Braking by Nick Ienatsch

Discussion in 'The Perfect Line and Other Riding Myths' started by outlaws justice, Jul 3, 2012.

  1. wmfleet2

    wmfleet2 Long timer

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  2. Harvey Krumpet

    Harvey Krumpet Been here awhile

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    Your out there practising? :clap:freaky
    Check out the gymkhana thread. No, seriously. It's a mad thing, not the thread, gymkhana.
  3. atomicalex

    atomicalex silly aluminum boxes

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    ...putts off to read the Gymkhana thread....
  4. bungie4

    bungie4 Frostback

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    I've had more than a passing interest in gymkhana for a while now. I'm so glad to see a moto-sport that anybody can take part in without the high dollar investment.

    Little story, a few years ago I was on a charity ride (don't do those anymore) where I was stuck in a parade of chrome turtles in parking lot. Each and everyone of them were duck paddling along. Well we passed directly in front of 4 motor cops. I didn't realize it at the time but I was the only one who rode past, and made a Uturn into a parking spot at sub walking speeds - with my feet on the pegs the whole time.

    2 of the cops come over to look at my bike and mentioned I was the only one who did it properly. Woo. Anyway after the ride the cop who supervisors all the training came back over to me and offered me to follow him back to the station and take a stab at there training course.

    "Good PR this" I'm thinkiing

    Well, one look at the course had me thinking this is a bad idea, especially on the FJR. Long story short I managed to do the whole course without putting a foot down. But I did clip one cone with my pannier. Still, f'n eh!

    I've been riding for 30+ years. You can always learn new skills and that helps keep the pursuit fresh.
  5. crofrog

    crofrog Long timer

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    I'm confused what's the point of keeping your suspension up in the travel?

    Under hard braking the forks on my SM and adventure use about 8" (stock springs) and my SMR uses about 6"

    And once I get them into the stroke some I use trail braking to keep them there while the cornering forces take over to hold them down for the rest of the turn. Although they both do extend some as the braking load comes off of them.
  6. bungie4

    bungie4 Frostback

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    It's an exercise in being smooth on the throttle and the brake SIMULTANEOUSLY.

    Which begs the question why?

    Your suspension works best at its mid point. But entering a turn hard on the brakes transfers all the weight up front, which changes your steering geometry (making it quicker) as you release the brakes your front suspension extends, slowing down the geometry. As you roll on the throttle exiting the corner, your suspension, front and rear, extends still further, further slowing down the geometry.

    All this fork movement really unsettles the bike. and depending on the situation, leaves the suspension unable to cope properly with road irregularities or corrections.

    By using the brakes AND throttle at the same time, it's possible to keep the suspension in the sweet sport of suspension travel greatly stabilizing the bike all through out a turn.

    Side benefit is the potentially increased ground clearance because your suspension isn't effectively collapsed when you need it the most.
  7. Mambo Dave

    Mambo Dave Backyard Adventurer

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    I have trail braked on the street when entering corners way, way too fast - so for me it's always been an emergency backup plan. In the instances I've done it I've never lost a bike or crashed as it was looking like I might up until I kept braking.

    But to me that is relying on traction (or traction coefficients) that many times just aren't there when riding in states like this one where, with no state inspection, vehicles of all ages, that leak all kinds of fluids, use the same roads as I do.

    Braking into or through a turn can be done, yes, but it sure isn't something to rely upon on many public roads. And if you're wondering, this isn't coming from someone who rides like a grandpa on the streets... the back roads of Pennsylvania used to be my own private course for my ZX-7R, but trail braking was just an emergency parachute.

    Great to practice for track days or for emergencies, but there will be more wrecked street bikes out there if riders start entering corners with more speed and expect that level of traction to be linear like it is on most tracks.
  8. TheWall

    TheWall 0 miles and counting

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    Okay, I understand and agree with that, with the possible exception that rolling on the throttle extends your rear suspension. I understand what was said about tightening the chain pulls the rear suspension upwards, but you've also got weight shift to the rear during acceleration, which compresses the rear suspension. However, which force is the greatest (and therefore, which direction the suspension adjusts) is not settled in my mind. Please note, I'm not saying you're wrong -- I'm just saying I can see an argument either way, so I'd like to test it and find out for myself. I think I'll need to rig up a camera and do some testing next spring. I'm weird like that :D

    I can see how having the suspension extending and compressing throughout the maneuver can make it difficult to control the bike precisely. I can also see how a skilled rider could use the shortened steering geometry at the turn entry to make a tighter turn than would be possible otherwise. In fact, that's one of the tricks of the trade that the really good riders (not me :cry ...yet) use over in that other thread to make the really tight turns in a GP8, for example. But it takes a while to master that skill, and lots of people drop their bikes during the mastery process, so it's probably not a great technique to be experimenting with in traffic :deal
  9. B.Curvin

    B.Curvin Feral Chia tamer

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    I ride 400 to 500 miles a week. I trail brake (front) into the vast majority of corners I negotiate, every single day. I've only tucked the front on pavement once in my life...........in a race.......on a racetrack. :lol3

    I've been riding for 35 years.

