Rev match sequence?

[Trials]

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Your clutch has no idea or care what caused your engine to be at way lower revs then your transmission, it's a simple device that releases the clutch when you theoretically should have. Is like ABS for people who don't know how to engine brake. lol if lots of people totally rely on it for clutch control like some rely on ABS to compensate for poor brake control, ya lots of people are eventually going to need it.

"How do you rev match on a downshift without blipping the throttle?"
Pretty darn good! I bet on average I shift gears on my truck more smoothly then most people can drive their auto shift.
With the clutch btw, I don't make a habit of clutches shifting, don't paint me with that brush.

... What part of that device pushes the clutch plates tighter together under load? <- none, it's a one way only device.

 

[J_F]

street rider with a slipper clutch on a mall bike doesn't need to worry about this
but not a bad skill to have an understanding of, if thinking of moving to bigger bike

a larger displacement high compression engine and no slipper clutch
you'd want to know how to rev match to avoid locking the rear tire

When changing to a lower gear mid corner, smooth is an absolute must. Rev match...

^ 1,000 % this

someone is sure to say (because GTAM) just be in the right gear before you turn
but everyday I'm riding something causes me to drop a cog while leaned
when it feels squirrelly you sure wanna learn about this rev match thingy

 

[r3r3r3]

... What part of that device pushes the clutch plates tighter together under load? <- none, it's a one way only device.

Its basically just the slipper clutch working in reverse. When reverse torque (from the wheel) is sent through the clutch it activates ramps in the clutch reducing the spring pressure on the plates – allowing the clutch to slip. When the torque is going the “normal way”, engine to wheel, those same ramps are being forced into each other reducing the clutch slip / amount of spring pressure needed to keep the clutch from slipping.

Slipper Assist Clutches Are Appearing On More New Motorcycles

 

[bitzz]

A couple of points:
1) Modern motorcycle transmissions do not have "syncros". Motorcycles have sequential transmissions, not "sycro-mesh" transmissions. LARGE difference in this context. (If you didn't know that or you don't know the difference I suggest you stop commenting on transmission posts and go learn the difference...,)
2) There is no need to "blip" the thottle or "rev match" a close ratio sequential transmission that you find on modern motorcycles... if you have a clue on how to ride... like NOT shifting gears mid corner (shifting gears mid corner will ALWAYS upset the bike. Perfect shift or not, slipper clutch or not, changing gears mid corner is a dumb idea), or slamming it down a gear at redline. If you're riding something like a Norton, with a power band that goes from 2000RPM to 8000RPM, with a four speed REALLY wide ratio transmission, or you're racing an old two stroke, ya' might want to learn "rev matching", if you're riding a modern bike: ride like a sane person and you're golden.

 

[matt365]

A couple of points:
1) Modern motorcycle transmissions do not have "syncros". Motorcycles have sequential transmissions, not "sycro-mesh" transmissions. LARGE difference in this context. (If you didn't know that or you don't know the difference I suggest you stop commenting on transmission posts and go learn the difference...,)
2) There is no need to "blip" the thottle or "rev match" a close ratio sequential transmission that you find on modern motorcycles... if you have a clue on how to ride... like NOT shifting gears mid corner (shifting gears mid corner will ALWAYS upset the bike. Perfect shift or not, slipper clutch or not, changing gears mid corner is a dumb idea), or slamming it down a gear at redline. If you're riding something like a Norton, with a power band that goes from 2000RPM to 8000RPM, with a four speed REALLY wide ratio transmission, or you're racing an old two stroke, ya' might want to learn "rev matching", if you're riding a modern bike: ride like a sane person and you're golden.

#1 I will totally agree with.

#2 you are out to lunch...

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[bitzz]

Also floating gears in a synchomesh transmission is a bad idea. Much cheaper to replace a clutch than a worn out synchro. I have driven with a lot of self-proclaimed “clutchless experts” and unless you are hitting the exact perfect RPM on each shift you are causing excessive wear to your transmission. Don’t let your synchros fool you into thinking you are Ayrton Senna – its hiding your sloppy floats.

