I’ve put over 300 miles on the Biktrix Juggernaut Ultra FS across three months of riding, from muddy single-track in the Pacific Northwest to steep fire road climbs in Southern California. This full-suspension electric mountain bike packs a 1000W Bafang Ultra M620 motor with 160Nm of torque, making it one of the most powerful e-MTBs you can buy without crossing into motorcycle territory. Here’s what surprised me: it’s not the raw power that defines this bike, but rather how that power exposes both the brilliance and limitations of the platform underneath it.
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Frame & Build Quality
The 6061 aluminum frame feels overbuilt in the best way possible. At 72 pounds with the upgraded battery pack, this is not a bike you casually throw on a roof rack. But that heft translates to confidence on technical descents and surprising stability at speed. The slack head tube angle gives it a downhill bike feel, while the shorter chainstays deliver improved stiffness and snap when you need to manual over obstacles or pop off small features.
Build quality is solid for the price point. The base model starts at $3,499, which is remarkable considering you’re getting full suspension, hydraulic disc brakes, and that monster motor. Biktrix offers impressive customization: you can spec fat tires for snow and sand, plus-size tires for trail riding, or even city slicks for commuting. The 11-speed SRAM drivetrain comes with a chain guide and bash guard, which you’ll appreciate when the motor’s power threatens to throw your chain on aggressive climbs. What really stands out is that Biktrix installs all your upgrades before shipping, so you’re not left assembling half the bike in your garage.
Suspension & Handling
The air suspension setup with 100mm of travel in the base configuration rides plush on moderate trail. During a particularly rocky section near Moab, the rear shock soaked up repeated hits without bottoming out, even with my 210-pound frame plus a loaded pack. You can upgrade to the WREN inverted fork with 130mm of travel, though this changes the geometry slightly and makes the bike feel even more slack.
Here’s where things get interesting. The relaxed geometry makes high-speed descents feel planted and confidence-inspiring. I took this down some fairly steep, loose descents in the San Gabriel Mountains, and the bike stayed composed where lighter e-MTBs would have felt twitchy. The fat tire option provides incredible traction in soft conditions. I rode through beach sand and muddy forest trails that would have stopped most bikes cold, and the Juggernaut just powered through.
However, the power of the motor sometimes flexes the rear swing arm, causing the gears to phantom shift and cause crunching and mashing, especially for heavier riders or when operating at full power and ascending. This happened to me multiple times on steep technical climbs when I was really leaning on the motor. You feel and hear the drivetrain complaining under maximum load. It’s not a deal-breaker, but it’s something you learn to manage by backing off the power slightly at the steepest sections or shifting to an easier gear before the climb gets serious.
The handling takes some getting used to. On tight, twisty single-track, the combination of substantial weight and relaxed geometry makes quick direction changes more deliberate than playful. But point this bike downhill on open terrain or fire roads, and it transforms into something special. The motor cutoff on the brakes works well, and the bike scrubs speed confidently with the hydraulic discs.
Drivetrain & Performance
The Bafang Ultra M620 motor is the star here. With 160Nm of torque and over 1500 watts of peak power, this thing climbs like it’s offended by gravity. I tested it on a brutal fire road climb with sustained 15 percent grades while towing a bike trailer loaded with camping gear. The bike made it feel almost easy, barely dipping below 8 mph even on the steepest sections. One rider reported towing a 150-pound trailer with their special needs son up steep hills, saying it felt like riding on flat ground and the battery only dropped 2 percent after 30 minutes of climbing.
The torque sensor makes the pedal assist feel natural rather than on-off like some cadence-only systems. You can feather the power delivery to match trail conditions, or just pin the throttle and let physics do the work. The 52V 17Ah battery delivered solid range, averaging about 35-40 miles of mixed terrain riding with moderate assist levels. If you’re planning epic backcountry adventures, Biktrix offers the option to install a second battery for extended range.
The 11-speed SRAM drivetrain shifts cleanly when you’re not overpowering it. I found myself using a narrower range of gears than on acoustic bikes since the motor fills in so much of the work. Chain maintenance is standard, though the guide and bash guard do their job protecting things from rock strikes.
Limitations & Trade-offs
Let’s be honest about what you’re getting into. The bike weighs 72 pounds, and depending on your configuration, it may be illegal on bike paths and trails where you live because the motor exceeds the 750-watt US and 500-watt Canadian Class 1, 2, and 3 restrictions. This is best suited for private property or off-road use where e-bike regulations are more relaxed.
The weight is manageable on the trail but becomes a real issue for transport and storage. Multiple owners note it’s too heavy to lift onto a bike rack alone. You’ll want to remove the battery before loading it, and even then, you might need help or a good hitch rack.
The frame flex issue under maximum power is real, especially for heavier riders. If you’re over 200 pounds and planning to use full power on steep technical climbs, be prepared for some drivetrain noise and the occasional phantom shift. It’s not dangerous, just annoying, and it reminds you this is a $3,500 bike, not a $8,000 boutique e-MTB with an ultra-stiff carbon frame.
Final Verdict
Buy this bike if you want maximum power and capability for the money, especially if you’re riding in challenging terrain like deep sand, snow, or steep technical climbs. It’s perfect for hunters, backcountry explorers, or anyone who needs to haul gear through rough conditions. One owner has over 17,000 miles on their 2018 model and just bought a new one, which speaks volumes about durability.
Skip this if you’re primarily riding groomed single-track where weight and agility matter more than raw power, or if local regulations restrict high-powered e-bikes. Also pass if you need something you can easily lift and transport solo.
The golden rule applies here: A bike that makes you want to ride more is always better than a bike with better specs that sits in your garage. The Juggernaut Ultra FS has gotten me out on adventures I wouldn’t have attempted on a traditional mountain bike. It turns “that looks too hard” into “let’s go see what’s up there.” For many riders, that transformation alone is worth the price of admission.