Practicing emergency braking... marks left on pavement?

Discussion in 'The Perfect Line and Other Riding Myths' started by opticalmace, May 11, 2013.

  1. opticalmace

    opticalmace Been here awhile

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    Hi all,

    I am a relatively new rider and I have been trying to practice my emergency braking. I am only using my front brake for now (on the street I use both). I'm on a Ninja 250R.

    I do it in a local parking lot and there appears to be (unbroken) rubber streaks/marks left after I do a run.

    Is this normal? I really don't think I'm locking the front. Kind of spooked me a little when I noticed it. :eek1

    Thanks!
    #1
  2. AzItLies

    AzItLies Been here awhile

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    Sure, that's normal. I'd suggest getting use to using both brakes to stop, as that is your full stopping power. Practice that instead of just front or back.

    Cheers
    #2
  3. shaddix

    shaddix Banned

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    What bike are you on
    #3
  4. joexr

    joexr Banned

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    If you're doing the practice on a coated parking lot , the surface is not an acurate representation of asphalt. The coated asphalt is slicker.:deal
    #4
  5. opticalmace

    opticalmace Been here awhile

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    Oh, really? Had no idea. Thanks for the tip.

    2012 Ninja 250R.
    #5
  6. Capt Crash

    Capt Crash Benevolent Despot

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    It could be a sign of a thing called "impending skid" where your tire is still turning but not as fast as you are going.

    Or it could be your skidding the rear and don't realize it, or you're not pulling the clutch in fully...

    A better indication of how you're doing is to measure speed and distance.

    http://youtu.be/imrAbLNeFe4
    #6
  7. txwanderer

    txwanderer Been here awhile

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    Friction is your friend. Sounds like you are close to the threshold of grip and slip. Now that you know where that is,,,,,,,,,,,,,,

    I would suggest as someone else did, to use both brakes, try it on different surfaces and throw a bucket or two of water out there just to add to the mix.

    Congrats for actually practicing things that will keep you alive.

    Cheers
    #7
  8. Fajita Dave

    Fajita Dave Been here awhile

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    If you're using the Ninja 250s full braking potential the rear tire will lift off the ground if you're on good pavement which makes the rear brake useless. Those lines are either from a sealant on the parking lot or you are right on the edge of the bikes braking limits. You will know it when the front tire locks. Usually the handlebars will turn one way (most of the time its left from rider squeezing/pushing on the right brake lever) and the front end gets a vague feeling of not being connected to the pavement anymore. As long as you let off the front brake the bike will recover on its own for the most part. A lot of people end up freezing when the front tire locks and never let off the front brake.

    You should still practice with the rear brake for wet pavement, dirt, or any other situation that is less then optimal traction. But for what you're doing its fine to just use the front brake and get comfortable with heavy braking. For the record on my sportbike the rear brake has been pretty much useless unless it was in gravel or dirt. Even on wet pavement the front brake gets the rear end so light the rear brake doesn't slow you down any quicker.

    If you can get access to a dirtbike and practice braking off-road it would make learning much easier. Tire lock ups are much more forgiving in dirt or grass but you'll get to know how it feels and how to recover from it. If you drop a dirtbike its no big deal compared to the fairings on your Ninja.
    #8
  9. lnewqban

    lnewqban Ninjetter

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    I also practice emergency braking and Moto Gymkhana with my Ninja 250 and I agree with Fajita's post above.

    When I repeat a figure 8 several times on the same area of the parking lot where I practice, a darker line shows a huge number 8 on the pavement.

    Yes, we leave little particles of rubber on the road each time that the contact patch feels some sheering load (lean or brake).

    Kudos to you for practicing: keep looking far away, grip the tank hard with your knees and focus on keeping a perfect balance all the way to a full stop.
    #9
  10. opticalmace

    opticalmace Been here awhile

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    Thanks guys, this info is really useful!

    About threshold braking, I used to (downhill) mountain bike a lot. My bikes had very strong hydraulic disk brakes. I think it is probably helping a bit, though it's certainly a different feeling slowing down several hundred pounds!
    #10
  11. Barry

    Barry Just Beastly

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    Mountain biking absolutely applies to riding your moto. Good on ya for practicing. Keep it up.

    Barry
    #11
  12. Tripped1

    Tripped1 Bitch called me a feminist.

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    Nope, not locking the front just pulling off a little bit off rubber, you would know if you managed to lock the front.

    Congrats, you have discovered the threshold of traction, a lot of riders never actually feel it.
    #12
  13. Capt Crash

    Capt Crash Benevolent Despot

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    Just a splash of cool water. You need to be careful when you're practicing braking because it's very easy to convince yourself you're really getting it done when you're not. Subjectively deciding you're at threshold without a speed/distance check means you may be training yourself to under perform while braking.
    #13
  14. Tripped1

    Tripped1 Bitch called me a feminist.

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    If you are leaving blackies with the front wheel there isn't very much left, you can adjust the attack and add a bit of rear initially. That is about it.
    #14
  15. Capt Crash

    Capt Crash Benevolent Despot

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    Ahhhh...I only weight 185 pounds. I know this because I feel strongly that I weigh 185 aNd the belt I wear is the same style I've always worn. I don't need a scale...yeah, that's the ticket.

    What's the harm in making an objective measure?
    #15
  16. opticalmace

    opticalmace Been here awhile

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    Good tip about measuring the braking distances. As a scientist-in-training I appreciate the objectivity.

    That is definitely what I am going to try next.
    #16
  17. Capt Crash

    Capt Crash Benevolent Despot

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    Yes. Objective measures. DAMN! Scale says I go 235...must be broken...
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  18. Fajita Dave

    Fajita Dave Been here awhile

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    When I first got my street bike (after I hit a deer with it) I practiced emergency braking religiously for a while. I measured the distance of each stop simply to keep track of my progress.

    While doing that on clean pavement I felt like I couldn't brake any harder because it would just hover the rear tire across the ground practically from start to finish (in an emergency it never works out that smooth). I didn't think I could stop any faster then that... until I started gripping the tank with my knees harder instead of weighting the handlebars. This kept the rear tire on the ground a little longer and shaved a few more feet off my stopping distances from 60mph.

    The mountain bike experience will definitely help! Riding downhill I'm sure you've felt the front tire start to wash out from to much front brake. Its the same feeling; theres just a lot more mass involved that takes getting used to.
    #18
  19. MADurstewitz

    MADurstewitz MADMark

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    Downshifting will radically reduce your stopping distance. It may save your life one day.
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  20. Barry

    Barry Just Beastly

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    How exactly does downshifting give you more stopping power than using the rear (and front) brake to maximum effectiveness?
    #20