Author Topic: Exploding heart in 3, 2, 1...  (Read 12534 times)

Offline SwashBuckling Drunk

  • Assistant Brewer
  • ***
  • Posts: 241
  • Boring, Oregon
Re: Exploding heart in 3, 2, 1...
« Reply #75 on: April 13, 2011, 10:25:07 pm »
Wow, now I know why there are so many cars hitting bikes around Portland.  What a lot of attitudes (bike people AND car people).

I haven't done a lot of street bicycling, but I DID ride a motorcycle for years.  I always drove very defensively in fear of getting hit by a car.  I do see quite a few cyclists that aren't as cautious as they could be.  Of course, many car drivers are just the same.  Having the right of way means squat when you're on a bike and get smashed by a car.

Offline nicneufeld

  • Senior Brewmaster
  • ******
  • Posts: 1049
Re: Exploding heart in 3, 2, 1...
« Reply #76 on: April 14, 2011, 03:04:53 am »
Anybody remember this classic from their youth?

http://www.youtube.com/watch?v=0ZgiVicpZGk


ccarlson

  • Guest
Re: Exploding heart in 3, 2, 1...
« Reply #77 on: April 14, 2011, 03:32:30 am »
Great cartoon. I'm going to mount a set of cross hairs on my hood, so I don't miss the cyclists.  ;D

Offline punatic

  • Official Poobah of No Life. (I Got Ban Hammered by Drew)
  • *********
  • Posts: 4583
  • Puna District, Hawaii Island (UTC -10)
Re: Exploding heart in 3, 2, 1...
« Reply #78 on: April 14, 2011, 03:45:54 am »
Anybody remember this classic from their youth?

http://www.youtube.com/watch?v=0ZgiVicpZGk



OK - you've got me...  Yes, I was one of the original guys in the Goofy costume at WDW in the early 70s.

As it happens, we are having our 40th year Zoo Crew reunion in Orlando the weekend before NHC '11 in San Diego.

I'm not overly excited about traveling to the mainland anymore, but these two events are exerting a strong pull.
There is only one success: to be able to spend your life in your own way.


AHA Life Member #33907

Offline a10t2

  • Official Poobah of No Life. (I Got Ban Hammered by Drew)
  • *********
  • Posts: 4696
  • Ask me why I don't like Chico!
    • SeanTerrill.com
Re: Exploding heart in 3, 2, 1...
« Reply #79 on: April 14, 2011, 07:02:00 am »
Conversely, I believe it is a testament of how amazing humans are that we can conceive and operate vehicles at all.

If you can conceive a vehicle, then that really *is* amazing. ;D
Sent from my Microsoft Bob

Beer is like porn. You can buy it, but it's more fun to make your own.
Refractometer Calculator | Batch Sparging Calculator | Two Mile Brewing Co.

Offline euge

  • I must live here
  • **********
  • Posts: 8023
  • Ego ceruisam ad bibere cervisiam
Re: Exploding heart in 3, 2, 1...
« Reply #80 on: April 14, 2011, 07:29:21 am »
Conversely, I believe it is a testament of how amazing humans are that we can conceive and operate vehicles at all.

If you can conceive a vehicle, then that really *is* amazing. ;D

Exactly! ;D

BTW my motorcycle riding has improved my car-operating skills. Anyone feel the same?
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Laws are spider-webs, which catch the little flies, but cannot hold the big ones. -Anacharsis

Offline Beer Monger

  • Brewer
  • ****
  • Posts: 484
  • ---Michael Dieterle--------- ---Seattle, WA
    • Beer Monger - Adventures In the Wonderful World of Beer.
Re: Exploding heart in 3, 2, 1...
« Reply #81 on: April 14, 2011, 12:56:08 pm »
Conversely, I believe it is a testament of how amazing humans are that we can conceive and operate vehicles at all.

If you can conceive a vehicle, then that really *is* amazing. ;D

Exactly! ;D

BTW my motorcycle riding has improved my car-operating skills. Anyone feel the same?

Absolutely.  IMO, motorcycle riding teaches you the perfect combination of defensive & agressive driving - in other words, knowing when to play things cautious/safe and when to crank the throttle to get yourself up/ahead/away-from/out of a potentially dangerous situation. 

