Double clutching the downshift.

Discussion in 'Hangar Talk' started by Arnold, Oct 15, 2020.

  1. Arnold

    Arnold Cleared for Takeoff

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    I find this video fascinating for many reasons. But if you go to 3:35 and watch carefully you'll see a Boss Woman double clutching the downshift. I've been to Gobychettipolyam and saw many of the scenes you see here. The most striking to me, besides the downshift, is the brief shot of the classroom where the kids must sit on the floor and the teacher's unbelievable penmanship. How the other half lives.

     
  2. steingar

    steingar Taxi to Parking

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    The gorgeous video of that wonderfully exotic and beautiful land and all you see is a lady double clutching Odin knows what vehicle?
     
  3. Arnold

    Arnold Cleared for Takeoff

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    First, it was a lovely downshift. Second, didn't you read my first sentence?:D
     
  4. MauleSkinner

    MauleSkinner Final Approach

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    My grandma was told to teach cursive only and not print because of her penmanship.

    One of her students switched schools in the second grade and got in trouble for “showing off” because the new school didn’t get to cursive until the third grade.

    And yes, I appreciate the downshift...the driver knew exactly what rpm she needed.
     
  5. Sac Arrow

    Sac Arrow Touchdown! Greaser!

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    Bro do you even lift
    Nobody double clutches on a downshift.
     
  6. MauleSkinner

    MauleSkinner Final Approach

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    When do they double clutch in your world?
     
  7. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser! PoA Supporter

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    Except when they have a non-syncromesh transmission.
     
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  8. Arnold

    Arnold Cleared for Takeoff

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    Or when they want to have power coming out of a corner. Or use engine braking to slow without burning up the clutch. Or going up a steep hill.
     
  9. 455 Bravo Uniform

    455 Bravo Uniform En-Route

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    F a clutch, just rip it
     
  10. MauleSkinner

    MauleSkinner Final Approach

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    FIFY. :)
     
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  11. steingar

    steingar Taxi to Parking

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    I don't tend to downshift much except emergencies. Brakes are wear items, clutch plates not so much.
     
  12. MauleSkinner

    MauleSkinner Final Approach

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    All well and good if you’re driving something/somewhere where brakes will be adequate.
    upload_2020-10-15_10-12-9.jpeg
     
  13. Arnold

    Arnold Cleared for Takeoff

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    May as well have an automatic.
     
  14. Juliet Hotel

    Juliet Hotel Pattern Altitude

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    How do you know she's downshifting? Either way she's driving a truck, double clutching is how all shifting is done with those transmissions unless you're good like me and just float the gears with no clutch. :D
     
  15. kgruber

    kgruber En-Route

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    There is no reason to double-clutch when upshifting.
    Only beginners "rev-match." Or even worse just let the synchros wear and jolt.

    Double-clutch all downshifts here....................!!!
    Smoooooothe..............old-timer.

    [​IMG]
     
  16. MuseChaser

    MuseChaser Pattern Altitude

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    Rev match. You'll only wear out your clutch if you're doing it wrong. In over a million miles of driving manual cars, taking four of my cars to well over 200K, I've never had to replace a clutch. Not once.
     
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  17. MuseChaser

    MuseChaser Pattern Altitude

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    ROFL... because of the timing of our posts. Always willing to learn. When I downshift (meaning, going from fourth to third preparing to accelerate through a turn, for instance), I always blip the gas to get the engine revs up to an appropriate speed for the new gear before letting the clutch out. Makes for a smoother transition and less wear, no? Are we talking about two different things? Would love to hear more about your statement. Seriously. No snark... always interested in becoming better at anything I do.
     
  18. Dan Thomas

    Dan Thomas Final Approach

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    240,000 km on my Ranger (150,000 miles) and its clutch is still fine. Downshifting all the time.

    If fact, when we were young we were proud of our ability to shift both ways without using the clutch.
     
  19. steingar

    steingar Taxi to Parking

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    To decelerate a vehicle you need to introduce some sort of drag. That drag can come from either the clutch or the brake. There is no free lunch.
     
  20. PaulS

    PaulS Touchdown! Greaser!

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    Best scene of the video, that lady is a boss.
     
  21. weilke

    weilke Touchdown! Greaser!

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    The drag comes from spinning the engine (with or without an engine brake), not from creating friction on the clutch.
     
  22. steingar

    steingar Taxi to Parking

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    You can't shift without creating some friction, especially if you're down shifting. Hey, you do you and I'll do me.
     
  23. PaulS

    PaulS Touchdown! Greaser!

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    Nothing worse than watching someone hold a car in place on a hill by slipping the clutch.
     
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  24. MuseChaser

    MuseChaser Pattern Altitude

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    The drag comes from engine braking in a lower gear, not the clutch.
     
  25. Zeldman

    Zeldman Touchdown! Greaser!

