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Razor SX500 McGrath Dirt Bike (Specs & Review)

In recent years, a growing number of dirt bike options have become available for young riders. Carbureted 50-cc Yamahas, KTMs, or Suzukis no longer monopolize this sub-segment. Moreover, the timely advent of electric bikes like the Razor SX500 McGrath Dirt Bike in the last decade has made make-and-model selections diverse and better suited to consumer preferences.

The Razor SX500 is an MX-style motorbike made for the young dirt rider. Featuring a 500-watt electric motor, variable-speed chain drive, dual-suspension, and Jeremy McGrath graphics, SX500 is the perfect tool for fostering friendly competition and fun while going for a spin from hell to breakfast.

Its McGrath-inspired build, supercharged motor, and high-torque drivetrain are proof of the thoughtful planning that goes into the making of the Razor SX500. Learn about its specs, features, customer reviews, and more, as this guide helps steer you towards your next big purchase.

Young Child Dirt Bike

About Razor SX500 McGrath Dirt Bike

Calling the Razor SX500 McGrath the best electric dirt bike in the market may be a bold statement. But given its aptness in handling speed, dirt, and MX-style tracks, it is deserving of such a description. It is on par with Suzuki DR-Z50, Honda CRF50F, Yamaha TT-R50E, and KTM SX 50 in the dirt biking segment. Furthermore, it is one of the most reasonably priced e-bikes, rivaled only by the Kuberg Cross X-Force Pro.

However, the price point is not its best attribute. What owners love most about the bike is its Supercross orientation and unique framework geometry personally designed by SX champ Jeremy McGrath. On the exterior, the SX500 looks very much like the motocross wheelers used by the famed “King of Supercross.” But for serious, in-training racers, there is still a lot to be had in the bike’s ability to support freestyle motocross and BMX riding.

Razor Dirt Rocket SX500 Specs & Features


Instead of a carburetion or fuel injection system, the Razor SX500 utilizes a 500-watt electric motor operated with the help of a 36-volt battery network. This makes the MX bike hassle-free and eco-friendly due to the absence of toxic fumes or gases resulting from combustion. Plus, it lends to a top-speed rating of up to 15 mph (24 km/h) at full pelt.


A variable-speed high-torque chain drive delivers power to the wheels and is mated to the SX500’s supercharged motor and twist-grip acceleration control. The combination lends to ease in climbing steep inclines and traversing challenging terrains. It is not clearly stated in the service manual whether the powertrain consists of multiple gears with derailleurs or internal gear hubs. Nonetheless, maintaining the right-spoke tension and chain-sprocket alignment is extremely important. The same goes for applying an ample amount of lubricant on components to keep them from grinding or drying up.


The Razor SX500 is brought to life by three (3) rechargeable, 12V lead-acid batteries, a control module, and a triple-fuse box. There is no specific battery format like UB12120ZH or UB12150K recommended for the SX500 McGrath, as one’s choice will depend on preference for an extended-range battery type or something similar to stock.

Modification kits for the Razor SX500 Dirt Bike are available for mechanically savvy owners and are already pre-wired. They simply require mounting a sizeable controller and a larger battery pack fitting four to five batteries to the stock frame. The advertised run time for a fully charged battery network is 40 minutes of continuous use. However, this can reach up to 75 minutes – depending on the terrain, driving speed, and rider weight (among other factors).

Tires & Brakes

Its tire-and-wheel assembly is one of, if not the most outstanding feature of the Razor SX500. The said assembly offers a hand-operated, dual-disc braking system – reliable front and rear brakes providing on-tap halting power, not to mention an added safety measure for young riders. The brakes pair with pneumatic, knobby tires that provide stability on irregular surfaces and motocross tracks.

Tread patterns of stock 16-inch front and 14-inch rear tires are engineered for enhanced performance on slick surfaces and cornering at narrow angles. These tires work nicely with durable brake discs capable of enduring high impact and preventing the rims from flexing out of shape. More importantly, the on-hand brakes are intuitive, boosting rider confidence while keeping youngsters safe.


Inverted, double-crown front forks and rear shock absorbers comprise the Razor SX500’s dual suspension system. Its components are enclosed in a sturdy steel frame with an aluminum beam and mated to oversized Supercross tread tires. Furthermore, adjustable riser handlebars aid with rider comfort and the dirt bike’s ease of maneuverability.