I wish Spring would finally arrive in the northwest (our high today is expected to be 48-49 & rainy), I haven't had my bike out yet this year.  :( 
Beer Monger's Blog
Follow my Beer Monger page on Facebook!

Drink responsibly and stay safe out there.

Offline bluefoxicy

  • Brewer
  • ****
  • Posts: 305
Re: Exploding heart in 3, 2, 1...
« Reply #82 on: April 14, 2011, 02:14:18 pm »

Absolutely.  IMO, motorcycle riding teaches you the perfect combination of defensive & agressive driving - in other words, knowing when to play things cautious/safe and when to crank the throttle to get yourself up/ahead/away-from/out of a potentially dangerous situation. 


That's called a "Trial by Fire."  Learn or die.

"Combining both brakes won't stop you faster"  Yeah, WRONG.  ::)

Only wrong if you can somehow keep the rear wheel fully seated on the ground under MAXIMUM braking force.  I don't mean "Touching but gliding," I mean "Firmly planted."  If what is called a "stoppie" is physically possible, then using only the front brake in the most efficient way possible provides 100% of the maximum stopping power.



You have this kind of braking force up front.  What can the rear wheel possibly add?  The above is too much braking; use less front braking force, just enough to make the rear wheel glide over the surface of the road.

The maximum braking force of the front wheel on an upright bicycle (not motorcycle) is about 0.5g (i.e. 4.9 m/s^2 or 16ft/s^2), while the maximum braking force of the rear wheel alone is 0.1g (i.e. 0.981m/s^2 or 3.2ft/s^2).  The more force applied up front, the more weight comes off the rear wheel, thus the less friction produced by stopping the rear wheel (friction is friction coefficient times perpendicular force), thus at i.e. 0.4g you have absolutely no more than 0.02g stopping force in the back, and 0.42 is less than 0.5.  Be mindful you can lift the rear wheel by the 0.5 mark, so you haven't maximized front brake efficiency until you've eliminated rear wheel braking force entirely.  Maximum stopping force is at roughly 11% slippage in any condition, but the fact that the wheel is able to deadstop and flip the bike over it if the rider slides forward (if you push on the handlebars and stay seated, this likely won't happen) indicates that the front wheel is NOT skidding (at which point there is little braking force).

In various situations, front braking is undesirable.  On bumpy terrain (ill-maintained roads etc), you can throw the bike either forward or in a random direction (loss of control); use partial rear braking.  On long descents down huge hills you can overheat a wheel, inflating a tube beyond maximum pressure and causing a blow; modulate the brakes between front and back to allow heat radiation.  Of course if the front wheel is blown, stop with the rear.  In slippery conditions, more control can be had with some rear braking, sometimes; more braking force can usually be had due to lack of friction limiting efficiency to a point that the rear will not lift off the ground (at least not as soon), and indeed it's the total force that causes slippage (thus the rear wheel can reach more of its maximum braking power than the front wheel, since its maximum braking force is lower).

Motorcycles are not bicycles.  Motorcycles work exactly the same as bicycles; however, they are larger, heavier, faster, have a better contact patch with the ground, etc.  Sam exact dynamics, but the numbers we're using here are much different.  Launching a motorcycle end over end by locking the front brake is easier going 80mph, and seating yourself firmly won't help.  The only reason a bicycle flips is because the rider goes forward into the handlebars; without this momentum, the bicycle's weight distribution with the rider makes flipping a bike on level ground impossible, and difficult coming down hill (wear your helmet).  The bike weighs about 6 pounds; the motorcycle weighs about 6 times what you do.  The motorcycle will not only effectively ignore your weight (puny flesh sack), but also will have much more powerful brakes, much more momentum, and much more raw speed.  In other news, you can't bunny hop a motorcycle by pulling up with your hands and legs.

http://www.amazon.com/gp/product/0262731541/

This is apparently the most up to date casual book on the topic of bicycle and motorcycle dynamics.

