On the street a false neutral is, usually, just a rare inconvenience. On the racetrack, at any kind of speed, they tend to cause riders a lot of consternation. They don’t just happen to the newbie. I’ve been riding and racing bikes for nearly 6 decades and occasionally I still hang a false neutral myself.
I have even heard experienced racers talk about the crash they had because of a false neutral. So, the questions about false neutrals are,
What Causes Them
If a rider knows what causes of the missed shift then, he can easily figure out how to avoid them in the first place.
Blipping the throttle
If blipping the throttle is not an important step in the downshift procedure then why has several manufactures gone through the expense of design, retooling, testing, and manufacturing of an “Auto Blip system”? Corporations don’t waste time and money on unnecessary stuff.
The reason to blip the throttle is to put some inertia in the crank shaft and to get the engine spinning fast enough for the lower gear. The problem of just letting the engine idle during a down shift at racing speed is there is too much difference in the speeds between the input counter shaft gears and the output counter shaft gears. This speed difference causes the gears to just grind against each other and fail to engage properly.
There are a couple of other benefits to blipping besides avoiding false neutrals but, that’s for another article.
Trying to Down Shift at Too High of a Speed
This often happens when the rider is nervous about getting all of his downshifts done in time, so he tends to rush the process. When the bike is still traveling at a high speed and the engine is still near or at its red line, then in order for the gears to match speed, the engine would have to be spun up to above red line. Unfortunately, in most cases, the rev limiter won’t allow that.
The result is the two sets of gears cannot match speed and fail to engage. Even if the gears do engage, the bike will become unstable, or the rear wheel starts to hope and skip around as the clutch is released. Only down shift when the revs get near the bottom if the power band. The only reason to down shift is to keep the engine in its powerband.
Besides missed down shifts, engine braking in and of itself has several other reasons to avoid it, those are covered, in more detail, in the accompanying article "Engine Braking". We will just look at it as it pertains to false neutrals here.
The use of the transmission to induce engine braking puts an awful high stress the transmission that it is not designed for. This can and often causes undue wear and tear on the entire drive train especially the gear box and shift forks. This will then often lead to the transmission not shifting properly and/or start to miss shifts.
Multiple Down Shifts All at Once
This is a bad habit that riders can “Get Away With”. Just because you can get away with it doesn’t mean it’s the correct way to shift. The main problem is the same as down shifting at too high of a speed. The first click down may be "OK" but, the second and third can result in the high speed difference as mentioned above.
The other problem with more than one click down without releasing the clutch each time is the “Unknown Factor”. The rider has no way of knowing for sure what gear he will be in when he releases the clutch lever. Did he get all three down shifts or was there a false neutral in the mix somewhere? He will be guessing and hoping he’s in the right gear. The biggest unknown factor is when the rider releases the clutch and finds he’s in a false neutral. What gear is he in-between? Did he get one two or three false neutrals during the process?
Why Do Riders Crash from A False Neutral?
The most common reason riders get into trouble from a false neutral is from the use of “Engine Braking” as a major feature of their braking sequence. They are relying on the engine compression to do a lot of the deceleration. That also means the rider is not using the brakes aggressively or efficiently.
Now when the rider hangs a false neutral the bike is no longer slowing down as fast as the rider wishes. He will now arrive at his normal turning point 5,10 or even 15 MPH faster than he has ever been there before, leading to a panic feeling of loss of control. He is also at his turning point 5, 10 or 15 MPH faster than he WANTS to be there, also inducing the panic. This panic will cause the rider to do one or both of the wrong actions.
First, the rider will grab a whole handful of front brake. Because he wasn’t using the brakes aggressively before now, the front tire will not be up to optimal temperature. This sudden aggressive braking can and often does, easily lock up the cold front tire. The other thing the rider may also do, from panic, is straighten the bike up and runoff the end of the straight, into the grass, feet down and at a very high speed. I've even seen a rider hang a false neutral, panic, lose control and run off the left side of the straight, then crash, while setting up for a right hand turn.
Avoiding False Neutrals in The First Place
What to Do When You Hang a False Neutral
How to Avoid the Panic of a False Neutral