    [​IMG]

    Oops. :D

    [​IMG]

    [​IMG]





  10. Mambo Dave

    Mambo Dave Backyard Adventurer

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    And I respect that, but I also don't understand how it can be relied upon in states like Ohio and Florida where old oil/coolant/cargo leaking vehicles are too common (or in Pennsylvania where chip seal road corners accumulate gravel), and traction in corners too unpredictable. Could I get away with it for a year? Probably. Year after year? Not worth the price to bet on.

    I, too, was riding 400 to 500 miles a week there for over a year and a half... every week. On those roads I could get away with more in all types of temps and conditions as I knew them really well, and was generally up on new changes to the surfaces.

    But for simple sport riding where we didn't take the same routes, ever, up in PA... relying on trail braking will catch you within the year on roads you don't know. You simply will not have that 3% or 10% of traction left in the corner on hot and bubbly tar roads, or on loose aggregate, or on left-over traction laid down on previously icy roads.

    So, again, this is back to the predictable-ness of tracks, and courses we take every day (or joy ride on during weekends) are far more like race tracks than exploratory sport riding can expect.
  11. crofrog

    crofrog Long timer

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    The problem with fork movement isn't that it moves it's when it "pogo's" you want to get your forks compressed under braking which helps the bike turn in and through turn in so you don't suddenly unweight the front coming off the brakes and have them smoothly extend as you get on the gas and come out of the corner. The goal is have them go down one time and come up one time smoothly each corner, and not go up down up down etc

    That I agree with but it has nothing to do with only using 1" of travel past sag.

    Well, nothing but spring rate determines where you end up in your travel for a steady state cornering load. To use less travel you either get stiffer springs or you don't brake / turn as hard.

    If I tried to ride around only using 1" of travel I'd be _very_ slow.

    Rossi hard on the brakes
    [​IMG]

    Jorge mid-corner
    [​IMG]

    Casey Stoner accelerating out of a corner (gives you a good idea of total travel available to the rider
    [​IMG]


    So could you explain why you where trying to use such a small amount of travel? Or what the actual drill is you where doing?

    Also to the guy who wasn't sure about the suspension extending under acceleration, look at the distance between the bottom of the tire back tire and the bottom of the bellypan between the mid-corner and the corner exit shot. The bike leaving the corner is doing a wheelie so it has 100% load transfer to the back wheel and the suspension is almost if not fully topped out.
  12. crofrog

    crofrog Long timer

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    Trail braking and being near the limits of tire adhesion are 2 different things, and sliding the front doesn't mean you're crashing.
  13. Wraith Rider

    Wraith Rider Banned

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    What brings the conclusion that trail braking on public roads is just for fun, because if you have left a reasonable amount of traction you don't need to brake at all.
  14. crofrog

    crofrog Long timer

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    Because you can use the trail braking to get you to the line you want to be on and be no where near the limits of adhesion or to use less lean angle, or make the ride really smooth.

    If you frequently ride around on public roads with the bike pushing and sliding it's a matter of time until you get caught out.
  15. TheWall

    TheWall 0 miles and counting

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    Great analysis -- thanks for posting that! And yeah, the Ducati certainly looks like the rear suspension has extended compared to the Yamaha in the second photo. Interesting...
  16. Andrew011

    Andrew011 Tourist

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    On public roads there is an element of possible surprise in the corner (wherever you can't see the road far enough ahead). I find it easier to react in these situations if trail braking, it is easier for me to tighten the turn if needed, to instantly slow down if needed, or to quickly change direction, because the front is partially loaded and the grip is already there.

    I don't think of trail braking as "an invitation" or "green light" for faster entries in the corners. For me it is like a preemptive measure of giving some grip to the front, until I see the clear exit and roll on the throttle.
  17. B.Curvin

    B.Curvin Feral Chia tamer

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    :thumb


    and :thumb
  18. Harvey Krumpet

    Harvey Krumpet Been here awhile

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    This for me. ^^^ We have a lot of twisty roads & constantly changing surfaces so I often find myself trail braking into corners so I have control of the bikes attitude until I can see my apex and clear exit, it also allows me to instantly tighten or widen my turn & should I have to avoid an oncoming vehicle on my side of the road, which is common, I can do so quickly & smoothly by gently increasing my braking or accelerating by releasing the brakes as I look for an "exit".
    The trail braking is very subtle, I have never had an issue with a bad road surface, gravel etc despite hitting plenty of it but I have had the time to react correctly and not unsettle the bike.
  19. bungie4

    bungie4 Frostback

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    I'll say it again. It's a practice exercise. I never suggested you should only ever use only 1" of suspension travel. In fact, I explicitly said the sweet spot was mid-travel.

    If you learn to use both TOGETHER properly, you eliminate any chance for 'pogoing'. Do it improperly and you'll be worse off.

    I'm done.
  20. TheWall

    TheWall 0 miles and counting

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    As an exercise to see how smoothly you are applying throttle and brake, I take it? Makes sense to me :clap Might be fun to practice this in the parking lot with tennis ball "cones" to help break the habit of grabbing at brakes, clutch or throttle.