Overall dimensions of this mini bike are 1,422 x 914 x 622 mm (56 x 36 x 24.5 inches – L x W x H). Dry weight sans accessories is 44 Kg (98 lbs.). Despite its minimal mass, the SX500 can support a weight capacity of up to 79 Kg or 175 lbs., although long-time users advise keeping the rider weight limit within 63.5 Kg (140 lbs.). GVWR or Gross Vehicle Weight Rating is estimated at 124 Kg or 273 lbs. Upgrading the dirt bike with a 5-battery pack and mod kit may increase this figure by at least 7 Kg.


On the outside, the Razor SX500 McGrath is a faithful reproduction of the bike Supercross big shot Jeremy McGrath used to win championships. This concept is evident in the SX500’s special decals and is the only difference between a Razor MX500 vs SX500. Conversely, its green body color is representative of McGrath as a former spokesperson for Kawasaki dirt bikes. As for factory inclusions, a retractable kickstand, folding metal footpegs, #2 pro-racing number plate, and shatter-resistant plastic fairings came standard with the Razor SX500.

Cost of a Razor SX500 Dirt Bike

The original list price for the Razor SX500 McGrath Dirt Bike (view on Amazon) falls between $549 and $799.95, depending on where it was bought and whether promotions or Halloween specials existed the time of purchase. This base-price range applies to all production models – including auction listings and resale values. Walmart, Amazon, and eBay are good sites to check out if you want to get your hands on a brand-new or pre-owned bike.

Customer Feedback on the SX500

Child Dirt Bike Off-Road

The Razor SX500 McGrath Dirt Bike predominantly gets good reviews from youngsters and parents alike. Of these reviews, owners express their excitement over the supercharged motorbike. It is far from having the power, speed, and adeptness of a pro-class motocross racer. But in terms of fun factor, capability, and safety, it does not disappoint.

Ease of Use

For a motorbike without a conventional engine and lubrication system, the Razor SX500 is easy to drive. Features like its twist-grip throttle, dual-disc handbrakes, and fully adjustable handlebars make steering convenient and the bike easy to maneuver. Motorcycle-spec tires and stock dual-suspension prevent rollover and make for a smoother ride. Plus, the bike’s build renders it sufficiently stable and capable of handling rider weight of up to 175 lbs.


The run time of the battery is a different matter altogether. While others have reported up to 75 minutes of continuous use, most riders are not exactly happy with the 40 minutes it usually provides. They find this lacking, given the bike’s triple-battery network. Not to mention it takes 12 hours to completely charge the SX500.

While the battery’s limited service life is good news for parents who do not want their kids riding too far away, it can be troublesome for teenagers. A good workaround to this problem is purchasing a second (or third) battery to have on hand – either that or modifying the battery network to support four to five batteries.

Rider Comfort

Patrons are also conflicted with rider comfort. Although the SX500 is recommended for young riders 14 years old and over, its size does not seem to wholly cater to this age group. Despite its slim framework, adjustable-angle, and riser-style handlebars, taller kids find themselves having trouble riding the motorbike. The feel is nothing like a Monkey Bike, but youngsters with longer inseams may end up acquiring a bad posture putting their leg over this uncomfortable wheeler.


The main drawback of the Razor SX500 for most riders is the quality of its plastic components. This is not to say the bike compensates in dependability what it lacks in sturdiness. But as it turns out, this is the case for the SX500 McGrath. The front fender tends to break easily and is not advisable for storage in a garage where the temperature exceeds 50°C – 60°C. Moreover, it is not as impervious to a beating as young, aggressive teenagers would have hoped it to be, making it more suitable for kids aged 8 to 12 more than 14-year-olds.

About Razor

Razor (formally known as Razor USA LLC) is a California-based designer and manufacturer of manual and electric bicycles and scooters and an emerging key player in the dirt biking segment. Established in 2000 by Carlton Calvin and the JD Corporation, the firm made its presence known in the industry with its first-ever product – the Model A Scooter. It has continued to reinvent old-school scooters since and even added electric minibikes, personal transporters, skateboards, and the Razor Dirt Bike SX500 to its plethora of offerings.

Conclusion – Razor SX500 McGrath Dirt Bike

All in all, the SX500 Razor is an irresistible, sweet deal for novice and intermediate riders alike. For an MSRP of less than $800, you get to own this thumper with top-notch safety features, cutting-edge technology, and impressive workmanship. Sure, its speed and torque output may be slightly held back. Nonetheless, it is a dirt bike befitting motocross racetracks – an entry-level wheeler even in-training aggro-riders will find difficult to outgrow.