January 7th, 2017, 01:57 PM | #1 |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
"Good and bad" friction in motorcycling: mention some
Copied from
https://en.m.wikipedia.org/wiki/Friction "Friction is a force that opposes or resists the relative motion of solid surfaces, fluid layers, and material elements sliding against each other." That force is silently but relentlessly present in riding, as well as inside and outside our machines. The "good" friction is beneficial: what do we do to get more of it? What do we do to reduce the "bad" friction? Mention some of the bad and good ways in which friction works in a motorcycle: there are many; possibly more than what some members imagine.
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
January 7th, 2017, 06:11 PM | #2 |
ninjette.org guru
Name: john
Location: placerville
Join Date: Apr 2016 Motorcycle(s): ninja 300 Posts: 386
|
clutch plates
|
1 out of 1 members found this post helpful. |
January 7th, 2017, 06:21 PM | #3 |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Good friction: tires on pavement, tires on rim, nuts and bolts staying tight (sometimes aided by Loctite, lock washers, etc), butt on seat, gloves on handlebar, boots on pegs, clutch plates on each other, brake pads on disks, bearing races pressed in their bores
Bad friction: just about everywhere else, lubricants, balls, rollers used to decrease it |
1 out of 1 members found this post helpful. |
January 7th, 2017, 11:18 PM | #4 | ||
ninjette.org certified postwhore
Name: TC
Location: Hawaii
Join Date: Sep 2013 Motorcycle(s): A lot. Posts: A lot.
|
Jim nailed it. Couldn't have said it better myself.
Quote:
Quote:
__________________________________________________
Just batshit crazy. All his posts are endless diatribes. Some are actually entertaining but mostly batshit crazy. |
||
1 out of 1 members found this post helpful. |
January 8th, 2017, 07:53 AM | #6 |
Cat herder
Name: Gort
Location: A secret lair which, being secret, has an undisclosed location
Join Date: May 2009 Motorcycle(s): Aprilia RS660 Posts: A lot.
Blog Entries: 6
MOTM - Jul '18, Nov '16, Aug '14, May '13
|
Good: Money to track day provider
Bad: Money to wallet
__________________________________________________
I am NOT an adrenaline junkie, I'm a skill junkie. - csmith12 Nam et ipsa scientia potestas est. Heri historia. Cras mysterium. Hodie donum est. Carpe diem. |
|
January 8th, 2017, 05:48 PM | #7 |
ninjette.org certified postwhore
Name: Tom
Location: Northern Virginia
Join Date: Jul 2015 Motorcycle(s): 2001 Ninja 250, 2019 Harley Ultra Classic, 2001 Suzuki SV650 Posts: A lot.
MOTM - Jan '16
|
Bad Friction: My skin sliding across pavement.
|
|
January 8th, 2017, 06:26 PM | #8 |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Good one, Tom! I've always noticed that falling onto an ice rink while going 30 mph is painless, compared to a similar fall onto dry pavement at the same speed.
|
|
January 8th, 2017, 06:42 PM | #9 |
ninjette.org certified postwhore
Name: Eric
Location: Iowa City
Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot.
Blog Entries: 54
MOTM - Sep '18, Feb '16
|
For me the worst friction is air friction on bodywork. Then bearing friction as drag and tire friction. To counter the bad I reduce frontal area and remove bumps that disturb airflow. For bearings I use world wide bearings. ( shameless plug for sponsor). And for tires I have minimal tread and over pressure.
Good friction is clutch disc friction. Piston ring sealing and bolts staying tight.
__________________________________________________
Top speed 123.369mph. Ohio mile Worlds fastest 250 ninja |
1 out of 1 members found this post helpful. |
January 8th, 2017, 06:56 PM | #10 |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
I'd bet that most of the losses from air are from pressure, rather than friction. That is high pressure forming in front of, and low pressure forming behind parts of the motorcycle and you.
|
|
January 8th, 2017, 07:19 PM | #11 |
The Corner Whisperer
Name: Chris (aka Reactor)
Location: Northern KY
Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much.
MOTY 2015, MOTM - Nov '12, Nov '13
|
Just a few
Too much "friction" on grips and pegs do not allow riders to move "effortlessly." Be careful what you clean your seat(s) with, you don't want it too slick. Watch your fork seals, if they leak on your rotors and then you ride, sure... it will burn off after the first couple of times hitting the brakes but it's destroying your pads. Learn to lube your cables, friction is not good here.
