Motorcycle quickshifters: Are they safe, how do they work?

Quickshifters have become commonplace on many motorcycles, and not just race bikes. Tourers, street bikes and even cruisers are all getting these devices, but they’re far from all the same; from the most basic systems to full auto-blippers, they can feel completely different. Not all quickshifters are created equal.

So how does a quickshifter work, how do they help you change gears on a motorbike and can it damage your gearbox? I visited HM Quickshifter in Sittingbourne, Kent to find out. Behind the door of this small industrial unit is a team of five that hand-builds the strain-gauge-equipped quickshifters found on the vast majority of race bikes around the world.

The company is led by Gareth Hopkins, who’s designed electronics since he was twelve, has a masters degree in mathematics and raced bikes in the late 1990s. Of the previous jobs he’s allowed to talk about, he designed the guidance math and electronics for an air-to-air missile; “That was really interesting as the speed of the thing meant that you only had the opportunity for one directional correction – if you tried to correct it again, the G-forces would pull it apart. It was really interesting predictive mathematics.” This is a guy who knows how to make complex electronic systems.

Gareth Hopkins is the boss of HM Quickshifter, working with a team of four that includes his wife, Zarra, and their son and successful racer, Luke Hopkins

Gareth also designed the world’s first GPS-based speed-camera detector (the Morpheus Geodesy), but it was when he teamed up with HM Racing that he developed a traction control system for supermotos, then went on to design quickshifters.

When HM Quickshifter got homologation for Moto2, the company saw its products going from being on just one machine on the grid, to being on every single bike except a factory HRC that had to use a factory shifter. “Despite that,” says Gareth, “We’re the only after-market product besides Renthal bars that are approved by HRC.

“Race teams started to understand the advantage of a strain gauge-based system, and the business really took off.”

All design, programming and development is carried out by Gareth

All of HM Quickshifter’s products (their shifters, pit boards and dash) are designed, prototyped and programmed in house, then the circuit boards are subcontracted out for component mounting. When they come back, they’re each tested, wired up and potted (sealed in a waterproof compound) back in the small unit in Kent. The aluminium parts are locally sourced, and the highly specialised task of laminating the strain gauge to the machined part that sits on the bike’s selector rod is also done by Gareth and the team.

“We’ve been making the Quickshifter Plus for more than ten years, and the failure rate is something like 0.01%. And most of those are the result of a crash or an installation problem,” says Gareth.

All of HM Quickshifter’s products are designed to be ‘plug and play’; “I’m of the school of thought that if you need a user guide, you’ve failed as a design engineer. We try really hard to make our products really easy to install and use.”

The potting is done entirely by hand in a temperature-controlled room at HM 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. Bubbles could also be an issue, so each device is meticulously sealed to ensure it’ll be as reliable on a race bike flat out in the rain as it will be on a road bike touring the Alps.

What does a motorcycle quickshifter do? How does it work?

The factory-fit quickshifter on most current motorcycles uses a switch in-line with the rod that connects the gear-lever to the gearbox. In the case of the most common – an upshifter – as the lever is pushed up (on a race box it’s pushed down), the switch is first compressed and contact made. 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.

It’s a simple design, but it relies on a positive shift being made by the rider, and it takes away the direct feel of a solid linkage rod, as you’re introducing a degree of sprung travel to the system.

This is the standard quickshifter fitted to the Yamaha MT-09 and Niken.

Activation of the switch causes the spark plugs to be momentarily cut, ceasing drive. It’s the same process (but faster) as briefly rolling off the throttle while you flick into the next gear.

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. Between those two moments – as the engine speed decreases and matches the speed of the gears when they’re driven by the rear wheel – the gearbox has a moment of ‘float’, where the dog teeth that engage the gears are between each other. Watch the video below to understand it more…

What are floating dogs?!

A rough-and-ready explanation of what’s happening inside your bike’s gearbox

What’s an auto-blipper quickshifter?

