Yamaha Mio Gravis : The Mio for Grownups

Contrary to industry rumors before its official launch, the Gravis will not be replacing the Mio i125 but rather an addition to Yamaha’s market domineering lineup of automatics. In price and specs, the Gravis should sit nicely in between the Soul i125 and the Aerox 155. But unlike the youth oriented Mio Sporty, i125, Soul i125, and Aerox 155, the Gravis is targeted towards a more mature market (more on that topic later).

But what exactly makes the Gravis any different from its existing lineup of excellent 125cc automatics? The answer is gravity. According to Yamaha the name Gravis was actually derived from the word gravity, the invisible force by which the weight of an object draws towards the center, which was probably used to describe the unusual placement of the Gravis’ fuel tank, which is under the footboard. This design not only frees up significant space under the seat, where the fuel tank are located on most scooters, it also shifts the center-of-gravity lower for better stability and weight distribution, while still having a genuine step through design. To make loading fuel much easier at the gas pumps, Yamaha placed the fuel filler lid behind the front apron, just below the left handlebar. This can be accessed by pressing a button labelled ‘fuel’ next to the integrated key shutter. The button below it unlocks the seat to access the underseat compartment with a 25 liter capacity, enough to fit a full face helmet.

25 liter capacity under-seat compartment

The Gravis is powered by an air-cooled, single cylinder, sohc, 2 valve motor that features Yamaha’s Blue Core principle of extracting more power by using less fuel. This was achieved by optimizing the valve angle design that enhances the tumble flow effect for better combustion of the air-fuel mixture, and a hemispherical combustion chamber that results in a higher compression ratio. Despite not having liquid-cooling, Yamaha uses DiASil cylinder head liners that dissipate heat three times faster than steel. This cooling effect is complemented by a piston cooler that sprays motor oil underneath the piston. Friction losses were further reduced by using roller-rocker-arm and forged piston for lower reciprocating mass and minimize vibration compared to cast pistons. A new Smart Motor Generator, or SMG, silently starts the engine without using a starter motor and also reduces weight. Curiously, the Stop and Start System is not offered on the Gravis. Perhaps in the future, Yamaha?

One, or rather two, of the more defining characteristics of the Gravis are its wheels. Instead of the more popular 14-inchers found on most scooters in its segment, the Gravis uses smaller diameter 12-inch wheels. These are offset, however, by taller profile and perhaps more importantly, by wider tubeless tires of 100/90-12 size in front and 110/90-12 at the back. These tires not only offer a better ride but also bigger contact patches for better road holding grip. Stopping duties are handled by a hydraulic single disc brake up front and a mechanical drum setup in the rear that feels adequate for everyday riding. Interestingly, there’s an ABS ring and sensor in front but sadly no ABS option for the Gravis. Perhaps in the future, Yamaha? Suspension setup are just basic telescopic in front and single shock absorber at the back.

Riders who plan to buy a Gravis for TNVS (Transport Network Vehicle Services) purposes will be delighted to know that it already comes standard with a 12 volt power socket to keep their mobile phones’ battery topped up at all times. You just have to provide your own USB adapter and a cellphone holder, though. They will also appreciate the wider than usual seat with ergonomically shaped and soft padding for extended time on the saddle. Also standard is a hazard lamp switch. The nicely shaped LED headlight provides ample illumination at night. The instrument panel is composed of a simple LCD screen that shows speed, fuel level, odometer/trip, and voltmeter. A kickstarter is still standard on the Gravis, a basic feature that’s fast becoming a rarity on scooters these days.

The Mio Gravis comes in matte red, matte black, or matte green colors. Our test unit is the matte green color with simple white stripes that we think looks elegant and complements the subtle lines and rounded curves of the Gravis really well. Some call the Gravis a baby Aerox but we beg to differ. The Aerox looks decidedly aggressive like a sport scooter should and it is designed to appeal to a much younger crowd. The Gravis on the other hand has a more understated, toned down styling and its lack of edgy and colorful graphics suggests it is targeted to a more mature audience (25 to 45 years old). Compared to the Mio i125 and Soul i125, the Gravis looks relatively conservative.

If the Gravis appeals to you then you probably want your scooters to be unintimidating, comfortable, relatively fast yet fuel efficient, easy to maintain, and easy to ride. The Gravis offers all of this, and much more. We love that its low center of gravity not only offers low and high speed stability, it also feels surefooted at high speeds. We love that its fat tires provide confidence inspiring grip in wet and dry riding conditions. We love that you no longer need to open the seat when refuelling. We love that it has a large underseat compartment. We love its step through design and flat footboard. We love that it has a standard 12 volt power socket. We also love that it has a comfortable seat. So what if it doesn’t have liquid-cooling? That only makes the Gravis lighter at 100 kg fully fuelled and ready to go. Also, less complexity means fewer mechanical problems in the long run.