Blip On Downshift

[nzbiker]

I am in two minds - is it necessary to blip on downshifts on bikes with a slipper clutch? any views on this?

[JeF4y]

It depends on whose minds you're in

 

I say YES. I've raced with and without slipper clutches on many bikes and have blipped and not-blipped. Ultimately I found that blipping made everything absolutely smooth.

 

Remember, you can and will slide with a slipper clutch. It just won't hop like without. If you blip, your odds of inducing a slide are significantly reduced.

[michael engel]

how do you blip and brake at the same time? in my car i just heel-toe it, but on my bike i find it difficult to blip the throttle and pulll in the brake.

[racer]

Use two fingers on the front brake and let the fingers slide across the lever while maintaining even pressure as you blip.

[Cobie Fair]

Use two fingers on the front brake and let the fingers slide across the lever while maintaining even pressure as you blip.

 

That's pretty much how we train it. One thing that can help, let the rpms come down a bit, then one doesn't have to blip as high. Also (and this is preference) I like zero throttle cable play to facilitate this.

 

Cobie

[michael engel]

i already use the two finger method, but it is difficult to maintain consistent pressure while blipping. i usually end up pulling the brake tighter when i rev

causing a jerking motion or i dont brake enough and end up having to lightly trailbrake through the turn to finish killing speed.

[racer]

Hi Michael,

 

It does take practice. The trick is letting your finger(s) SLIDE or SLIP back and forth over the lever while maintaining even pressure on the brake lever while blipping. It helps to leave room to slide back and forth, ie not using the tip of your finger(s) on the brake lever, but, rather starting between the first two knuckles. If you are having difficulty with that, you might consider adjusting your brake lever position. You can practice this technique standing still with the motor off, just experimenting with the motions of blipping and slipping together without jerking.

 

I had some difficulty when I first started learning this technique due to my square hands and short fingers making it difficult to operate the throttle when I was squeezing the brake. To overcome this, I began by using just one (my middle) finger (which I later noticed another very famous, short guy like me did as well). Later I was able to adapt to using two fingers.

 

Racer

[michael engel]

thanks! ive noticed that when i over-focus on it, instead of letting it happen naturally, my shifts are rough and uneven. ill try relaxing and loosing up my lever.

[Woody]

Also try doing as Cobie suggests and reduce the play on your throttle cable, it helps enormously.

[harnois]

I suggest learning to blip the throttle on downshifts without using the front brake first. Then once comfortable with that, and able to do that smoothly and consistently, then add the front brake into the mix. One step at a time.

 

I also adjust the throttle cable freeplay to almost zero. When the bikes come from the shop they almost always have huge amounts of slop in them. But I wouldn't go quite to zero, leave just a couple mm of freeplay. Turn the handlebars all the way both ways while the engine is idling. If the engine revs change, you need more slack in the cables.

 

In regards to shifting at lower rpms to make it easier, it might be worth noting that on some newer bikes they are doing some rather strange things that affect throttle sensitivity that might make this more difficult. I got a new 2006 GSX-R600 recently and have always had a hard time with this particular bike with shifting smoothly (up or down) when riding gently at lower rpms, like when riding on public roads. When riding aggressively on the track no problems with shifting. So I did some googling and read that the bike has a "timing retarder" which reduces the throttle sensitivity in the first 4 gears and in the first half turn of throttle. The timing retarder might not allow the engine to rev up quickly enough, and the amount of blip necessary and timing of the blip could change depending on which gear you are in. It's quite annoying actually. Downshifting and blipping at high rpms seems to work fine, but at low rpms it seems almost impossible to do it consistently smooth.

[racer]

Hey harnois,

 

Can you post a link to that info you found about a "timing retarder" for the first half of the throttle in the first four gears?

 

It sounds *very* counter-intuitive and is exactly opposite to the way I (and everyone I know) program ignition timing maps for a performance machine.

 

In any case, that's BOGUS, dude! The first thing I would do is get rid of it!

 

(The retarder thing, not the bike...lol.)

 

 

Thanks,

racer

[racer]

Also...

 

Low rpm blip/shift technique requires more blip due to less crank momentum prior to acceleration.

