5 Of The Fastest 125cc Motorcycles, Ranked By Top Speed

There are a lot of riders out there who aren't interested in getting the biggest bike with the largest engine they can find. Some prefer a smaller bike that they can push to its absolute limits. 125cc motorcycles certainly aren't the biggest or the fastest bikes on the block. In fact, there are some places in the country where these bikes are considered too small to be street legal, and you can't legally take them on the freeway as their lack of power is deemed to be unsafe to keep up with the anticipated speed of traffic. Lower displacement typically means lower horsepower, which, in turn, means a lower top speed. That said, many of these bikes are pretty cool looking and some of them are quite fast.

Speed is measured in a few different ways when it comes to motorcycles. Many enthusiasts like to focus on how fast a bike can go from 0-60 MPH, as acceleration is often one of the most important aspects of riding. It determines how fast you can get up to the speed of traffic as well as how quickly you can accelerate out of other vehicles' blind spots. Having that extra bit of pep off the starting line also generally makes for a much more enjoyable riding experience. With smaller bikes, it's equally important to consider the top speed that they're able to achieve. This can determine which roads are safe to travel on the vehicle. For those who are thinking about getting a 125cc as a starter bike, here's a rundown of how fast some of the fastest models go.

First, we have the Suzuki GSX-R125. This represents the entry-level bike in the massively popular GSX-R series, which is arguably the line that first helped push Suzuki to stand alongside the sportier offerings from brands like Honda in the '80s.

In terms of design, Suzuki states that, "The GSX-R125's confidence-inspiring stability on the highway, nimble handling in turns, and easy maneuverability through traffic start with a modern chassis. A steel-tube backbone frame combines optimal torsional rigidity with light weight." This frame is propelled by a 124.4cc 4-stroke, 1-cylinder, liquid-cooled, DOHC engine with a 62.0mm bore, a 41.2mm stroke, and an 11.0:1 compression ratio. MCN states that this gives the bike up to 15 horsepower and 8.49 lb-ft of torque. The GSX-R125 has a telescopic front suspension and a link-type rear suspension. It also boasts LED headlights, a keyless ignition system, a remote-controlled answer-back function, and a full LCD dash display.

Reports on this bike's top speed are a little all over the place though. MCN claims this bike's max speed is just 69 MPH. That said, there are a few outlets that have reported higher performance. MCN states the top speed is 69 MPH, RideTo cites 70 MPH, FastestLaps says 71 MPH, and Piston Heads claims the bike can get up to 80 MPH.

Yamaha is one of the most popular motorcycle manufacturers on the market today, and it has two 125cc motorcycles ranked among the five fastest. The first of these is the company's 125cc sportbike: The Yamaha YZF-R125. This bike isn't currently available in the U.S. Those who are familiar with Yamaha's YZF-R series probably won't be too surprised to find its 125cc model in this list, as they have a reputation for both performance and quality across the board.

This bike also has the Deltabox frame and aluminum swingarm design. Yamaha states that, "the R125's next generation aerodynamic bodywork gives this lightweight Supersport a commanding big bike look and feel." This places the rider in a sportier riding position and reduces wind resistance. It isn't just the bodywork that's made for speed, though. This bike is powered by a EU5+ compliant 125cc 4-stroke, liquid-cooled, SOHC, 4-valve engine with large intake and exhaust valves, and a Variable Valve Actuation system. This grants the bike up to 14.8 horsepower at 10,000 RPM. On top of that, it also has a 5-inch TFT dash display with smartphone connectivity, R1-type clip-on handlebars and switches, LED headlights and position lights, traction controls, a 41mm KYB upside-down fork suspension in the front, and a link-type suspension on the rear.

Some outlets, such as MCN and FastestLaps have claimed that this bike tops out at 75 MPH, but RideTo lists its tops speed at 80 MPH, and North Cust custom tuning has claimed that they were able to get the bike as high as 83 MPH under the right conditions.

The Austrian motorcycle manufacturer KTM has carved a significant niche for itself in the small engines market. The KTM 125 Duke streetfighter has an avid fan base who love the bike's aggressive styling and easy ridability, but it isn't actually the fastest 125cc bike that the company makes. That honor goes to the KTM RC 125.