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    The clutch is only needed for starting from a stop, not for shifting up or down.

    And yeah, the first few flight lessons I would stomp the left rudder pedal before starting the engine....
     
  26. Bill

    Bill Touchdown! Greaser! PoA Supporter

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    Well, that and watching this thread devolve.
     
  27. flyingbrit

    flyingbrit Pre-takeoff checklist

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    So you make turns at intersections in top gear?
     
  28. steingar

    steingar Taxi to Parking

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    No, I make stops with the engine out of gear and the throttle at neutral. How the hell do you do it?
     
  29. CJones

    CJones Final Approach

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    To pass the Class A CDL test in Iowa 15-20 years ago, you had to demonstrate shifting up and down through all gears. If you coasted more than one truck+trailer length while not in gear, it could be considered a fail.

    After a few days of grind-it-till-you-find-it, I got to the point that I would only use the clutch when starting from a dead stop or coming to a dead stop. Shifting up and down through all 13 gears was done with left foot on the floor (no clutch needed).

    In the Jeep, it has a different style clutch and it doesn't like to no-clutch shift. Still, I always use downshift to help with braking - oversized tires kill brake pads in no time. Clutch plates only wear out when you're riding the clutch partially engaged - once the plates are locked, they don't move/wear.
     
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  30. Shawn

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    I had a CDL for a while since I owned a semi for my company...floating the clutch was and art form in itself to learn and soooooooo much smoother as you understood the relationship of the engine and transmission.
     
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  31. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

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    Years ago a friend calls me and says he's bought a bus that's been converted to a camper. I assumed he meant a school bus. Well this thing shows up in front of my house at 3AM. It's an old 50's era GM bus (the kind that looks like it's aerodynamically designed to run backward). The thing is dieseling away as the guy gets out and runs around to the engine and cuts off the air to stop the engine. Turns out he's practically burned up the brakes coming down because he doesn't know how to downshift. The next day I give him a quick lesson in double-clutch downshifts.
     
  32. Tantalum

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    Yes! This was a favorite party trick of mine
     
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  33. wayne

    wayne Pattern Altitude

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    The drag from downshifting comes from the engine. The clutch plate shouldn't be slipping that much. If it does you'll have trouble accelerating much too.

    I've had one car with an automatic as they didn't make a manual for it. Drives me nuts when my wife doesn't downshift with a manual; she was driving a Honda with a manual when I met her. Might as well use a "sissy-stick". :p ;)
     
  34. Tantalum

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    I had a mini I downshifted for 120K miles and never had a problem with the clutch. The clutch should slip very minimally. The deceleration comes from the compression in the engine
     
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  35. Juliet Hotel

    Juliet Hotel Pattern Altitude

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    So if you go from 55mph zone to a 35mph zone you come to stop first? :confused2::confused2::confused2:
     
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  36. flyingbrit

    flyingbrit Pre-takeoff checklist

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    I said turns not stops. Suppose you are coming up to a right turn and the light is green. I will down shift into second before making the turn. Do you leave it in top gear?
     
  37. steingar

    steingar Taxi to Parking

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    Actually, no you didn't. But for turns the procedure is the same. Downshift out of gear into first if I stop the bike, second if not, and third if I'm really having fun. I'm usually in the gear I want before I hit the turn so I can accelerate out of it. But what do I know, I've only been riding bikes for 35 years.
     
  38. Sac Arrow

    Sac Arrow Touchdown! Greaser!

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    Bro do you even lift
    The only time you're wearing the clutch significantly is when you are starting out in first gear. Constant mesh motorcycle transmissions don't even need to be shifted with the clutch, if you know what you're doing. Well, that goes for large truck transmissions too I guess.
     
  39. genna

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    In a modernish(anything with synchro-mesh transmission ) street car, on the street, I can't think of a good reason to double-clutch. Maybe it will extend the life of your synchros/transmission from 250Kmi to 300Kmi(made up numbers). Maybe. In reality, you won't even know if you are doing it correctly as synchros will mask any mistakes. It certainly not going to have any affect on your clutch's life(actually may shorten it somewhat as you are making more "slipping" moves). It's far more likely that you will will get rid of the car well before any conceivable benefit from it. Of course some cars have weak synchros, but that's a different problem.

    Also, downshifting to slow down is not going to do anything to your clutch if you are remotely competent with it(rev-match, quick release). Clutch has exactly the same role in engine braking as it does in acceleration. None, there is no movement! Unless it is used up and slipping or you are dumb enough to slip it.

    Now, race cars, semis, old cars, etc. are different types of animals.
     
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  40. SoonerAviator

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    I could imagine you would accelerate wear on the throw-out bearing/clutch fork if you are double-clutching all of the time on a modern syncho-mesh transmission. It's just unnecessary versus just rev-matching for downshifts.
     
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