clutchless DOWNshifting

[Paul_E_D]

I think it's just preference. I prefer less engine breaking. Leaned over downshifts smooth as butter allows later braking/higher entry speeds.

[Paul_E_D]

Thanks I'm not sure if any of us have clicked 16's yet THIS year but I'm thinkin we'll all be ticking some off at the classic. Pretty sure 14's are straight up outta reach for an SV... Even for Ricky.


... back to your scheduled programming.

I'm serious when I say that having a slipper will make it easier to run 16s every time you roll at Loudon. That would be a good goal. Better than a 14 or even 15s IMO. It will win you races.

[xsiliconkid]

I know this isn't a thread about slipper clutches per-se, but they're coming up enough that I had a quick question that may or may not warrant a separate thread:

but if we have an adjustable one, is there a rule of thumb where more or less braking preferable for the track, or is it purely a matter of personal preference?

I could see an advantage to either way, or even the possibility of preferring more engine braking on some tracks and less in others.

Thoughts?

just bang the downshifts wherever you do them without worrying about blipping the throttle or easing out the clutch.

[OreoGaborio]

I'm serious when I say that having a slipper will make it easier to run 16s every time you roll at Loudon. That would be a good goal. Better than a 14 or even 15s IMO. It will win you races.

Yeah I've had some thoughts about buying one, but $$$ is the restraining factor. I dumped enough cash into the chassis this winter that I don't have any fun money left to play with....... and if I did, I'd probably spend it on making my bike not look like crap so I could make it look like crap again later

[xxaarraa]

Yeah I've had some thoughts about buying one, but $$$ is the restraining factor. ...

Don't most bikes these days come with one? My last 3 bikes have. Isn't it the way of the world these days? Like traction control for superbikes, electric power steering and AWD for performance cars, HID lights for everything, etc. World has moved past non-slipper clutches it seems like.

[xxaarraa]

I think it's just preference. I prefer less engine breaking. Leaned over downshifts smooth as butter allows later braking/higher entry speeds.

Agree on preference. I suppose it also depends on what motor. On a V-twin, downshifting early and using the aggressive engine braking in leiu of hard braking for any particular corner, for instance, is a choice I have heard people make. I have never ridden an I-4, but I am told they don't have much engine braking at all? Same as 2 strokes?

The slippers generally come with adjustable springs of different ratings, so Ductard, you can "tune" them to your preference and based on track too.

[Paul_E_D]

SVs haven't moved past anything! lol.

It's true that most new bikes have some slipper clutch tech. But the stock stuff is not the same as what we use for racing. Stock, they use fueling tricks to make the bike less prone to chattering on downshifts. There is generally still a lot of engine braking.

The aftermarket clutches are ball and ramp style and the "release" a lot more than the stock types. The difference in feel is night and day! STM or Yoyodyne clutches are things of wonder. A lot less engine braking to allow aggressive and late downshifts that are butter smooth.

[jwm2k3]

Ducati 1299S. Clutchless up AND downshifting...I want one.

[xxaarraa]

Ducati 1299S. Clutchless up AND downshifting...I want one.

Wait 3 years. That's how long it takes Antonio to figure out how to make it right and iron out quirks. lol

[PhilB]

I ride mainly street; not much track (although I have done a few trackdays). I almost always use the clutch when shifting up or down, although it usually isn't a full squeeze; just a light squeeze to keep things smooth. I have practiced enough that I can shift well without using the clutch, both up and down, and that has come in handy a few times. For my bike, upshifting without the clutch is just preload the shift lever, snap the throttle closed for a moment to unload the gears and the shift happens, then throttle back on. Downshifting is even easier; just toe up the lever (I have reversed shift pattern on this bike), and the engine revs a bit between the gears and matches revs pretty well.

It has come in handy when:
Emergency acceleration is needed; it helps keep the drive going without interruption,
Carrying a load where being able to use my left hand to keep everything positioned properly is nice,
Riding for a couple hours in 30F weather and your left heated glove stops working,
There is some sort of failure in the clutch actuation system.

PhilB

[Marc R]

... I prefer less engine breaking...

Well, there is something we can all agree on, except my mechanic for the repair money.

[OreoGaborio]

I'm a huge engine breaking opponent.

Unless it's Ricky. Then I'm okay with it, even though he's a super nice guy.

[csmutty]

I see what you guys did there...

[Pittenger5]

I could bang downshifts on my RMZ450 like it farted rainbows, but on my CBR600 I can't even get the damn thing in gear.

[tsorfas]

MotoGP: Rossi, Lorenzo debut seamless downshifts | MotoGP 0

So it looks like up until RECENTLY even MotoGP riders used the clutch for downshifting and now use special gearboxes to do clutchless downshifts.

[Ductard]

MotoGP: Rossi, Lorenzo debut seamless downshifts | MotoGP 0

So it looks like up until RECENTLY even MotoGP riders used the clutch for downshifting and now use special gearboxes to do clutchless downshifts.

"MotoGP riders no longer need to use the clutch lever when downshifting, however this is unrelated to seamless technology."

Not sure what the change was, but that suggests that at one point they did need to use the clutch. Not sure if the "unrelated" change happened a year ago...20 years ago....

Either way, the whole idea of shifting by engaging 2 gears at the same time is crazy technology.

[sedanman]

My BMW touring bike has shift assist pro. It will do full throttle clutchless upshifts and closed ( or patiallly closed)throttle downshifts while it blips the throttle to match engine speed.

[tsorfas]

"MotoGP riders no longer need to use the clutch lever when downshifting, however this is unrelated to seamless technology."

Not sure what the change was, but that suggests that at one point they did need to use the clutch. Not sure if the "unrelated" change happened a year ago...20 years ago....

Either way, the whole idea of shifting by engaging 2 gears at the same time is crazy technology.

That's what the article really says.
That with the exception of Honda everyone else was using he clutch to downshift because it was upsetting the bike too much to do it clutchless.

[cdovego]

Sav, OTT has video of Mat Mladin talking about clutchless up/downshifts from over 10 years ago.

Right on the youtubes, google OTT and Mladin. 12 or 14 part series - great info.

[Kurlon]

That's what the article really says.
That with the exception of Honda everyone else was using he clutch to downshift because it was upsetting the bike too much to do it clutchless.

Not 100% accurate. Everyone else was having to put more thought into it, but I'd bet they were still doing it clutchless. Just like everyone does clutchless upshifts now on bikes that don't have fancy electronics or seamless gearboxes. Sure, on paper we "can't" do them, and yet we do. If I can pull off clutchless downshifts on a chinese clash box in a pitbike smoothly, I guaran-damn-tee the MotoGP kit could do them better even before seamless gearboxes came back in vogue. (What's old is new again, 60's Hodoka anyone?)

[grez]

Clutchless downshifting can take a fair amount of practice to get right on each and every shift, you can get a system from flatshifter in the uk that has a self regulating engine vacuum powered clutchless downshift system, a lot of good feedback on the system on the net.

[Kurlon]

Oh that setup ROCKS!

[GMAN226]

with a slipper I used the clutch in a few corners but I would bang a few without the clutch too.. But that was a tractor motor in an SS so who knows if that applies to real motorcycles