__________________________________________________
Goal: Shake A Million Hands | Look through the corners | Track Day Prep | Closest track? | The Mid-Ohio School |
1 out of 1 members found this post helpful. |
January 8th, 2017, 08:21 PM | #12 |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Man, that's true! I once rode in a boat that had its seats coated with Armor All. Then I drove my Dodge van home. A few days later, with the van door open, I made a little running leap into the driver's seat, slid across the seat and onto the the floor behind the engine cover. I can't imagine what would happen if you used that stuff on a motorcycle seat.
|
|
January 8th, 2017, 08:22 PM | #13 |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
All excellent posts above !!!
More bad friction examples: 1) Dirty pistons sliding back into the calipers when brake lever is released. 2) Increased stiction of the telescopic tubes and guides of front suspension during hard braking. 3) Power consumed by the pump to force coolant through the pipes, thermostat and radiator. 4) 212 X or O-rings rubbing against the steel plates of a poorly lubricated chain. 5) Intake air and exhaust gases flowing through air filter, throttles, manifolds and exhaust pipes (it is called pumping loses and pistons are the ones doing that work / It involves changes of pressure and volumes of air and gases also, not only friction; just like the aerodynamic loses).
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
January 8th, 2017, 10:03 PM | #14 |
ninjette.org certified postwhore
Name: TC
Location: Hawaii
Join Date: Sep 2013 Motorcycle(s): A lot. Posts: A lot.
|
Congrats on member of the year motofool. I voted for you.
All of your threads are very informative and I enjoy reading them.
__________________________________________________
Just batshit crazy. All his posts are endless diatribes. Some are actually entertaining but mostly batshit crazy. |
|
January 9th, 2017, 07:07 AM | #15 | |
ninjette.org certified postwhore
Name: Eric
Location: Iowa City
Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot.
Blog Entries: 54
MOTM - Sep '18, Feb '16
|
Quote:
http://www.engineering.com/DesignSof...You-Drive.aspx Air presssure is air friction. Also sound is friction. Or rather there is no sound without friction.
__________________________________________________
Top speed 123.369mph. Ohio mile Worlds fastest 250 ninja |
|
1 out of 1 members found this post helpful. |
January 9th, 2017, 08:55 AM | #16 | |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Quote:
Air pressure waves acting on an ear drum move it because of the pressure changes at the drum's surface. The air is not actually grasping the ear drum using friction. |
|
|
January 9th, 2017, 09:10 AM | #17 |
ninjette.org certified postwhore
Name: Al
Location: York, Pa
Join Date: Dec 2012 Motorcycle(s): 2013 Ninja 300..............2008 Ninja 500-sold...2009 Ninja 250-Crashed Posts: Too much.
MOTM - Sep '14
|
Pressure itself is not friction but air moving from high pressure to low would have friction. High-pressure pushing and low-pressure pulling I would not think is friction anymore then it is friction that causes your piston to move when gas is ignited in an internal combustion engine.
__________________________________________________
Keep calm and ride on -Motofool Never quit on a rainy day -ally99 |
|
January 9th, 2017, 11:16 AM | #18 |
ninjette.org certified postwhore
Name: Eric
Location: Iowa City
Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot.
Blog Entries: 54
MOTM - Sep '18, Feb '16
|
I believe that to get the air moving there must be a friction of some sort. Strumming of a guitar string or fingernails on a chalk board produce friction that begin the sound waves moving.
I think the turbulence on the sides are a result of air friction on the surface . I could be wrong on both counts but that is what learning is al about. Exelent discussion.
__________________________________________________
Top speed 123.369mph. Ohio mile Worlds fastest 250 ninja |
|
January 9th, 2017, 12:28 PM | #19 |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Air generally gets moving because of pressure differences. As an example, when you blow air out of your mouth, you use your diaphragm to squeeze your lungs and raise the pressure of the air in them a little, and it flows to a region of lower pressure in the room.
You're right that it's possible to get air moving by friction. If you move a piece of cardboard through the air, with it oriented for least resistance (aligned with the movement), some air will be dragged along with it by friction. But if you turn it sideways so it's oriented like a paddle, it will create a high pressure region in front of it and a low pressure region behind it, both tending to get air flowing in its direction of movement, and it will move a lot more air. |
1 out of 1 members found this post helpful. |
January 9th, 2017, 04:09 PM | #20 |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Yes, air loves sticking to solid surfaces.
