Quickshifter...rather weird discovery

[Skidood]

On my 2019, I noticed that the switch is actually part of the linkage rod that transmits the shift lever movement to the input shaft.  And when shifting up slowly, the rod will move up and rotate the input shaft BEFORE the switch actuates.  You have to pull up a bit harder on the lever after the input shaft rotates in order to actuate the switch.

So, on a shift up,  this means that the switch does not send the signal to the ECU until AFTER the input shaft has rotated.  Bizarre!  How can it properly cut power for the shift if the input shaft has already rotated by the time the switch actuates??

[tedski]

From experience with clutchless upshifts on all of my bikes (none have quickshifters), you learn that you can weight the shift lever and then decide when to blip the throttle to shift.  With the engine load on the gears, the shift fork can't move things until the throttle is blipped and that pressure is relieved.  This translates to the quickshifter mechanism so that the power cut is as near as the point of the shift fork being ready to move things.  Hope that helps explain it.

[Skidood]

27 minutes ago, tedski said:

From experience with clutchless upshifts on all of my bikes (none have quickshifters), you learn that you can weight the shift lever and then decide when to blip the throttle to shift.  With the engine load on the gears, the shift fork can't move things until the throttle is blipped and that pressure is relieved.  This translates to the quickshifter mechanism so that the power cut is as near as the point of the shift fork being ready to move things.  Hope that helps explain it.

Yes it did, thanks.  

[duckie]

1 hour ago, Skidood said:

On my 2019, I noticed that the switch is actually part of the linkage rod that transmits the shift lever movement to the input shaft.  And when shifting up slowly, the rod will move up and rotate the input shaft BEFORE the switch actuates.  You have to pull up a bit harder on the lever after the input shaft rotates in order to actuate the switch.

So, on a shift up,  this means that the switch does not send the signal to the ECU until AFTER the input shaft has rotated.  Bizarre!  How can it properly cut power for the shift if the input shaft has already rotated by the time the switch actuates??

Wrong thinking.....my guess is that the type of switch used is a pressure switch, which are very sensitive. Think digital food scale. 

It takes a certain amount of pressure to change gears. The pressure needed by the switch to send a signal is way less than the pressure to change gears. 

This is why when using the quick shifter the shift action needs to be smooth and complete and a full motion.

There is no need to preload the shifter.

Edited June 28, 2021 by duckie

[Skidood]

31 minutes ago, duckie said:

Wrong thinking.....my guess is that the type of switch used is a pressure switch, which are very sensitive. Think digital food scale. 

It takes a certain amount of pressure to change gears. The pressure needed by the switch to send a signal is way less than the pressure to change gears. 

This is why when using the quick shifter the shift action needs to be smooth and complete and a full motion.

There is no need to preload the shifter.

That's not outside the realm of possibilities...but I have worked with hundreds of different kinds of limit switches and pressure switches in my work, and do have to say I kind of doubt it works as you say  ....the switch input rod moves inwards into the switch  about 1/4" (and at that point is where I assume the contacts close) but the rod doesn't physically move inwards until after sufficient pressure has been applied to rotate the input shaft.  (just a static test in my garage, engine not running).   The only way to know for sure is use a meter on the switch terminals while moving the shift lever.  I may go out and do this tonight 

[duckie]

Well, you are wrong.....nuf said

[Skidood]

20 minutes ago, duckie said:

Well, you are wrong.....nuf said

Wait...first you say its a guess on your part and then you say I'm just wrong?  Got anything to back up your statement?  Did I say you were wrong??   I could tell you what I just discovered when I went to check it out in my garage just now but won't bother now.  Nicely done.

[tedski]

11 minutes ago, Skidood said:

Wait...first you say its a guess on your part and then you say I'm just wrong?  Got anything to back up your statement?  Did I say you were wrong??   I could tell you what I just discovered when I went to check it out in my garage just now but won't bother now.  Nicely done.

Hey, for the rest of us who actually want to have constructive conversation and learn from each other... please share your findings.

