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Oct 17th 2016, 03:18 PM   #1
 
  Jan 2016
  Pasco

  2016 K1300S
Cornering: Radius Equals MPH Equation

I just read another great article by Nick Ienatsch in the November 2016 issue of Cycle World. The article is about dealing with the flat-land problem of freeway on- and off-ramps. He addresses several points about the long corners on freeway ramps, but the first point is the "radius equals mph equation." The essence of this point is that, "increasing speed opens the bike's cornering radius and forces it to run wider while decreasing speed tightens the radius." He also speaks to using light braking to accomplish controlled reductions in speed during cornering. This "steering with the throttle/brake" is a repeatable and adjustable way to handle corner radius changes in freeway ramps or any other corner that you don't already know by heart.
Anyway, it is a very worthwhile article, and it is short (for those of us with short attention spans).
Oct 17th 2016, 04:07 PM   #2
 Cougar's Avatar
 
  Jan 2016
  Richland

  Yamaha FZ1, KTM Super Duke GT, Yamaha FJR, Yamaha XS650
Quote:
Originally Posted by Mr Yuk
I just read another great article by Nick Ienatsch in the November 2016 issue of Cycle World. The article is about dealing with the flat-land problem of freeway on- and off-ramps. He addresses several points about the long corners on freeway ramps, but the first point is the "radius equals mph equation." The essence of this point is that, "increasing speed opens the bike's cornering radius and forces it to run wider while decreasing speed tightens the radius." He also speaks to using light braking to accomplish controlled reductions in speed during cornering. This "steering with the throttle/brake" is a repeatable and adjustable way to handle corner radius changes in freeway ramps or any other corner that you don't already know by heart.
Anyway, it is a very worthwhile article, and it is short (for those of us with short attention spans).
Thanks Rod. I have that issue but I haven't started reading it yet.
Oct 18th 2016, 05:03 PM   #3
 
  Jul 2016
  tigard

  2013 Ninja 1000
I just read that one. Not every state has natural curves to play on. I never thought about it much but one of the few places in Florida to play around is on the freeway on- and off- ramps. In this case it can mean 270 + degree sweeping curves. So guys go railing on these turns with concrete or dropoffs along the sides. When the radius decreases it goes bad in a hurry.....especially if there's a gator in the ditch. LOL I think he's referring to trail-braking when he talks about "steering with the throttle/brake"
Oct 18th 2016, 09:33 PM   #4
 
  Jan 2016
  Pasco

  2016 K1300S
Quote:
Originally Posted by mxmike
I just read that one. Not every state has natural curves to play on. I never thought about it much but one of the few places in Florida to play around is on the freeway on- and off- ramps. In this case it can mean 270 + degree sweeping curves. So guys go railing on these turns with concrete or dropoffs along the sides. When the radius decreases it goes bad in a hurry.....especially if there's a gator in the ditch. LOL I think he's referring to trail-braking when he talks about "steering with the throttle/brake"
Yep, the article talks about the dangers of getting frisky on freeway ramps, but you correctly point out that gators in the ditches can be an added hazard. I also agree that trail-braking is one of the things he is talking about with "steering with the throttle/brake," but I think it also includes adding throttle to open your bike's cornering radius to match the increasing radius of the corner near the exit.
Oct 18th 2016, 09:56 PM   #5
 wooden's Avatar
 
  Jan 2016
  PDX

  '14 St3R, '05 DR650
If you need to read an article to understand that "higher speed = wider turning radius," please stay off the road.
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Oct 19th 2016, 04:08 PM   #6
 
  Jan 2016
  Pasco

  2016 K1300S
Quote:
Originally Posted by wooden
If you need to read an article to understand that "higher speed = wider turning radius," please stay off the road.
I can see that I did not explain this very well. The main point he is making in the article is not the very simple physics that faster speed causes the bike to go wider and slower speed causes the bike to turn in. It is that you can USE this simple physics to add to your control of cornering line. This is contrary to the advice of some riding schools that teach, "accelerate through the entire corner", or "slow in - fast out", which can be particular problems with long 270+ corners in freeway ramps, especially if the corner tightens up part way through the ramp. There are plenty of riders who believe the advice of accelerating through the entire corner. I did, 25 years ago when it was taught to me at a highly respected riding school. I abandoned that advice after taking a riding course from Nick Ienatsch many years ago. I'm hopeful that sharing Nick Ienatsch's advice will be helpful to some riders, somewhere. It certainly won't be helpful to all riders.
Oct 19th 2016, 06:02 PM   #7
 
  May 2016
  SW Portland

Quote:
Originally Posted by Mr Yuk
I can see that I did not explain this very well. The main point he is making in the article is not the very simple physics that faster speed causes the bike to go wider and slower speed causes the bike to turn in. It is that you can USE this simple physics to add to your control of cornering line. This is contrary to the advice of some riding schools that teach, "accelerate through the entire corner", or "slow in - fast out", which can be particular problems with long 270+ corners in freeway ramps, especially if the corner tightens up part way through the ramp. There are plenty of riders who believe the advice of accelerating through the entire corner. I did, 25 years ago when it was taught to me at a highly respected riding school. I abandoned that advice after taking a riding course from Nick Ienatsch many years ago. I'm hopeful that sharing Nick Ienatsch's advice will be helpful to some riders, somewhere. It certainly won't be helpful to all riders.
IMHO, I think you are over-simplifying the very dynamic nature of cornering on a motorcycle. But then again, I don't feel like I really understand the point you are trying to make
Oct 20th 2016, 11:05 AM   #8
bcj
 bcj's Avatar
 
  Jan 2016
  teh rock

  K1200RS SV650
e = M otor c ycles*
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Oct 20th 2016, 09:19 PM   #9
 Wrench's Avatar
 
  Jan 2016
  West Richland, WA

Once the peg touches the ground, I like to use it to slide the rear around. Allows for sharper turning radius at higher speeds without requiring more lean angle.
Oct 21st 2016, 09:11 AM   #10
 SmokeyMcNug's Avatar
 
  May 2016
  Olympia, WA

  1996 Kat 600 "Ras-tana"
You have pegs?!?! lucky bastard. i just stiff leg it on corners anyways.
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