Then the next layer of air molecules cannot stick that well and it slides a little over that one (relative movement and friction or viscosity effect happens between those two). The next layer away from the solid surface resists the movement or disturbance due to inertia and also slides over the layer described above, and so on, until the molecules of air that are very far from the solid surface remain non-disturbed by the relative movement of the solid. In order for a solid in movement to create a difference of static pressure, it must change the direction of the molecules, which is acceleration, which consumes energy. It is all Coanda's fault: http://www.formula1-dictionary.net/coanda_effect.html https://en.m.wikipedia.org/wiki/Coandă_effect
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
1 out of 1 members found this post helpful. |
January 11th, 2017, 10:12 PM | #21 |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Thank you very much
Some more examples of good friction: 1) The friction between swingarm and bearings assembly, which prevents the rear wheel from sliding back and forth due to breaking and the pull of the chain, keeping the proper alignment. That friction is proportional to the torque applied onto the axle-nut. 2) The friction between the handle of the cockpit and the exterior washer and internal neoprene disc, which keeps it in the position that we have selected. 3) The interference or press fit between the outer ring of the bearings and the aluminum casing of the wheels, crankcase, etc. https://en.wikipedia.org/wiki/Interference_fit 4) Blade type male-female electrical connectors.
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
January 11th, 2017, 11:22 PM | #22 |
ninjette.org certified postwhore
Name: TC
Location: Hawaii
Join Date: Sep 2013 Motorcycle(s): A lot. Posts: A lot.
|
Wow this thread is getting pretty technical. I consider myself to be some form of engineer but regardless of job description and technical terms used to describe the thing being discussed, it's really all more the same than different. Knowledge is power, and all information is ultimately transferable from one circumstance to the next.
I think the simple term is "common sense" but these days it doesn't seem so common. It's wonderful that we have reached a point in human history where we have the technology to freely communicate complex thoughts to people who are hundreds or thousands of miles away. Sound, pressure, and friction are all variables. I think that a very relative variable to consider is atmospheric density. We can all agree that a motorcycle runs quite differently depending on the weather condition.
__________________________________________________
Just batshit crazy. All his posts are endless diatribes. Some are actually entertaining but mostly batshit crazy. |
1 out of 1 members found this post helpful. |
January 12th, 2017, 10:26 AM | #23 |
Old and slow
Name: Lohman
Location: Aiken, S.C.
Join Date: May 2014 Motorcycle(s): Suzuki TL1000R, Honda CBR600F3, Ninja 250 Posts: 889
|
thread winner right there.
__________________________________________________
|
|
January 12th, 2017, 10:56 AM | #24 | |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Quote:
Hot-humid weather not only reduces the performance of engines, but increases viscosity of the air (behavior that is opposite to the one for liquids, like oil). http://www.engineeringtoolbox.com/ai...ity-d_601.html Higher viscosity of the air means that it is a little harder for it to go through the air filter and intake passages. The part of aerodynamic drag that depends on friction among layers of still air and the surfaces of the bike and rider, is also a little higher in hot weather. Some compensation to the above comes from the fact of lower number of molecules (less density) have to be disturbed and pushed around by the bike while going through at high speeds. Notice that is the density of air in this equation of drag force. https://en.wikipedia.org/wiki/Drag_coefficient
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
|
January 12th, 2017, 04:22 PM | #25 | |
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Quote:
https://www.nist.gov/sites/default/f...d/jpcrd526.pdf |
|
|
January 12th, 2017, 05:47 PM | #26 | |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Quote:
It seems that the paper states that the viscosity increases with temperature for pure air, water steam and any mix alike. Would you consider viscosity of the oils used in our bikes a form of internal friction between particle layers to keep the fluid moving?
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
|
January 12th, 2017, 06:43 PM | #27 | ||
Guy Who Enjoys Riding
Name: Jim
Location: North Carolina
Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot.
MOTM - Oct '18, Aug '17, Aug '16
|
Quote:
Quote:
|
||
1 out of 1 members found this post helpful. |
January 12th, 2017, 10:47 PM | #28 |
ninjette.org certified postwhore
Name: TC
Location: Hawaii
Join Date: Sep 2013 Motorcycle(s): A lot. Posts: A lot.
|
My understanding of the term "viscosity" is that it's frequently mis-used.
Just to be sure that we are on the same page -- let's imagine a simple example. If one were to fill a cup with water, and another similar cup with a raw egg -- we can all agree that the cup full of raw egg (egg white and yolk) is 'thicker' than the cup full of water. It would take more effort to use a spoon to stir the cup with the egg in it than the cup with water in it. Question -- which is considered "more" viscous? Or "higher viscosity?"
__________________________________________________
Just batshit crazy. All his posts are endless diatribes. Some are actually entertaining but mostly batshit crazy. |
1 out of 1 members found this post helpful. |
January 12th, 2017, 10:49 PM | #29 |
ninjette.org certified postwhore
Name: TC
Location: Hawaii
Join Date: Sep 2013 Motorcycle(s): A lot. Posts: A lot.
|
For what it's worth, if I run 0w-20 oil in my bike -- it's noticeably quicker.