This is a Grand Prix-inspired sportbike with a trellis frame and a bolt-on subframe designed to improve stability at higher speeds. It's powered by a 124.7cc, liquid-cooled, single-cylinder, four-stroke engine with a 58.0mm bore, a 47.2mm stroke, a 12.8:1 compression ratio, and a 6-speed transmission. This gives the bike up to 15 horsepower and 8.9 lb-ft of torque — which is not insignificant for a bike with an engine of this size. The RC 125 also has Bosch 9.1 MB Two Channel ABS, a WP APEX 43 suspension in the front, and a WP APEX monoshock suspension in the rear, as well as other amenities such as a TFT dash display, LED lighting, and clip-on handlebars.

FastestLaps claims the lowest top speed for the bike, claiming that it can only get up to 71 MPH, but MaxAbout says 75 MPH, and MCN states that it's actually able to reach a top speed of 84 MPH. If accurate, this marks a significant step up from a lot of other 125cc bikes that tend to top out in the 60-70 MPH range, and even the Duke, which can only hit 80 MPH. This would make it the fastest 125cc motorcycle currently sold in America. That said, there are still a handful of bikes in this engine class that are even faster, sold in other parts of the world.

The second Yamaha to make the cut is the Yamaha MT-125. This is the only hyper naked motorcycle to make the list. This is another of the three featured bikes that aren't currently sold in America.

You might be forgiven for thinking that the MT-125 doesn't have the same aerodynamic qualities designed to emphasize speed and turning performance that many of the other, more sport-oriented, bikes on this list do, but according to Yamaha, its "Deltabox style frame and aluminum swingarm deliver light and sporty handling, as well as impressive comfort and confidence at higher speeds." The MT-125 is powered by a EU5+ compliant 125cc, liquid-cooled, SOHC, single-cylinder, 4-valve engine that features Yamaha's proprietary Variable Valve Actuation system. It has a 52.0mm bore, a 58.7mm stroke, and an 11.2:1 compression ratio. All of this adds up to an engine that can deliver 14.8 horsepower at 10,000 RPM and 8.5 lb-ft of torque at 8,000 RPM. It also has high-spec 41mm upside-down front forks and built-in traction control.

FastestLaps reports that the latest version of this bike can only get up to about 71 MPH, and Moto Trips says 78 MPH, but MCN reports that this bike is able to reach a top speed of up to 80 MPH. That's reasonably fast, but the 2014-2019 version of the bike was even faster. MCN reported that model had a full 15 horsepower, with 9.15 lb-ft of torque, and was able to reach a top speed of 87 MPH — meaning that this older version of the bike edges past the KTM RC 125.

Finally, we have the fastest bike on our list. The Italian-made Aprilia RS 125 is technically the fastest 125cc bike on the market today — though its placement at the top of the heap comes with a few caveats.

The RS 125 is a sports bike that Aprilia states was "inspired by the aggressive lines of its big sibling, the RS 660, an icon of a new type of two-wheeled sportiness and with a look that is all about attention to detail." It has an aluminum frame that is designed to be light, while simultaneously balancing stability and handling. Inside the chassis, the bike is powered by a EU5+ compliant 124cc liquid-cooled, single-cylinder engine with four-valve distribution. MCN reports that this gives the bike up to 15 horsepower and 7.7 lb-ft of torque. It also has a triple LED headlight, an LCD display, traction control, and dual-channel anti-rollover ABS.

The modern standard version of this bike tops out at about 75 MPH (via Motorbike Catalog), which would put it at the bottom of our list, but much like with the MT-125, the fastest version of this bike isn't the newest. The older 1995-2012 models of the RS 125 had a two-stroke Rotax engine that was significantly more powerful. According to MCN, this version of the bike had a top speed of 93 MPH. This would already make it the fastest 125cc bike on the commercial market, but there are also several unverified reports on forums from riders who have claimed that they de-restricted the bike and have been able to achieve speeds in the 100-110 MPH range.