTrek 09, and waiting for things to settle. With a KLR you can't can't have fun. RGuerra screwed with this post 01-26-2013 at 09:32 AM |
|
|
01-26-2013, 01:02 AM
|
#284 | |
|
plainsman
Joined: Nov 2005
Location: out in the great wide open
Oddometer: 89,147
|
Quote:
Yes.
__________________
_______ |
|
|
|
01-26-2013, 08:54 AM
|
#285 | |
|
Studly Adventurer
Joined: May 2007
Location: Barboursville, VA
Oddometer: 663
|
Quote:
The lean angle of a motorcycle (and rider combined) is the perfect equilibrium of gravity pulling it to the ground and cornering Gs keeping it up right. If you increase the cornering G by turning the front wheel into the corner, than the CG will get "pulled" in the other direction making the bike stand up right. So the CG needs to be forced UP and rotate which inertia can do in this case (from my understanding). There's no doubt its not the only thing going on too so maybe we're just debating the same thing. You are right that inertia isn't a force in itself. You most likely know more about physics than I do too and I'd be willing to learn anything. I've actually never taken a physics class in my life so there's no doubt many people know more about it than I do. I just learn through research and talking to others. |
|
|
|
![]() |
| Share |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|