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Engine braking questions

Discussion in 'Motorcycle Talk' started by blakegaston, May 23, 2012.

  1. When engine braking is occurring, is it the same as using the rear brake?

    I had my first track day on Friday, and am now obsessed with trying to figure out everything about how bikes work, fastest lines, how and when to brake/shift, etc. Still curious about engine braking, and how it can be useful.


    Also, when downshifting after a long straight, you go hard on the front brake, but whats the best way to downshift?

    For example, going from 6th to 2nd.

    I found myself doing this, but I know its not a great way.

    150mph, coming up to corner. Brake. Tap tap tap from 6th to 2nd with clutch in. When in second, grab a handful of throttle, rev it up, and then release clutch, and roll throttle through corner.

    I found it too time consuming to rev match downshift each gear, so I just do one big rev match at the end. :/

    But I know if I do it per gear, I can utilize the engine braking in addition to hard on the front brakes, and get more stopping power.

    Would dumping the clutch each gear be better? eg:

    150mph, hard on brakes. clutch in, 5th gear, dump it. Clutch in 4th gear, dump it, etc etc.


    Thanks :)
     
  2. First...don't dump your clutch, especially at speed. It makes your rear tire go all squirrelly, and unbalances your suspension, and that's really bad when you are tipping into a corner. Ease your clutch out smoothly...it's possible, with practice, to do it quickly and smoothly so it keeps the bike stable and happy.

    As for the whole engine braking thing, according to Keith Code, brakes are for stopping and engine is for going. Doesn't make sense to burn out your engine sooner when brakes are way cheaper. But that's just one man's opinion, I'm sure there are more than a few that are contradictory and just as valid.

    Skipping gears...I personally don't do it because I'm terrified I'm going to lose count and end up bouncing off the limiter.
     

  3. Deven

    Deven Dee-von White

    ...slipper clutch?
     
  4. Before slipper clutches people had to learn to revmatch while braking. Slipper clutches alleviate having to do this.

    And the whole skipping gears + doing a big rev match at the end is just asking to end in a very bad way.
     
  5. R6's have slipper clutches, but they're definitely not the best. You should be in third or fourth gear for turn one at the Ridge, depending on your gearing. The gearing on my bike (stock) only allowed me to hit 140, which is top of fourth, drop a gear and hit turn one, drop one more for 2, and back on the gas hard out of three. Hope that helps some.
     
  6. DGA

    DGA Moderator

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    Like previously said, no coasting at the track and you've got a slipper clutch.
     
  7. AFAIK, a rev limiter is only effective when accelerating. You can downshift too far and go past the redline pretty easily and risk major engine damage.

    As stated, if you dont have a good slipper clutch, it is best to practice very hard with a smooth release and downshifts. If downshifting several gears, this is CRITICAL.
     
  8. As you brake into the corner you match engine speed to gear so you are ready to exit the corner...brakes for stopping....engine for going. That being said you need to have maintenance throttle going in...that keeps everything rolling and imparts feedback. yes things get busy...remember smooth is fast
     
  9. T1 at ridge is 4th?? Its what, a 70-80mph turn? Id be a lot closer to my powerband in 2nd/3rd, wouldnt I?

    Ugh, so much to learn.
     
  10. Turn 1 can be taken much faster than that. Until you get to that skill level, use the advice already given in the thread to smoothly downshift to the speed you're comfortable with. Are you short shifting to get to sixth?
     
  11. Short shifting? I feel kinda weird using the clutch going that fast, since its hard to let off the throttle smoothly enough at 130mph+

    So I let the throttle go just a smidge, and kick it into the next gear. Its not always smooth though, but its better/faster than pulling the clutch in, going into the next gear, and letting it out... especially because at that speed I find I don't get off the throttle enough, and am still giving it gas with clutch in, so when i let clutch out, rpms are higher than they should be, and I jerk a bit. So I just clutchless shift.

    I know, I have a lot to work on :/
     
  12. No idea how fast I was actually going... had my speedo taped up :p. It felt fast:mfclap:
     
  13. Short shifting = shifting a a lower than optimum RPM for acceleration. You may do this if traction isn't very good or to keep the front wheel down on a 1-2 shift.... there is no reason to short shift through the gears on the front straight @ the ridge.

    Clutchless upshifting is another issue altogether, and it sounds like you have the idea just need to work on getting it smooth. If you didn't know, applying pressure to the shift lever before your shift point while you are at WOT and holding it will make the bike shift instantly as soon as you let off the throttle and unload the gears in the transmission. THis allows you to make your shift with a quick WOT - slight let off - WOT motion of the throttle.

    On the downshifting process.... I don't have a slipper clutch, so I do blip the throttle and let out the clutch on each shift. You will find with more time on the track that there is plenty of time to do this in the heavy braking zone before turn-in. I think your attention is just divided on too many tasks as a new track rider, and it will get better the more laps you turn.
     
    evander likes this.
  14. Even with a slipper clutch I still blip the throttle and let go smoothly when downshifting. On both CBR1000rr's I owned, as well as several R6's I rode at the YCRS, I could still get the back end to get all funky if I just dumped the clutch. Since every bike I rode before the last few didn't have slippers, I suppose i'm just used to it.
     
  15. Just a suggestion...I don't have a slipper, but I know a lot of guys that start w/ slippers and never learn to ride without one. So they become reliant upon the slipper to correct every time they shift.

    So..I would recommend riding like you don't have one, learn to be smooth on the clutch, how to revmatch, etc. It will make you a smoother and faster rider. And if you do screw up, the slipper (generally) will have a smaller correction to make, again contributing to your smoothness.

    Edit (new thought): I'm sure your instructors told you this, but I'll reiterate it since you are brand-new to the track. Only focus on one thing at a time, you can't focus on improving everything at once...there is just too much to learn. Pick one thing, like shifting...learn it, love it, master it...then move on to the next thing.
     
    Last edited: May 23, 2012
  16. Watch, "a twist of the wrist" until you're sick of it, then watch it again. You probably wont understand most of it, but after time it will start to make sense. Keep doing track days, keep asking questions and get someone to follow you around for a session. sounds like youre getting hooked! nice!
     
  17. Im unhealthily hooked. Im doing whatever I can to get back down for another romping. Ill go to any track day if I can find transport haha. Im going to sell my r6 and get a truck and more gear.
     
  18. This
     
  19. This has been responsible for many a catastrophic engine failure in cars.
    I would imagine the same is true with bikes, but I suppose it's likely that it's caused more wad ups than blown up engines.
     
  20. I may not understand the terminology completely but the skip gears + rev match scenario is when like the OP asked, just to clarify. Dropping gears with clutch in, pop the throttle to drop the rev's and ease the clutch back into engagement in gear of choice?

    How is this bad if that's the case?