What is a "floating" gear?

You seem to think that a clutch is going to save your transmission from "bad shifts". NOT TRUE!
A "bad shift" is going to ruin your transmission, doesn't matter if the clutch is engaged or not. The clutch can dis-engage the forces from the engine, but the transmission still has the load/forces coming from the spinning rear wheel... which will take out the transmission.
Actually if you spin the trans at highway speeds, not connected to anything (no motor, no drive chain) there is enough energy in the transmission itself to do fatal damage.
Bad shifts are bad shifts, clutched or not.

 

[matt365]

O.P. has two choices.

One. - putter around never increasing your skillset. Ride for 20 years, but only have one years experience twenty times over.

Two. - learn. Read. Take courses. Get some help from knowledgeable friends and fellow riders. Take racer 5. Take FAST. total control arc 1&2. SMART rider training with Clinton Smout. Trail tours in the ganny. Expand your riding knowledge and ability.


What kind of rider do you want to be?

Anything you add to your bag of tricks is going to be beneficial. It should be constant learning for all of us.

My .02c

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[xrljoel]

A couple of points:
1) Modern motorcycle transmissions do not have "syncros". Motorcycles have sequential transmissions, not "sycro-mesh" transmissions. LARGE difference in this context. (If you didn't know that or you don't know the difference I suggest you stop commenting on transmission posts and go learn the difference...,)
2) There is no need to "blip" the thottle or "rev match" a close ratio sequential transmission that you find on modern motorcycles... if you have a clue on how to ride... like NOT shifting gears mid corner (shifting gears mid corner will ALWAYS upset the bike. Perfect shift or not, slipper clutch or not, changing gears mid corner is a dumb idea), or slamming it down a gear at redline. If you're riding something like a Norton, with a power band that goes from 2000RPM to 8000RPM, with a four speed REALLY wide ratio transmission, or you're racing an old two stroke, ya' might want to learn "rev matching", if you're riding a modern bike: ride like a sane person and you're golden.

Sadly, my Norton is missing this powerband you speak of. The 4 speed ratios are really wide though and require care and experience to maintain fluid forward motion. (Remembering that the shift lever is on the right side and has a reverse pattern helps too.)

And 8,000 rpm? The only way it hits 8,000 rpm is if it's dropped from a satellite and tumbles back to earth.

 

[jemlinus]

Nice to learn, but it will wear your clutch quickly if you constantly use the technique.

 

[matt365]

Nice to learn, but it will wear your clutch quickly if you constantly use the technique.

How's that?

There is no riding the clutch involved...

Rev match, release clutch.


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[jemlinus]

Yes, but still you need to use the clutch. More you use, you'll wear them out quicker.

For that reason, I upshift without using the clutch lever.

 

[matt365]

Yes, but still you need to use the clutch. More you use, you'll wear them out quicker.

So you don't use your clutch on a downshift?

Letting it out slowly on a downshift will wear it quicker than rev matching.

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[jemlinus]

So you don't use your clutch on a downshift?

Letting it out slowly on a downshift will wear it quicker than rev matching.

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Sometimes I don't but usually, do.

If you are slowing down from 6th gear to 2nd, you'll need to rev match 4 times. Instead, use the brake lever to slow down and use the clutch once it will save the clutch wear.

 

[matt365]

Then you rev match four times.
Its not hard. Its actually alot of fun when you get good at it; and it becomes second nature pretty fast. I'd also argue that its proper form to rev match.


My current bike has autoblip downshift, and a quickshifter. It has made me a bit lazy... I can disable the autoblip and do it manually.

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[Brian P]

None of the choices that the original poster made available are correct.

