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Question about downshifting...

6506 Views 26 Replies 14 Participants Last post by  fitzy
Hey everyone.. So I 'acquired' a copy of the twist of the wrist DVD (which I might add is very good, bar the attrocious acting). Just a question though..

Towarda the end there was a 'scene' where they were downshifting.. And if I saw right, they would pull in the clutch and rev it while downshifting??? Did I see right??

He made a good point about engine breaking.. Pads are cheap, engines are expensive. I think from now on I'm just going to use brakes to slow me down, while pulling in the clutch and downshifting to an appropriate gear so that I have power when it is required to be put on..

Also, what does 'blipping' the throttle refer to?


Cheers
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you rev while downshifting to match the revs so make the gears mesh nicer from what I've been told
You're talking about is blipping the throttle...

A blip is when you bump up the revs to match the engine speed while down shifting. It's makes the engine breaking, and downshifting experience much smoother and won't cause you to lose it due to a massive change in engine speed while gearing down.

Clutch in - quick rev (on and off) and click down gear - while revs are still up release clutch.

The rear wheel is driving the engine at a certain speed during breaking. When you clutch in the engine goes to idle till you click into the next gear. Then the revs suddenly pick up due to the wheel engaging in gear again, but if the engine is running slower than the wheel it can cause the rear to slow down just a lil bit faster than it should be, causing it to lose traction...

Blipping avoids that as it trys to ensure that there is no change in load...

Of course I'm a stickless noob so thats just my basic understanding of whats going on and why you do it.
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blipping the throttle is what ninexz described, its the actual term for it.

its also to prevent rear wheel lock up.
Blipping is pulling in the clutch and revving it, and yes, that's what they were doing.

The engine is connected to the rear wheel by the clutch. There is no 'free play' in this system. Forgetting gears, lets say the engine needs to be spinning at 10,000RPM to do 100kph. When you pull the clutch in, you disconnect the engine from the rear wheel, breaking that relationship. So, if you're doing 100kph with the clutch in and the engine at idle, letting go of the clutch means the engine will need to get back up to 10,000 RPM, and it will be dragged back up to this by the rear wheel physically forcing it to. Making your rear wheel drag your engine up 9,000 RPM is a big ask, and it will typically lose traction and start skidding (slipper clutches prevent this), which is called a compression lock up.

So, back to blipping.

When you downshift, you're creating a difference between what the rear wheel is spinning at, and where the engine RPM's need to be. If you were doing 10,000 RPM in 3rd and kick to 2nd, the revs will have to jump up to ~14,000 RPM to maintain speed. When you pull in the clutch to kick 2nd, the revs instantly start dropping, compounding the problem further. To overcome this, we twist the throttle (blip it) to raise the engine RPM's up to (roughly) what they should be for the gear and speed you've selected. The closer you get it to perfect, the smoother the gear change.

Make sense?

Justin.
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The only real reason why anyone does it is because it makes you look like a sick karnt. Chicks dig it bro
Cheers for the explanations guys. I can see that it would be extremely helpful when you're going 250km/h and you need to downshift, as it would make it much smoother and you wouldn't get thrown off your bike, but is it practical on the street?

Should it be used in day-to-day travel?

Thanks again :D
I'm learning to back in the 250.. and ritually and habitually abuse the slipper on my R6 at broadford because with a dirt background I'm so used to relying on engine braking.

Blipping is to reduce the engine braking effect.
i think that avoiding compression lock is a good thing. it cant be good for the engine... blip away i reckon.
It should be used every single time you downshift, yes, making your ride smoother is always worth it and it's valuable practice for when you NEED to shift down in a hurry. After you get the hang of it it becomes automatic, you don't even realise you're doing it anymore.

Forgot to mention earlier, forget the advice about engines being expensive and brake pads cheap, there's absolutely nothing wrong with engine braking, it's only clutch braking that I would avoid (by blipping...).

Justin.[hr]
richo said:
Blipping is to reduce the engine braking effect.
To clarify my use of the made up term 'clutch braking'...

When you're cruising along in gear then let go of the throttle, the bike will start to slow down from a combination of wind resistance and engine braking. The higher the RPM the engine is doing when you let go of the throttle, the more pronounced the effect. This kind of engine braking is fine, it's a much more reasonable way to wash off 5kph than jumping for the brakes. This is frequently applied by shifting down early before a corner to lift the RPM (blip to match revs), and then allow it to slow you down WITH THE CLUTCH OUT.

