We've had our yellow Biktrix Challenger ("Dandelion") for several months now. Challenger is a fantastic and unique ebike.
I've been an avid "analog" bike person for several decades. I build up most of my bikes from frames, do self-contained touring, bikepacking, etc. I expect performance, utility and reliability from my bikes. Dandelion is our first e-bike. We recently acquired a property in Vermont w/ 37 acres of orchards, fields and rolling forests. I need a way to get around the property quickly and efficiently, and to haul loads of brush, firewood, tools, etc. The conventional choice is a UTV. I have zero interest in gas UTVs, and electric models are hard to find and very expensive. Also, many of the trails in the forest are singletrack, where a bike shines and a UTV is hot garbage. I have a 50 year old diesel Farm tractor for truly heavy work.
After extensive research, the Challenger seemed worth a try. Features that were appealing: (1) the fixed moped seat and step thru design. At 5'10" the position is not super-efficient for pedaling, although just fine for occasional bursts up steep hills. But it's great for easily putting my feet w/ heavy work boots down on the ground. And my wife at 5'4" and daughter at 5'7" can both comfortably ride Dandelion...critical for a shared property utility bike. (2) Dual suspension-this is no "enduro bro" rig, but the suspension setup is great for smoothing out rough patches in field and forest. (3) Power and simplicity, the rear hub motor delivers plenty of power and I prefer its simplicity to mid-drive units. Also, Challenger is street legal in Vermont. (4) Class 2 design makes sense for utility purposes. I usually operate in throttle only mode when I'm working.
After several months and many miles of heavy use, Dandelion has been perfectly reliable. Most of the time, Dandelion is pulling a Burley Flatbed trailer. The Flatbed is a great companion to the Challenger, and allows me to tow loads up to 100 pounds of firewood, brush, junk, tools, etc. All while easily staying under the max weight load specification for the bike. And sometimes I buzz down the road for a few miles to local farms to load the trailer w/ fresh food, cider, etc. That's the life, baby! This winter, Dandelion will be pulling a pulk (sled) to assist w/ some light duty trail grooming for cross country skiing. To facilitate, I have acquired some 20" x 4" fat tire chains from the folks at SlipNot Traction Systems.
Challenger is just a blast to ride. My teenage daughter loves cruising through the rows of apple trees in the orchard. A combination of Challenger's hefty weight and geometry make the bike surprisingly stable on steep (but not rough) offroad trails. Brilliant! It's refreshing to have a vehicle that's so darn fun to ride when I'm out doing heavy manual labor on the property.
Some points/suggestions to consider:
(1) The stock pedal assist settings are too powerful in the lower assist settings. See YouTube for how to fix. I revised to a linear assist level where level 1 is around 20%, up to 99% on level 5. A significant improvement. This enables a steady 5-6mph pedal assist pace when towing heavy loads in rough terrain. That was not possible w/ the stock settings.
(2) Get comfortable changing out the rear wheel. The drop out design requires removal of the rear brake caliper to remove the wheel. No biggie, but most bikes don't require that step. Be "in the know" ahead of time.
(3) Challenger is a heavy bike and its shape will not work w/ many bike stands. Figure out how you will service the bike. I like to turn it upside down on a smooth, protected floor. Make sure you move controls/screens out of the way if you use this method!
(4) Front brake is consistently noisy, despite trying the usual tricks to quiet it down. A pad change will likely resolve.
(5) If you install the optional front basket (recommended), the front light will bump into the front fender when the suspension fork compresses. This is mildly irritating, but I've decided to live with it. A smaller profile front light would fix the issue.
(6) Battery life is good, although I do not push the bike from a range standpoint most of the time. I bought a second battery during Biktrix's recent sale just to have it. Often, when working in the field, I can top up the Challenger on sun power using a 200W Bluetti solar panel and the excellent EcoFlow Delta mini (which I use to power tools in remote areas of property).
In summary, Challenger is great example of how e-bikes can "come into their own" by doing away w/ the typical design constraints and considerations needed for human powered-only bikes. For recreational riding, I stick w/ analog bikes. For utility purposes, ebikes like Challenger rock, while maintaining the relative simplicity and affordability of "bikes" as opposed to more complex, heavy "motor vehicles." Dandelion is a "right sized" tool for the job. And she attracts plenty of positive attention.