Clutchless upshifting is one of the easier techniques you can employ on a motorcycle to enable smoother bike control and faster acceleration. If done correctly (and after a small amount of practice, you will), clutchless upshifting will not damage the gearbox – some even argue it reduces wear and tear.
To understand why clutchless shifting works, it’s beneficial to have a crash course on the insides of a motorcycle gearbox. Motorcycle gearboxes generally have a shift drum and shift forks with six different detent (a catch or lever that locks the movement of one part of a mechanism) positions in which the shift drum can reside. On almost all modern bikes, those positions are 1st, Neutral, 2nd, 3rd, 4th, 5th and 6th. When shifting from say 3rd to 4th, 3rd gear is disengaged before 4th is engaged – in that period between those two gears, your gearbox is not in any gear. This isn’t true neutral, in effect it’s a ‘no man’s land’ and this differs from a standard manual car gearbox, where you shift through neutral between each and every gear.
To switch between gears then, the drive train must be unloaded, allowing the decoupling and re-coupling to occur. One way to do this is to pull the clutch lever. But the way we want to do it is without the use of the clutch lever. We do this by blipping, or quickly rolling off and then on the throttle. The procedure is this:
1. Put upwards pressure on the gear selector with your foot.
2. Blip the throttle. You don’t need to completely roll off the throttle, but enough to see the engine rotation speed dip for a fraction of a second and then roll back on the throttle.
3. If done correctly, your upwards pressure on the gear lever will engage the next gear.
4. Take pressure off the gear lever until ready to upshift again.
You’ll find that after not too long you’ll have mastered this technique. See this video for a demonstration of how to shift without the clutch:
But what are the benefits of clutchless upshifts?
Firstly, it’s faster than using the clutch lever. Not engaging the clutch lever (which unloads the drive train for as long as you want) means you can upshift faster. More importantly, you’ll lose less engine speed as well. Depending on the gearbox and rider ability, a clutchless upshift may reduce engine speed by around 500rpm, whereas conventionally shifting with the clutch lever may reduce engine speed by 1000rpm. While not a massive difference, over the course of a race, the fractions of a second saved will accumulate.
Another benefit at the track is that not pulling in the clutch lever is just one less thing you need to worry about when riding at your limit. If you’re hanging off the bike on a right hand turn, its much easier to just blip the throttle and upshift, instead of having your left hand in the correct position to engage the clutch, especially when you want to minimize input into the bars. Not engaging the clutch for upshifts just means you have one less piece of motorcycle control that you need to worry about.