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. As you’re off the throttle, the rear wheel is driving the engine, so blipping the throttle increases the engine speed, and at the moment between the rear wheel driving the engine, and the engine driving the rear wheel, the gearbox will again float. You can do it by hand, but it’s a lot harder than a clutchless upshift.

What’s the risk of fitting an aftermarket auto-blipper?

A standard quick-shifter only works on up-shifts, whereas an auto-blipper allows you to change down gears. But while the former just requires the engine to be momentarily cut, a down-shifter needs throttle input – this means that any device will have to take control of your bike’s throttle – taking that control away from you, the rider.

I figured that being able to design an air-to-air missile guidance system was more critical than a motorcycle quick-shifter, which proves Gareth and the team’s ability to make reliable shifters, but he disagreed; “If a guided missile system goes wrong, failure means it’s not going to kill someone. 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. “I’ve designed electronics for all sorts of industries,” he tells me, “and they do go wrong. It’s a hell of a challenge to make something that really is fail-safe.”

OE quickshifters that come with a bike from the factory are integrated into the system, so if they fail, in theory the bike just shouldn’t run at all – it’s already part of the ECU; “Denso, Magneti Marelli – they know what they’re doing and have teams of very experienced engineers… ECUs just don’t go wrong.”

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. If anything goes wrong in that chain, be it a transient signal, processing glitch or brown-out, it’s possible that the last signal sent to the ECU – ‘open-throttle’ – could be maintained.

Motorcycles have a very harsh electronic environment, so it’s vital that any after-market parts are very carefully designed, and extremely resilient. Gareth is right to be obsessive about the quality of every solder joint on the quick-shifter parts.

Every circuit is meticulously checked under a microscope before assembly.

“Theoretically, it’s impossible for our system to fail in taking itself out of the throttle control circuit. When you command a shift, the processor runs self-checks – if it’s happy with all of those checks, it will then insert itself into the throttle circuit. When it does it, it starts a ‘dead man’s timer’ – this means that if the processor somehow froze, the timer would continue to run and still take itself out of the circuit, so an open throttle couldn’t be held open. And this all happens in less than a millisecond.”

Are quickshifters just for race bikes?

Not at all, though the sped advantages aren’t really going to make much difference on the road. While many riders will simply appreciate the sound and feel of a quickshifter, they can also be great for touring – the smoother the shift, the less you’ll see your pillion being thrown back and forth; no more helmet banging.

A smooth shift means the attitude of the bike is less affected during gear changes, which makes for a safer ride (though less so on the road, where you shouldn’t normally be that close to the limits of your tyres); HM Quickshifter sells more units to the track day and road market than all of its racing customers put together, despite its kit being on almost every race bike in pretty much every series besides MotoGP (where there are seamless gearboxes), and Moto2, which (for 2019 only) sees all riders having to use the switch-based shifters that come with the Triumph 675 motors.

Why do some quickshifters feel better than others?

Different brands of gearbox feel lighter or heavier than others in their operation – the Yamaha Niken quickshifter, for instance, feels a lot more heavy and clunky than the one fitted to the MT-10.

The mapping of the ECU, the mechanical set-up and even the chain tension all contribute to the feel of a gear shift, and hence the quickshifter.

The time the engine is cut for the gear shift to happen will also make a big difference – too short and the gears will grind; too long and you’ll feel the bike dive on upshifts or lurch on downshifts as the power to the spark plug coils is cut for too long, or the throttle blipped too much respectively. Of course, making the gear changes happen as quickly as possible don’t just smooth things out (which is important to prevent the bike becoming unsettled); in racing, those fractions of a second all matter.

A big V-twin is more likely to have a heavier, clunkier gearbox than an inline four, and no quickshifter can give seamless upshifts at every speed and throttle opening – at town speeds for instance, the gearbox is turning relatively slowly, so with the best will in the world things will all happen at a lower speed, and getting a smooth shift without using the clutch will typically be more tricky. You also need to be accelerating for clutchless upshifts, and off the throttle for downshifts, not just knocking through the box for motorway comfort as without that change in loading inside the gears, the float won’t be found that allows for a smooth clutchless shift.