Pull in the clutch lever and simultaneously slightly open the throttle and simultaneously change gear, then let out the clutch. The first three things all happen together, and quickly. The correct amount to open the throttle depends on revs, and it comes with experience. It is not necessary to get the rev-matching 100% correct but closer means smoother.

A slipper clutch will cover up a bit of sloppiness, but even on bikes that have it, I don't rely on it. It will not stop the engine from over-revving if you do too many downshifts at too high road speed.

I just got back from Grand Bend. Long track race weekend. Yamaha R3, no slipper clutch. "Oh my Gawd" corner at the end of the long straight requires three downshifts, all rev-matched, the third one delayed until after the turn-in point to avoid over-revving, the engine braking slides the rear wheel while I'm turning in. My old FZR400 would not be happy with me doing that, but this bike is okay with it. Fun times.

 

[Trials]

A slipper clutch also gives you a much lighter clutch pull as the ramping design forces the clutch together while the engine is sending power to the wheel. As a result the clutch springs can be lighter. ...

What?

Its basically just the slipper clutch working in reverse. When reverse torque (from the wheel) is sent through the clutch it activates ramps in the clutch reducing the spring pressure on the plates – allowing the clutch to slip. When the torque is going the “normal way”, engine to wheel, those same ramps are being forced into each other reducing the clutch slip / amount of spring pressure needed to keep the clutch from slipping.

Slipper Assist Clutches Are Appearing On More New Motorcycles

"When the torque is going the “normal way”, engine to wheel, those same ramps are being forced into each other..."
No!
the ramps are doing nothing! They already re-engaged the drive, their job is done.

 

[bitzz]

I think he is confusing a slipper clutch with a lockup clutch.
A locker clutch has little cams that are counter-weighted, and these cams swing in at a preset RPM and lock the clutch on. A lot like a locking torque converter in an automatic auto transmission.
The only place I have ever seen them used is in drag ATVs and sleds.

 

[r3r3r3]

What?


"When the torque is going the “normal way”, engine to wheel, those same ramps are being forced into each other..."
No!
the ramps are doing nothing! They already re-engaged the drive, their job is done.

"
More recently engineers realized that a slipper could work both ways, reducing clutch spring pressure to solve the engine-braking problem yet also increasing spring pressure when under power (now called "assist") in proportion to engine torque. Here was a function every rider could appreciate because it allowed clutch spring pressure to be reduced, making it easier for the rider to pull and smoothly control the clutch. The more throttle the rider used, the more pressure the ramps applied to the clutch plates, preventing slippage."

+

Engine management - Kawasaki Technology

nearly every modern slipper clutch is a "slip and grip", "assist slipper", etc. I misspoke when I said the same ramps, it is a second set of ramps in the opposite orientation that force the clutch pack together.

 

[blackcamaro]

All three of those steps happen at the same time. You don't need to perfectly match the rpm's just get close and it will be much smoother then not rev matching.

Practice in higher gears first. It'll be a bit more forgiving.

Once you have just downshifting while rev matching dialed in then you can add the front brake to the mix as well.

 

[JFD]

@OP do you drive a MT car?

I'm not a bike pro but have owned manual cars for a while now. It's the same thing ...

Figure out what RPM the bike likes to go at 60 km/h, 100 km/h, 120 km/h then just downshift one gear... See where the rpm is and memorize it. Next time you downshift, you want to blip the throttle and let the clutch out so he bike "bites" within this range. As you get better add braking into the mix to slow down way faster.

example

100 km/h - gear 6 - hovers around 6000 rpm
100 km/h - gear 5 - hovers around 7000 rpm
100 km/h - gear 4 - hovers around 8000 rpm

So when you downshift, throttle off, blip the throttle a little past 7500 or even 8000, shift down and let the clutch out.. If you do it perfectly, the rpm will be ~7000 when the clutch is released...

For now, it is better to rev MORE than LESS.

I don't know a single rider that looks at their rpm to shift gears.

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