Another DCT trans question

[the Ferret]

When you are in manual mode, using the paddle buttons, do you have to back off the throttle then hit the button, or do you just leave the throttle on and hit the buttons? or leave the power on and hit the upshift button, but back off the throttle for down shifts and hit the button?

 

[bigbird]

Leave the throttle on and use the paddles, up or down, just like a car with a DCT.
It's like speed shifting LOL.
It's a no brainer. You'll love it.

 

[the Ferret]

interesting. Thanks for the info bigbird (never driven a car with a DCT and never driven a car with paddle shifters)

On my morning ride on the CB I wondered how different it is going to be.

Wish it would get here already lol

 

[670cc]

The DCT doesn’t know how to rev match, but the gear ratios are so close together and the shifting is smooth and quick. You can just hold the throttle wherever and hit the shift buttons.

 

[hulkss]

The DCT's with throttle by wire (2021 NCs) probably have some throttle blip programmed in for shifting. The Goldwing does.

 

[670cc]

The DCT's with throttle by wire (2021 NCs) probably have some throttle blip programmed in for shifting. The Goldwing does.

The 2021 NC either will, or it won’t. I never assume anything about Honda motorcycle features.

 

[dduelin]

if the throttle isn’t closed when the downshift is manually performed the transmission doesn’t have to blip to rev match. The next lowest gear is already in mesh and spinning at the exact rpm needed but it’s clutch is disengaged. Punch the - button and the clutch engages and the downshift is seamlessly made.

 

[Janus]

A DCT trans question? Excuse me but did you just assume the bike's gender‽

 

[the Ferret]

it's a binary motorcycle. It isn't really sure what it is lol

 

[Janus]

The 'Enby'750X

Honda marketers if you are reading this, I have unlocked the secret to marketing to a subset of millenials. You can pay me by bringing the ST1300 back to America

 

[670cc]

if the throttle isn’t closed when the downshift is manually performed the transmission doesn’t have to blip to rev match. The next lowest gear is already in mesh and spinning at the exact rpm needed but it’s clutch is disengaged. Punch the - button and the clutch engages and the downshift is seamlessly made.

When the riders punches the up or down manual shift button, the shift occurs very quickly. In your post, you said the next lowest gear is already in mesh. If you are in, for example, 4th gear, the DCT does not know whether you are going to press the up or the down button. So to say the next lowest gear is already in mesh is to also say the next higher gear is already in mesh and spinning at the exact RPM needed, too?

Whichever way you shift, the gears may be in mesh but the engine speed is not yet at the RPM needed for next gear ratio and road speed. If there is no throttle management, the engine speed would match up to road speed upon completed full engagement if the newly engaged clutch. This would also be true of a single clutch manual shift transmission.

 

[hulkss]

if the throttle isn’t closed when the downshift is manually performed the transmission doesn’t have to blip to rev match. The next lowest gear is already in mesh and spinning at the exact rpm needed but it’s clutch is disengaged. Punch the - button and the clutch engages and the downshift is seamlessly made.

Consider an example where the DCT bike is in fourth gear and you are going to down shift, third gear on the other clutch shaft is in mesh, shift dogs engaged, ready to transmit torque when the clutch engages. If the DCT instantly disengaged the fourth gear clutch and engaged the third gear clutch there would be an engine speed mismatch. The engine has to rev-up to match road speed in the lower gear.

With out the throttle blip feature of the Africa Twin and Gold Wing, the DCT uses the clutch to pull the engine up to speed during a down shift.

The transmission pre-selects the next gear when you push the upshift or downshift button, or the software makes the decision for you if in auto.

 

[TacomaJD]

The two DCT bikes that I have both work the same way in that you can't downshift unless the bike is below a certain speed or rpm, not sure which the computer uses to decide whether or not you can downshift, but I know my 2013 won't let me downshift into 3rd from 4th when I am on the track until I get down to 68mph. I'm usually going into turns continuously pressing the downshift button with nothing happening until it finally gears down to 3rd when I slow down to 68 mph. There isn't enough difference in the rpms between gears given the parameters that have to be met for a downshift to occur, so there's no need for throttle blipping / rev matching, etc.

Here's ya some full throttle upshifting, and downshifting as early as possible, footage.

 

[Deleted member 1183]

Also when using manual only the bike will either upshift or downshift automatically if one exceeds the high or low rev limit programmed into it for any one gear. On the only occasion I used manual only I discovered this.

 

[bigbird]

Also when using manual only the bike will either upshift or downshift automatically if one exceeds the high or low rev limit programmed into it for any one gear. On the only occasion I used manual only I discovered this.

My '20 will not upshift automatically if in manual mode.
The owner's manual specifically tells the rider not to over-rev the engine in manual mode.

 

[670cc]

Consider an example where the DCT bike is in fourth gear and you are going to down shift, third gear on the other clutch shaft is in mesh, shift dogs engaged, ready to transmit torque when the clutch engages. If the DCT instantly disengaged the fourth gear clutch and engaged the third gear clutch there would be an engine speed mismatch. The engine has to rev-up to match road speed in the lower gear.

With out the throttle blip feature of the Africa Twin and Gold Wing, the DCT uses the clutch to pull the engine up to speed during a down shift.

The transmission pre-selects the next gear when you push the upshift or downshift button, or the software makes the decision for you if in auto.

If there is only one shift drum, how can the fourth gear dogs be engaged and transmitting power, and the third gear dogs also be engaged. Does the shift drum have combined steps not found on a manual transmission shift drum, such as 3 and 4 together, then 4 along with 5, then 5 and 6? In other words, the shift drum slot pattern always has two sequential gear dogs engaged at any time? I had not thought about it that way before, but it makes sense.

That way if the rider were going to manually upshift or downshift from a mid ratio gear (2-5), there is a 50-50 chance on whether the shift drum has to move to shift, or stay where it is.

 

[lootzyan]

If there is only one shift drum, how can the fourth gear dogs be engaged and transmitting power, and the third gear dogs also be engaged. Does the shift drum have combined steps not found on a manual transmission shift drum, such as 3 and 4 together, then 4 along with 5, then 5 and 6? In other words, the shift drum slot pattern always has two sequential gear dogs engaged at any time? I had not thought about it that way before, but it makes sense.

That way if the rider were going to manually upshift or downshift from a mid ratio gear (2-5), there is a 50-50 chance on whether the shift drum has to move to shift, or stay where it is.

Maybe this may help you to further explain the difference between DCT and manual gear selection. There is some more information in the attachment.

 

[TacomaJD]

Also when using manual only the bike will either upshift or downshift automatically if one exceeds the high or low rev limit programmed into it for any one gear. On the only occasion I used manual only I discovered this.

This has not been my experience in either my 2013 or 2016 regarding upshifting. Now it will downshift if you slow to a stop and forget to downshift it yourself, but it does so at very low speed / rpm's. I've hit the rev limiter many times in many different gears riding like a hooligan in manual mode on both bikes and they will not upshift.....only way they upshift without my input is in either D or S auto mode.

 

[Deleted member 1183]

Ok. As I said above I only ever used the bike in manual once and that was my recollection. My (X-Adv) has 2017 tech. I will be riding it tomorrow and I will give it a try in manual once more if I think of it.

 

[Deleted member 1183]

When you are in manual mode, using the paddle buttons, do you have to back off the throttle then hit the button, or do you just leave the throttle on and hit the buttons? or leave the power on and hit the upshift button, but back off the throttle for down shifts and hit the button?

Look what You have started


Anyway I think Your question was answered in the second post.