Offline Beer Monger

  • Brewer
  • ****
  • Posts: 484
  • ---Michael Dieterle--------- ---Seattle, WA
    • Beer Monger - Adventures In the Wonderful World of Beer.
Re: Exploding heart in 3, 2, 1...
« Reply #83 on: April 14, 2011, 02:22:42 pm »
Motorcycles work exactly the same as bicycles
Dang!  No WONDER I get so fricken tired trying to pedal mine up steep hills!  ;)  lol
Beer Monger's Blog
Follow my Beer Monger page on Facebook!

Drink responsibly and stay safe out there.

Offline bluefoxicy

  • Brewer
  • ****
  • Posts: 305
Re: Exploding heart in 3, 2, 1...
« Reply #84 on: April 14, 2011, 02:46:27 pm »
Motorcycles work exactly the same as bicycles
Dang!  No WONDER I get so fricken tired trying to pedal mine up steep hills!  ;)  lol

You're not backpedaling enough.

Offline EHall

  • Brewmaster
  • *****
  • Posts: 729
Re: Exploding heart in 3, 2, 1...
« Reply #85 on: April 14, 2011, 02:51:12 pm »
Sigh, you had me at 'about 0.5g (i.e. 4.9 m/s^2 or 16ft/s^2), '....
Phoenix, AZ

Offline bluefoxicy

  • Brewer
  • ****
  • Posts: 305
Re: Exploding heart in 3, 2, 1...
« Reply #86 on: April 14, 2011, 03:01:37 pm »
Sigh, you had me at 'about 0.5g (i.e. 4.9 m/s^2 or 16ft/s^2), '....

Acceleration, in terms of acceleration by gravity, which is 9.81m/s^2.  It means that in the first second you're going 9.81m/s, in the second 19.62, in the third 3*9.81, and so on.  Braking is acceleration in the opposite direction, as you're trying to come to a stop and thus need to increase your speed along the vector opposing your current vector of travel.  This is all very complicated, as speed and time and everything are relative (i.e. perhaps the earth is 'moving' and you're 'stopped,' then 'stopping' involves 'accelerating to move with the earth'); so we just call this "Slowing down" and "Stopping" based on arbitrary perspective.  Still, the act of going from 0-60 is mathematically and physically equivalent to the act of going from 60-0, even though we call them different things.

Didn't you study advanced physics in high school like the rest of us?  (Basic biology, chemistry up through some organic and nuclear chemistry, and physics were all mandatory study in my high school; I don't remember much, and intend to restudy basic algebra in a better, more permanent fashion to make these topics more accessible to restudy.)

Offline denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 24839
  • Noti OR [1991.4, 287.6deg] AR
    • Dennybrew
Re: Exploding heart in 3, 2, 1...
« Reply #87 on: April 14, 2011, 03:03:33 pm »
I like turtles.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline EHall

  • Brewmaster
  • *****
  • Posts: 729
Re: Exploding heart in 3, 2, 1...
« Reply #88 on: April 14, 2011, 03:06:10 pm »
Sigh, you had me at 'about 0.5g (i.e. 4.9 m/s^2 or 16ft/s^2), '....

Acceleration, in terms of acceleration by gravity, which is 9.81m/s^2.  It means that in the first second you're going 9.81m/s, in the second 19.62, in the third 3*9.81, and so on.  Braking is acceleration in the opposite direction, as you're trying to come to a stop and thus need to increase your speed along the vector opposing your current vector of travel.  This is all very complicated, as speed and time and everything are relative (i.e. perhaps the earth is 'moving' and you're 'stopped,' then 'stopping' involves 'accelerating to move with the earth'); so we just call this "Slowing down" and "Stopping" based on arbitrary perspective.  Still, the act of going from 0-60 is mathematically and physically equivalent to the act of going from 60-0, even though we call them different things.

Didn't you study advanced physics in high school like the rest of us?  (Basic biology, chemistry up through some organic and nuclear chemistry, and physics were all mandatory study in my high school; I don't remember much, and intend to restudy basic algebra in a better, more permanent fashion to make these topics more accessible to restudy.)

You're such a flirt! ::)
Phoenix, AZ

Offline beersk

  • Official Poobah of No Life. (I Got Ban Hammered by Drew)
  • *********
  • Posts: 3719
  • In the night!
Re: Exploding heart in 3, 2, 1...
« Reply #89 on: April 14, 2011, 03:11:24 pm »
Jesse