The HM Quickshifter plus with the OE Yamaha shifter.

Does a quickshifter damage a gearbox?

Gareth explains that a properly set-up quickshifter should cause less wear to a gearbox than even a shift using the clutch – if the change matches the float in the gears precisely, the edges of the dogs will suffer less wear; “When we started in business, I made a thousand quickshifters and sold them at cost to the motocross market with the agreement that we could analyse the engines and their oil to see what was happening.”

A clutch still has a certain degree of drag, so while engaging it will start the slowing of the engine that will give the opportunity for a smooth shift, friction in the system means there’s still some drive, so the moment of float is still important.

“Case in point,” says Gareth. “The first BMW S1000RR had a big issue with race gearboxes blowing up – they’d change ’boxes between each race. BMW came to us and asked if we’d have a look; we just took one of our standard shifters off the shelf and said ‘here, try that’. They’ve not had a single gearbox failure since.

“One of the reasons we’ve not been able to get our kit onto the production line [besides the high manufacturing costs being restrictive] is that we’re not able to guarantee the levels of just-in-time manufacturing they’d require. Though you can get HM Quickshifters on some of the limited-run special BMWs.

What's the best quickshifter?

The sprung switch inserted into the gear-change mechanism of most quickshifters takes away the direct action of the selector – how much you feel it will depend on the weight of the spring in the switch and the length of its travel; on some bikes, like the new Kawasaki Versys 1000SE, it can be really noticeable. A bike with a downshifter will have this additional travel in both directions.

This is what’s inside that OE Yamaha MT-09/Niken quickshifter – you can see it’s simply a plunger with a stiff spring and a microswitch. It costs £303.36.

A mechanical switch will wear over time through arcing and movement, and the spring (which will also wear) needs to be precisely matched to the force required on the selector drum to change gear. Some manufacturers describe their quickshifters as using ‘strain gauge technology’, but these are still a traditional switch.

There are currently no motorcycle manufacturers using strain gauges in their shifters as standard (they’re just too expensive), though KTM does have an alternative to the switch in a sensor at the selector rod that detects movement in either direction. This makes for a much more direct feel to the gear selector, but it’s very sensitive; if you don’t make a positive change with the lever, it can cut or blip the engine before you change.

A strain gauge like that in an HM Quickshifter eliminates any moving parts, so the direct feel of the gear change is maintained, but it will also allow the setting of its activation to match the force required to change gear.

The strain gauge fitted inside an HM Quickshifter unit is a tiny, but incredibly precise device.

Every gearbox is going to have a different feel and a different amount of force needed to shift it (even, to a small extent, between two versions of the same bike) – a properly implemented strain gauge can very accurately measure the force applied, so that it can cut the engine or blip the throttle at a really precise and consistent pressure. With a switch or sensor system, there’s more of a risk of a missed gear if the rider doesn’t make a positive shift in one motion; too light a switch and preloading the lever ready to change can see the engine cut too early. Too stiff and it can change after the dogs have come under load from the selector.

Beyond a strain-gauge quickshifter is the seamless gearboxes used in MotoGP, but these hugely complex units require a dedicated mechanic to be regularly changing the fine parts. Honda’s Dual Clutch transmission is a (albeit heavy) alternative, though Yamaha has filed patents that might see the first seamless transmissions making their way to road bikes.

Can I swap out my bike’s spongy quickshifter?

Yes, you can – HM Quickshifters can be used in place of a standard unit, allowing for the direct feel of a strain gauge shifter. This can often be done while still using the ECU to make the engine speed changes, though you won’t be able to adjust the duration of the shift. The alternative is to let the shifter do the work, in which case it’ll be plugged into the leads to the coils (and the throttle, in the case of a down-shifter).

Can you fit a quickshifter to any bike?

An HM upshifter can be fitted to pretty much any bike, though some coil packs can be problematic. The biggest restriction is having a selector arm long enough to accommodate the strain gauge unit. In this case though, the HM Lever Plus can sometimes be used, which is a gear lever with the strain gauge built in.

