Quick shifter how does it work

One type assists on upshifts and the other assists on both upshifts and downshifts. Normally, on a motorcycle with no quickshifter, the rider closes the throttle. Then the rider actuates the clutch lever to decouple the drivetrain from the engine. Engine revs fall, and once there is no longer power flowing through the transmission, the gears within it are unloaded, permitting the shift dogs to release the gear combo being used. The rider then flicks the shifter to select the next gear, recouples the drivetrain to the engine by releasing the clutch lever, and finally reapplies the throttle.

To cut down the time, though, racers and street demons have long performed the clutchless upshift, which involves rolling off the throttle momentarily to unload the drivetrain, selecting the next gear, and then getting back on the gas. A quickshifter that assists on the upshift eliminates the needed motion of the throttle.

Normally this is done by cutting spark or fuel to the engine momentarily. On carbureted motorcycles, cutting fuel is not practical, so spark cut is the most practical method of interrupting engine power. This DynoJet quickshifter transducer senses both pressure and tension on the shift rod. DynoJet photo. The timing for the interruption is usually provided by a transducer mounted somewhere on the shifter or linkage.

Most common add-on setups run in-line with the shift rod. The transducer senses a change in pressure on the shifter or linkage, initiating the power interruption for the gear change.

Now, of course, the other half of the equation is the downshift. Not all quickshifters are capable of managing downshifts, because the process is a bit different. Despite having throttle cables, modern Yamahas are still ride-by-wire the potentiometer is operated by the cables, rather than being attached to the throttle tube , but if in doubt, call HM Quickshifter on , or email info hmquickshifter. For the first few miles I was disappointed — shifts were more positive feeling, but the gearbox still felt rather heavy and lumbering.

Pulling over, it was easy to lift the unit away from its mounting bracket and off the Velcro holding it in order to hold the button on the back while I turned the ignition on. From there I was able to cycle through selecting compression or extension operation for road or race orientation gearboxes , and into the sensitivity. With such easy changes, it became more noticeable that the kill time could be a little shorter — 50ms took the slight lurch out of the drive as the bike hesitated, ultimately bringing on a real improvement to the feel of the bike and giving gear changes that were even more enjoyable and less fatiguing on my foot.

Because the standard shifter is wired normally-open, there was no error code on the bike with it removed if there had been, it could have been zip-tied out of the way, or an eliminator plugged into the loom.

Motorcycle quickshifters: Are they safe, how do they work? By John Milbank. What does a motorcycle quickshifter do? How does it work? This is the standard quickshifter fitted to the Yamaha MT and Niken. What are floating dogs?! Every circuit is meticulously checked under a microscope before assembly. Are quickshifters just for race bikes? Why do some quickshifters feel better than others? Does a quickshifter damage a gearbox? What's the best quickshifter? The two-part compound must be applied in just the right way, in order to fully seal the electronics without fouling the button used in some units.

The factory-fit quickshifter on most current motorcycles uses a switch in-line with the rod that connects the gear-lever to the gearbox. A spring adds weight to that switch, but once compressed and contact is made or broken, depending on whether the switch is normally-open or normally-closed , the force being applied to the lever is transferred to moving the selector inside the gearbox, and the next gear ratio is selected.

Activation of the switch causes the spark plugs to be momentarily cut, ceasing drive. When the engine is driving the bike forward, the gears are being pushed by the crank. If you rolled off the throttle for long enough or cut the power to the spark plugs the bike would start to decelerate, and the momentum of the rear wheel would end up seeing it driving the crank through the gearbox, so acting in the opposite direction on the gears.

Watch the video below to understand it more…. In the same way that clutchless upshifts take advantage of float in the gearbox, to change down the engine speed required for the next lower gear needs to match that of the wheel speed.

A standard quick-shifter only works on up-shifts, whereas an auto-blipper allows you to change down gears. With an auto-blipper on a quick-shifter, if it goes wrong it could kill someone. While many prototypes have been toyed with over the years, Gareth has resisted putting an auto-blipper into production, despite many requests.

But after seeing some other products on the market, Gareth designed an aftermarket auto-blipper that has a default state that removes it from the throttle circuit. Put simply, unless a downshift is being carried out, the device is out of the circuit that controls the throttle position. Other systems can work by constantly reading what the rider is doing with the throttle, then passing that information on to the ECU, adding to it when needed.

Gareth is right to be obsessive about the quality of every solder joint on the quick-shifter parts. Image courtesy of Kawi Forums. Image courtesy of R6ers. In this case you have one cable for each sparkplug which suggests that this unit cuts the ignition when quick-shifting.

Whereas an unskilled driver manually operating the clutch is more likely to make the mistake of leaving the throttle open during up-shifting. The first answer is good and rather complete, and I would have added this as a comment if I had the reputation It might help to understand how a motorcycle gearbox differs from the traditional design that you will see in most explanations. The gears in a motorcycle gearbox do not slide on the shafts to engage and disengage gears, the gears are constantly engaged with each other but at least one of each pair is free to rotate on its shaft.

The gearchange mechanism moves dog-clutches around to alter which gears are locked to the input and output shafts. The dog clutches slide on splines on the shafts. The sequence in which the dog clutches slide is controlled by a cam drum connected to the shift lever. This means that it is possible to do very fast gearchanges on a motorcycle without using the clutch. All you need to do is unload the gearbox so that the dog-clutches are free to slide on their splines while moving the gear change lever.

Because of the sequential cam mechanism only a very small and fast movement of the lever is needed. Many motorcyclists myself included hardly ever use the clutch for up-changes. You just need to apply a gentle pressure to the lever, momentarily close the throttle, and the gearbox shifts smoothly and very quickly into the next gear.

Down-changes are more difficult to do smoothly, as you are typically loading the gearbox backwards and braking at the same time.

You need to press on the lever and momentarily open the throttle. This needs a certain dexterity to operate the throttle and brake at the same time. So, all that a quick-shifter does is measure the force on the shift lever and turn off the spark plugs when the lever is operated. This only works on up-changes, but cutting the spark rather than closing the throttle means that there is less disturbance to the air-path and the power comes back faster.

I you are worried that clutchless changes are bad, then you might be reassured to know that my Yamaha R1 has done , miles with very little motorway use with me shifting that way, and is still on the original gearbox and clutch.

An interesting development in MotoGP is seamless gearboxes.