Downshifting smoothly, especially while braking hard, requires skill and dexterity. To avoid upsetting the bike, the engine rpm in the new gear must be matched to the road speed before the clutch is engaged, otherwise the rear tire will "chatter" momentarily and upset the bike as the engine rpm is forced to match road speed. To do this the rider must "blip" the throttle to raise the engine rpm during downshifts... but he must do this while simultaneously pulling on the front brake to slow down. While this riding skill is obviously necessary on the racetrack, it can also pay big dividends in street-riding situations where riding smoothly is a must; for instance, any situation where you are braking on a slippery surface.
The idea of blipping the throttle during downshifts can be intimidating initially, but with a little practice, the technique will soon become second nature.
First, make sure that your levers are adjusted as described in Chapter 1. Check that your throttle is adjusted for minimal play in the cable. With the engine running in neutral, try blipping the throttle slightly while pulling firmly on the brake lever. Note that it doesn't take much throttle movement to get the revs up with no load on the engine. Then practice simultaneously pulling and releasing the clutch quickly when you blip the throttle (remembering to continue pulling on the brake lever as if you were slowing for a turn). Some people only use two fingers on the brake lever, others all four. Don’t be afraid to experiment and find out what works for you.
Next practice this technique while riding in a safe area with no traffic hazards. As you brake and begin your downshift, simply use the same method as before, but add the act of downshifting. The action of blipping the throttle and the downshift should be simultaneous and quick. It doesn't take a whole lot of extra revs to match the engine to road speed, so all it will require is a slight throttle blip. With practice, you'll know just how much is necessary at various speeds. Note that mostly the palm of your hand and thumb that perform the act of moving the throttle. Your upper body weight is centered on your palms under braking anyway, and your fingers are busy actuating the brake and holding the bar. All it takes is a slight wrist movement to blip the throttle. You'll find this will help avoid affecting your braking action or steering.
If you find that you still have problems with this technique, try adjusting your brake so that your fingers are less stretched out (without hindering your ability to pull the lever in for maximum braking, of course).
If you continue to have trouble, you will have to employ the "non-blip" method even some racers such as Eric Bostrom use. This simply means the clutch is released gradually after the downshift so that the engine rpm can rise progressively to match road speed without the rear wheel chattering. The downside is that the rider must allow for some extra engine braking as the clutch is engaged, limiting if there is little load left on the rear tire as a result of weight transfer. Also, it requires even more skill at manipulating and controlling the bike while simultaneously releasing the clutch lever slowly and gradually.
UpshiftingAlthough it is the right way for beginners or novice riders, using the clutch for upshifts is totally unnecessary. In fact, there are many riding situations where it can be a nuisance and even a hindrance to quicker and smoother riding.
Beware!
It is possible that your bike may have some shift or transmission issues that prevent using this technique. If so, see what aftermarket accessories are available.
A motorcycle’s gearbox differs from your typical automobile manual transmission in that it can actually change gears under a small load, and only needs a slight interruption in the flow of power to accomplish an upshift. Its constantmesh, sequential dog-engagement design means it can change gears much more readily than a typical automobile synchromesh transmission. This is why "power shifters" are so popular with motorcycle racers; by using a device that cuts ignition momentarily while upshifting, the rider is able to keep the throttle pinned wide open, saving time and effort.
Basically, clutchless upshifting is simple: Instead of shutting off the throttle completely and pulling in the clutch while you shift, just let off the throttle some and perform the upshift in a quick, near-simultaneous movement; ignore the clutch. Don’t shut the throttle off completely, just let off enough to get the shift done. Upshifting without the clutch also gets you in the habit of performing the shift quickly and smoothly. This minimises the effect of weight transfer from letting off the throttle so as not to upset the bike’s handling. Once you become accustomed to using this technique, you’ll be amazed at the time and energy saved (and you’ll probably reduce wear and tear on your clutch plates, too).
There are riding situations where the physical exertion saved from not having to constantly squeeze the clutch lever during upshifts can be a huge benefit. For example, accelerating through a series of turns your arms and hands are busy steering the bike, so it’s quicker and smoother to do without the clutch.