 

The same is true in the lower gear sets due to the greater difference in rpm between each gear as opposed to the closer ratios of the upper gear sets.

 

Low rpm blip/shifts in low gears is a slightly slower overall affair that can feel somewhat like "waiting" (especially with a slow, high mass stock crankshaft/flywheel) and may take a bit more practice to master the slower "feel" or timing of than high rpm blip/shifts in high gear.

 

 

Cheers,

 

racer

[michael engel]

i dont know if it is a retarder, but my zx6 needs a little clutch at moderate speeds when shifting. At "fun" speeds it shifts seemlessly with a minor blip, but at low speeds no blip is necessary unless im going into first.

[harnois]

Hey harnois,

 

Can you post a link to that info you found about a "timing retarder" for the first half of the throttle in the first four gears?

 

It sounds *very* counter-intuitive and is exactly opposite to the way I (and everyone I know) program ignition timing maps for a performance machine.

 

In any case, that's BOGUS, dude! The first thing I would do is get rid of it!

 

(The retarder thing, not the bike...lol.)

 

 

Thanks,

racer

 

Here's the link:

http://ivansperformanceproducts.com/tre.htm

 

I think what the manufacturers are trying to do with this sort of thing is dumb down the controls. Yes it is high perforamance machine, but the majority of people who buy it are not exactly high performance riders. To have such a light and high powered machine with a such a sensitive throttle could be a problem for beginners, so they make the throttle less sensitive in lower gears. Beginners should not buy this kind of bike in the first place but we all know that they often do.

 

For the riders who actually buy the high performance machine to do high performance track riding, yes, BOGUS is pretty much it. The effect of this throttle desensitizer is blatantly obvious when turning and simultaneously pulling away in 1st gear, like when pulling out onto a highway. There's this weird dead feeling and you have to open the throttle way more than one would expect.

 

The same bike also has other evidence of dumbed down controls. The amount you have to turn the throttle to get to full open is just rediculous. It forces you to consciously reposition the hand on the throttle to get it to full open. This I had to fix by adding material to the throttle sleeve where the cables wrap around it. There are aftermarker throttle sleeves to deal with this problem too. The other thing is the rear brake pedal requires a lot of pressure to get just a little bit of braking. Not sure how they accomplished that but this I actually like, because it gives more feel and in the rare event that I actually want to use the rear brake I only want to use it lightly anyway.

[racer]

Thanks for that, harnois.

 

I haven't worked within the industry for awhile, so there are many things I am not "up to date" on.

 

The last thing that pissed me off was the Hayabusa bhp limiter and HRC wide-squish/unlead RS heads. (Gives you an idea how long I've been away...lol.)

 

Anyway, a friend of mine owns a local Suzuki dealership and operates a national discount mail order OEM/aftermarket parts business as well. He probably knows about the TRE stuff already, but, I'll bet he'll be glad to find out if he doesn't!

 

Cheers,

racer

[racer]

i dont know if it is a retarder, but my zx6 needs a little clutch at moderate speeds when shifting. At "fun" speeds it shifts seemlessly with a minor blip, but at low speeds no blip is necessary unless im going into first.

 

 

Hey Michael,

 

I'm not familiar with late-model ZX6 tech spec's, but, "moderate road speeds" around town will generally find one in the "torque band", the lower half of the rpm range above "low end" but below the mid-range flat spot at the torque/bhp cross-over point (check out a graph of torque/bhp vs rpm from a dyno run) where the ratio of torque/rpm is greater, hence, it can be more dificult to access the "sweet spot" between positive and negative torque on the drivetrain to make your shift. In that 'torque band' a small on/off movement of the throttle makes a fast/big torque effect compared to a relatively low torque event for an on/off movement at high or very low rpm.

 

The point is that it is not an insurmountable goal with practice.

 

That said, like harnois' bogus retarded Suzuki, there may be some detail of your ZX6 that I am not aware of (and would never think of!) that might make it more difficult.

 

 

racer

 

 

PS: It's really helpful to separate road speed, engine speed and throttle position when thinking about "this stuff".

[Cobie Fair]

Interesting about the retrarder on the Suzuki.

 

We have no problem shifting the '07 (or earlier) 6R's at any speed, up or down w/out the clutch.

 

CF