Downshifters – or auto-blippers – are more tricky, as the bike needs to be ride-by-wire. 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 01795 429 168, or email info@hmquickshifter.com.

HM Quickshifter Plus review

The Yamaha Niken that I’ve had on long-term test uses the same engine and gearbox as the MT-09. I’ve found gear selection to be very harsh and clunky, but after meeting the team at HM Quickshifter, they installed the upshift-only £408.50 HM Plus unit.

Out of the box, the kit comes with a sensitivity of 50% and a kill time of 60ms, and while it was fitted for me, it’s a simple process that just needs the loom plugging between the plug coils, and a neutral cable being wired to a reliable earth, or straight to the battery.

For the first few miles I was disappointed – shifts were more positive feeling, but the gearbox still felt rather heavy and lumbering. But then I tried loading the gear lever, and just rolling off the throttle (as I often would with the OE quickshifter) – the bike snicked into gear much more easily, indicating that the shifter wasn’t yet sensitive enough for my riding style.

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. After a couple of tweaks, I found 80% worked great with the Niken – once that was done I could snick much more smoothly up through the ’box than I ever could with the OE shifter.

If I’d set it too light, I could have started to get missed gears as the shifter might activate before the shift was complete, and for a racer it’s often the opposite way around – for the fastest, most positive shifts the sensitivity will be set lower, so that more pressure needs to be applied before the gear change happens.

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). Think about that for a moment – I’m no racer, yet I could feel the difference that 10ms less kill time made to riding the Niken. By my maths, at about 7,000rpm, that’s just two sparks. There’s some clever stuff happening in the HM quickshifter beyond ‘simply’ killing the power for a set time.

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). The only slight downside is that in sixth gear, the unit doesn’t know it’s in top, so push up and you’ll still momentarily cut the engine. It’s very brief though, and takes a hard and deliberate push on the lever, so it’s not bothered me at all.

The HM Quickshifter Plus isn’t much more expensive than the OE Yamaha part, though if you already have a bike with one fitted, despite improved performance, justifying the cost will be harder (unless you go for a model than adds extra feature, like a down-blipper). Owners of bikes like the earlier MT-09s that didn’t have quickshifters will really value this HM version though.

It’s not a cheap accessory (though compared to the £303.96 of the OE part it’s not that bad), but when you consider that it’s hand-mad in the UK, and the level of design that goes into making something so slick, refinable and reliable, if you want the smoothest possible shifts – be it for comfort or for speed – it’s an outstandingly high-quality piece of kit. And while the shift rod and wiring loom will be specific to your bike, you can always swap these out, typically for around £10 and £50 respectively, making it more of a long-term investment.

Looms can be bought to suit most bikes.

While I didn’t need to use it, it’s reassuring to know that Gareth and the team at HM Quickshifter are more than happy to help any customer over the phone, email or even video streaming – this isn’t a company that’s only there to support race teams, and checking forums online it’s clear that the customer service offered is exceptional.

For £31.50 more, the HM Plus SS adds ‘seamless shift’, so called as it’s designed to be close in feeling to a seamless gearbox by using the strain gauge to ‘feel’ when the shift has completed, taking the ignition kill duration down to the minimum time possible at any speed and gear – if it takes you 30ms to shift gear, that’s how long the ignition will be killed for, rather than a set duration. It won’t be noticed by many road riders, but on track it can make a real difference.

With the Niken going back to Yamaha as I take on a Verys 1000 SE, it’ll be interesting to try replacing the spongy stock Kawasaki shifter with an HM unit, but on the MT-10 I’ll also be testing the new HM Stand Alone Blipper system, which adds downshifting to bikes that don’t already have it. The Lite version costs £600, while the Pro, at £720, is more race-focussed, with intelligent auto-warmup and a pit-lane limiter as standard, with launch control, engine brake control and anti-wheelie to be released shortly through a software update.

Want to know more?

An in-depth animation showing how a motorcycle gearbox works