If I run the standard 10w-40 oil in my bike, it's a little slower but engine wear is dramatically reduced. Perhaps that's relevant.
__________________________________________________
Just batshit crazy. All his posts are endless diatribes. Some are actually entertaining but mostly batshit crazy. |
1 out of 1 members found this post helpful. |
January 13th, 2017, 10:41 AM | #30 | |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Quote:
https://en.wikipedia.org/wiki/Viscosity Could you mention examples of good and bad viscosity in our bikes?
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
|
January 13th, 2017, 05:23 PM | #31 |
ninjette.org certified postwhore
Name: .
Location: .
Join Date: Feb 2011 Motorcycle(s): . Posts: Too much.
MOTM - Feb '13, Feb '14
|
|
|
January 13th, 2017, 07:38 PM | #32 |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Glad to have you in this thread, Chone; I have been waiting for your input about the many forms of friction.
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
January 13th, 2017, 09:22 PM | #33 |
ninjette.org certified postwhore
Name: Eric
Location: Iowa City
Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot.
Blog Entries: 54
MOTM - Sep '18, Feb '16
|
This is an interesting thing to think about. Take two lumps
Of metal. Exactly the same weight and density. Form one lump Into a ball. Form the other onto a needle with points at both ends. Now you have two pieces of metal with drastically different shapes . If you drop them both into a thin viscous liquid the needle will move faster. Because the ball has more frontal area and drag at the rear from the way fluids wrap around . But if you use a thicker liquid the needle slows down because there is more surface area along the sides. This friction or drag makes the needle go slower in the thick liquid. Now take the same two shapes and use a medium viscosity liquid. But change the speed of each shape. https://youtu.be/j0rQ4F3f-Ic
__________________________________________________
Top speed 123.369mph. Ohio mile Worlds fastest 250 ninja |
1 out of 1 members found this post helpful. |
January 13th, 2017, 09:23 PM | #34 |
Participant
Name: Dave
Location: South of Seattle
Join Date: Oct 2012 Motorcycle(s): '94 K75 std Posts: Too much.
MOTM - Aug '15
|
Friction and traction are interesting!
|
2 out of 2 members found this post helpful. |
January 13th, 2017, 09:26 PM | #35 |
Participant
Name: Dave
Location: South of Seattle
Join Date: Oct 2012 Motorcycle(s): '94 K75 std Posts: Too much.
MOTM - Aug '15
|
Fluid flow (laminar and turbulent) is really interesting, too.
Last futzed with by dcj13; January 13th, 2017 at 09:28 PM. Reason: Fixed tense. |
2 out of 2 members found this post helpful. |
January 13th, 2017, 09:46 PM | #36 | |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
Quote:
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
|
|
February 5th, 2017, 12:30 PM | #37 |
Daily Ninjette rider
Name: Hernan
Location: Florida
Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot.
MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16
|
A screw thread is a helical structure.
The development of a screw thread when unwound from the body of a screw is an inclined plane in which the inclination of the plane is equal to the helix angle of the thread. If we consider the nut to be like a weight on that inclined plane, then the slope could make that weight slide down by itself. Friction is the force that prevents that from happening. Sufficient torque and locking devices try making that friction sufficiently high to avoid the nut or screw to get loose. Coarse threads mean the slope of the plane is steeper, requiring more friction to avoid auto-unscrewing than fine threads. That is the reason for which fine threads are mainly used in high vibration applications. However, the crest of a coarse thread is stronger than the crest of a fine thread, reason for which coarse threads are use where stronger clamping force is needed. In cases that require even more axial force, the V-shape thread is upgraded to a trapezoidal-shape thread (the type that you see in a bench vise or C-clamp. http://www.boltscience.com/pages/nut...tightening.htm http://www.boltscience.com/pages/vibloose.htm
__________________________________________________
Motofool .................................Never ride faster than your guardian angel can fly "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí |
1 out of 1 members found this post helpful. |
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[roadracingworld.com] - Motorcycling Australia Presents "Champion Chat" With Glenn Al | Ninjette Newsbot | Motorcycling News | 0 | May 14th, 2015 06:40 AM |
[roadracingworld.com] - Motorcycling Australia Presents "Champion Chat" With Former S | Ninjette Newsbot | Motorcycling News | 0 | May 6th, 2015 09:20 AM |
How to "increase" friction zone? | michael38 | 2008 - 2012 Ninja 250R Tech Talk | 8 | May 20th, 2013 08:31 AM |
It's this type of "stunt" that gives the good riders a bad name | Zipster | General Motorcycling Discussion | 37 | February 5th, 2013 07:29 PM |
|
|