[skipperT]

That went south quickly... must be the heat. 

-S

[Skidood]

Tedski, that's what my intent was, and always is.  Unfortunately the test was somewhat inconclusive.  I couldn't access the connector, didn't want to start taking the bike apart to look for it, so I tried the procedure where you disable the QS by holding the switch in  and turning the power on ...wedged  a block of wood under the shift lever just enough to  push the switch rod inwards about 1 or 2 mm.  Takes a large amount of force to do this....Switch did not appear to have changed state (QS light stayed on)...then adjusted the block of wood to apply plenty of pressure to keep the switch rod fully depressed hard into the switch housing...QS light stayed on indicating switch still didn't change state..so until I can access the wiring from the switch and get my meter on them, no answers.  From an engineering point of view which includes fault detection,  (bad contacts or cut wire) I bet this switch is normally closed and the contacts open as soon as the rod has moved just a wee bit inwards.

Edited June 29, 2021 by Skidood
..

[Skidood]

I do think it works the way tedski  said...input shaft wont turn due to pressure on the gears, the switch changes state, power cut, input shaft rotates.

[tedski]

13 minutes ago, Skidood said:

Tedski, that's what my intent was, and always is.  Unfortunately the test was somewhat inconclusive.  I couldn't access the connector, didn't want to start taking the bike apart to look for it, so I tried the procedure where you disable the QS by holding the switch in  and turning the power on ...wedged  a block of wood under the shift lever just enough to  push the switch rod inwards about 1 or 2 mm.  Takes a large amount of force to do this....Switch did not appear to have changed state (QS light stayed on)...then adjusted the block of wood to apply plenty of pressure to keep the switch rod fully depressed hard into the switch housing...QS light stayed on indicating switch still didn't change state..so until I can access the wiring from the switch and get my meter on them, no answers.  From an engineering point of view which includes fault detection,  (bad contacts or cut wire) I bet this switch is normally closed and the contacts open as soon as the rod has moved just a wee bit inwards.

I couldn't find the QS switch on the wiring diagrams in the FSM.  I was hoping we could get the switch spec from there.  But, thinking through the installation process... the way you enable the QS is to also hold the shifter up, so that leads me to believe it's normally open.  My thinking is that when the connector is bare (bike without QS installed), the circuit is obviously open.  If it were a normally closed switch, then holding the shifter up (engaging the switch) would not be a different state from the absence of a QS.  

[PhotoAl]

I always thought the “switch” was actually a strain gauge rather than a physical switch but haven’t looked at mine that close.  Quick shifter or clutch less. Shifting work the same.  The shift leaver is loaded, I.e. pressure I put on it in an effort th change gears but sine the “dogs” are under load they won’t move.  When the throttle is turned back load is removed from the gears I.e. dogs, they can move and the shift is made.  What the QS does is since the preload pressure on the shift arm and quickly lowers the throttle then quickly restores it.  Same hung an experienced rider does when making a clutch less shift by very quickly rolling off the throttle then back on.

at the end of a 2week trip to Wyoming, Utah and a corner of Idaho.   Have identified some great mountain roads.  QSis great and works well and reliably when riding is a sporty mode.  Also works great when passing on a 2 lane road.

[Skidood]

12 minutes ago, tedski said:

My thinking is that when the connector is bare (bike without QS installed), the circuit is obviously open.  If it were a normally closed switch, then holding the shifter up (engaging the switch) would not be a different state from the absence of a QS.  

Yes.... on a normally closed switch, holding the shifter up will open the switch contacts...and with an open circuit on powerup, the ECU will deem this a fault and disable the QS, or assume no QS is installed.   

[Skidood]

15 minutes ago, PhotoAl said:

I always thought the “switch” was actually a strain gauge rather than a physical switch but haven’t looked at mine that close.  

Strain gauge (aka pressure sensor) would be overkill, a switch is really all that's needed, and the symbol for the switch that is shown on the electrical schematic in the other QS thread is the symbol for a switch.  A pressure sensor or strain gauge is a different symbol.