Tom's Guide Verdict
An excellent upright powerhouse that can handle rough routes without demanding that the rider be a mountain bike expert, the Biktrix Stunner X is worth the price, particularly for all-season bikers.
Super solid ride in the rough
Good hill-climbing power
Smooth mid-drive motor
Awkward controller will force you to read the manual
Why you can trust Tom's Guide
Battery: 840 Wh (as tested)
Max estimated range: 40 miles
Max assisted speed: 20 mph
Motor: Bafang 750w mid drive motor
Gearing: Shimano Alivio 9-speed
Wheel diameter: 26 inches
Weight: 65.8 pounds. (with large battery)
In the "go big or go home" category of ebikes, the Biktrix Stunner X is brawnier than most. But it's got a purpose: handle all weather--good, bad, or indifferent--and keep the rider comfortable and in control. It does an excellent job of doing exactly that.
With a commuter-like stance but power and components more typical of mountain bikes, the Stunner X can deal with mud, snow, or pot-hole dotted city streets. It's got enough of a kick to get you up a gravel hill, and enough padding so that your ride doesn't turn into a torture test. Sure, at $2,798 (as tested), the Biktrix Stunner X costs more than some other, similarly positioned ebikes, but those models lack the power and quality components you'll find here. Conversely, it costs a lot less than some svelte commuter bikes that usually have smaller 500 Wh batteries. Read the rest of our Biktrix Stunner X review to see if it’s right for you.
Biktrix Stunner X: Price and availability
Available direct from Biktrix.com with free shipping, Biktrix offers a full lineup of ebikes, many of which are focused on the mountain and trail riding category. The Juggernaut series are straight handle bar, all-terrain models that start at around $2,000 and go all the way up to the $4,099 Juggernaut Ultra Beast with a 1440 Wh battery and 1,000 watt mid-drive motor.
Biktrix also makes specialty folding and cargo bikes, as well as a more affordable city bike Swift line. The latter models have shorter electric ranges but start at just $1,349.
The Stunner line of Biktrix ebikes sits somewhere in between: part mountain climber, part urban rider. The entry level LT model is $2,199, and the Stunner X starts at $2,499, before you start adding upgrades like the 840 Wh battery that boosted the price of our tester by $299 for a total of $2,798.
Biktrix Stunner X: Design
Coming from a country where the beavers gnaw through underground Internet cables (yes, that's a thing in Canada), Biktrix bikes are designed to deal with less than perfect weather and road conditions. If you want an ebike that can handle all four seasons, including snow and mud, you've come to the right place.
The Stunner X, which the company describes as an off-road cruiser, uses a heavy-duty step-through aluminum frame outfitted with comfort-enhancing elements. There are the wide, bull-horn handlebars, a heavy compression fork up front to absorb bumps and berms, and a wide, dual-spring seat with full padding to keep your derriere from suffering on hilly terrain.
The Shimano 9-speed gears are paired to a Bafang 750W mid-drive motor in the crankshaft, which makes for responsive electronic assistance, plus a large 1008 Wh battery to back it all up. Our test model had Kenda Juggernaut 26 x 4 fat tires and big aluminum fenders to keep the dirt off our jeans, plus a big rear rack to handle large panniers.
To bring this hulking beast to a stop there are Tektro dual-piston hydraulic brakes so you still feel like you're in charge of the Stunner X, rather than the other way around.
Biktrix Stunner X: Performance
Subtle is not a word that comes to mind with the Biktrix Stunner X. When you first shove off, its initial electric boost can take you by surprise before you get your hands situated on the brakes. You quickly learn how to rein in the power. There are 5 levels of pedal assist, as well as a thumb throttle for full-on electric driving, restricted to a top speed of 20 mph. (The Biktrix website notes you can request that a bike be unrestricted for a top speed of 28 mph — but only for off-road use.)
Roaring around on dirt, gravel and sometimes simply rocky roads in Vermont, we bounced around a fair amount with the Stunner X. There's no rear shock system, but the combination of size, tires and spring-loaded seat meant we didn't have to suffer unduly. The front RST Guide shocks handle the rest, and the bike felt stable and in control in dirt and slush.
After a few days of shake-down runs, we found the Stunner X delivered a reassuring ride in the rough. The pedal assist was responsive and we ultimately found it very helpful launching this big bike from a standstill. The 4-inch wide tires were unperturbed by dirt and gravel and also did well on the messy rutted roads during what Vermonters affectionately refer to as mud season.
Going all electric, the throttle is quick to respond but can make the rear wheel spin easily in snow. On the other hand, its 120Nm of torque got us up all the hills we threw at it.
As for handling, the Biktrix Stunner X is not a bike you toss around corners or wiggle through narrow gaps. And you need to be careful on tight turns not to push the electric assist or you'll find yourself thrashing through the underbrush. Still, the big fenders kept the muck off our jeans, and mud-slicked roads were no problem. Indeed, after a while rather than avoiding it, we started aiming for the mud and slop.
Maneuvering the bike when you're not in the saddle can be work. A walking assist electric mode (you engage it pushing the minus button next to the throttle) triggers the motor to drive the bike at about 3.5 mph. It's a big help if you have to push it uphill.
The only weak link in the Stunner X package is its Bafang controller. The monochrome display is certainly not the epitome of ease of use. Figuring out how to turn on the included head and tail lights will send you looking for the manual (you have to turn on the bike and then push and hold the plus button). But this isn't unique to the Biktrix bike.
We find the Bafang C961 controller needlessly difficult to master. It uses three-button sequences to make changes, zero out the odometer, etc. So it takes some practice to get used to its operation. For example, you have to press the power and minus button to clear the trip distance; to get to the advanced setting mode, you have to press and hold the plus and minus buttons and then press the power button eight times. You get the idea.
Biktrix Stunner X: Battery life and range
The battery is rated for 40 miles, which is typical for this price range. But as with all ebikes, this is a difficult specification to pin down.
Battery mileage depends on the terrain, weight of the rider, how aggressively you use the throttle, and even the weather. We found it to be comparable to similarly rated bikes we've tested — although we were more aggressive with the Stunner X.
Biktrix Stunner X: Competition
With slick commuter ebikes from major bike companies, such as Gazelle, Specialized, and Trek easily topping $4,000, the Biktrix Stunner X at $2,798 looks like a deal. It's not as elegantly designed as those more expensive models, and, by any measure, it's heavy. But it is also durable and built with quality components.
There are a raft of less expensive ebikes increasingly aimed at the same market. Many are favored by delivery people and do some serious daily duty. Models like the Turboant Thunder T1, for example, cost about $700 less. But those ebikes typically use hub motors, rather than smoother mid-drives, favor less expensive components, and smaller 700 Wh batteries.
Biktrix Stunner X: Verdict
What was once a niche design — a rugged, upright cruiser with power to handle off-roading — is quickly becoming an ebike design for all seasons. As such, the Biktrix Stunner X is one of the best electric bikes in this class. Unlike less expensive models, Biktrix uses premium parts here and a mid-motor design that should prove more reliable and require less maintenance. And we're all for that. It means more riding, especially with the Stunner X, which doesn't care what the weather is like outside.
John R. Quain has been reviewing and testing video and audio equipment for more than 20 years. For Tom's Guide, he has reviewed televisions, HDTV antennas, electric bikes, electric cars, as well as other outdoor equipment. He is currently a contributor to The New York Times and the CBS News television program.