What you shouldn't do is induce engine braking by pulling the clutch and letting the revs die then letting the clutch out to make the bike brake - 'clutch braking'. So, using the engine to slow down is fine, using the clutch to slow down isn't.

Justin.
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G
When you upgrade to something with a slipper clutch, blipping is a thing of the past. If you are riding your MC22, Blip away.
Chukitova said:
When you upgrade to something with a slipper clutch, blipping is a thing of the past. If you are riding your MC22, Blip away.
Erm.. if you like replacing clutches it's a thing of the past. I get a bit slack on the 6 sometimes when I go fishing for engine braking.. on the road I always blip.
I blip every time I ride... It makes it much smoother and easier to ride when you blip - so it's very practical for road riding!
G
richo said:
Chukitova said:
When you upgrade to something with a slipper clutch, blipping is a thing of the past. If you are riding your MC22, Blip away.
Erm.. if you like replacing clutches it's a thing of the past. I get a bit slack on the 6 sometimes when I go fishing for engine braking.. on the road I always blip.
Yes. I mean no. I disagree. How many clutches have you had to replace from not blipping? I havent had to replace any yet.

Not prematurely at any rate.

Blipping is a habit though. Hard to break. But not needed with a slipper clutch. That was essentially my point. Is fun to mash down through the gears and feel it do it's magic isn't it!
Chukitova said:
richo said:
Chukitova said:
When you upgrade to something with a slipper clutch, blipping is a thing of the past. If you are riding your MC22, Blip away.
Erm.. if you like replacing clutches it's a thing of the past. I get a bit slack on the 6 sometimes when I go fishing for engine braking.. on the road I always blip.
Yes. I mean no. I disagree. How many clutches have you had to replace from not blipping? I havent had to replace any yet.

Not prematurely at any rate.

Blipping is a habit though. Hard to break. But not needed with a slipper clutch. That was essentially my point. Is fun to mash down through the gears and feel it do it's magic isn't it!
I get a certain satisfaction out of hearing the thing wizz up for sure. I haven't blown up a clutch on the 6 yet (however it's not looking happy either). Even if I had blown one though there'd be no way to prove that the damage would have been done by not blipping anyway, so we'll never know before.

I can't imagine that all that slipping does the clutch any good. When you consider how much the clutch gets used in a normal ride (ie, very rarely, you take off rarely, you agressively take off VERY rarely) and the fact that it's repeated harsh abuse at high temps that destroys clutches, I can't imagine that deliberately not blipping is doing it any good.

Anyway that's just my 2c.
Even if slipper clutches don't 'wear out' (never looked into the mechanism they use to give slip, so I don't know but would assume they do), relying on them is similar to relying on an ABS unit or traction control, fine when you're piloting something that HAS one, not so good when you jump on something that doesn't.

Justin.
i blip most of the time... sometimes i do slip the clutch into engine braking. and hell, compression lock just looks cool on a motard
Accidently backing a brand new 600 into a corner at 130 kph may look cool to witnesses, but won't leave your undies looking very cool.

Trust me.

Justin.
you guys do know that if you do the entire blipping motion you all speak of but just ignore the clutch it works just the same right?

and before someone comes in saying "omg undue wear on dogs" after disassembling one of my MC22 motors after 60k km of clutchless upshifting and downshifting and riding it like a cheap whore, all dogs were in great nick. just dont be a tard and half shift and the undue wear wont happen...

/prepares for another clutchless shifting thread.......
mootavic said:
you guys do know that if you do the entire blipping motion you all speak of but just ignore the clutch it works just the same right?

and before someone comes in saying "omg undue wear on dogs" after disassembling one of my MC22 motors after 60k km of clutchless upshifting and downshifting and riding it like a cheap whore, all dogs were in great nick. just dont be a tard and half shift and the undue wear wont happen...

/prepares for another clutchless shifting thread.......
I do all my shifts clutchless at low revs on both bikes, however nearer to redline the difference in engine RPM that the crankshaft needs to go between on a downshift gets a shitton bigger.. if we're talking riding hard then I'm pretty sure clutching it is the done thing.

I have noticed that Rossi does it....
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