When I unboxed and built the Mokwheel Obsidian, the dual suspension made it really comfortable, and its optional inverter let me charge one of my Toro yard tool batteries off the bike. That bike runs a rear hub motor. The Mokwheel Onyx ST keeps the fat tires and full suspension but moves the motor to the middle of the bike, and Mokwheel calls it the most capable fat tire e-bike in its lineup. I haven’t ridden it. Everything below comes from Mokwheel’s official Onyx ST page, checked on Oct 28, 2026 and linked at the bottom.
Why the motor’s position matters
A mid-drive motor sits at the cranks and drives the chain, so it works through the bike’s gears, while a hub motor spins the rear wheel directly. Mokwheel’s own FAQ makes the same point, saying a mid-drive offers stronger torque, better climbing and more balanced weight. On the Onyx ST, that motor is rated at 750W, with 1000W continuous, a 1300W peak and 210+ Nm of torque. It pairs with a torque and cadence sensor and a Shimano 10-speed, two more gears than the 8-speed on my Obsidian.
The Onyx ST is listed as Class 2/3, with a 20 mph throttle and pedal assist up to 28 mph. The throttle is a thumb throttle. Check your local rules in our e-bike laws hub.
Built for rough ground
Up front is a 135mm dual-crown hydraulic fork with adjustable rebound, and the rear uses a DNM 50mm center shock. The tires are 26 x 4.0 in puncture-resistant fat tires. Braking comes from Tektro HD-E3940 four-piston hydraulic brakes, and the levers cut motor power when you pull them. Mokwheel adds a dropper seatpost you control from the handlebar, an adjustable stem, and what it calls a hydraulic two-stage adjustable seat.
Mokwheel’s reviews section quotes a writer describing it as a utility machine for backcountry riding, hunters included, where power, range and cargo capacity matter more than nimble handling.
Battery and range
The battery is a 48V 19.6Ah pack, 940Wh, which Mokwheel says meets UL standards and is rated IPX7. The whole bike is rated IPX6. Range is listed at 60 to 80 miles, and the charger is 48V 3A. Mokwheel also sells its inverter as an add-on, and on Oct 28, 2026 the Onyx ST page listed it at $79.99, down from $599.99.
Size and weight
The ST in the name means step-through, and there’s one size for riders from 5’5” to 6’7”, with a 20 in standover. Mokwheel lists the weight as 88 lb in the spec table, and the comparison chart on the same page says 89 lb. Either way, it’s a heavy bike. Payload is listed at 560 lb.
How it fits with the Mokwheels I’ve reviewed
The Obsidian is the closest bike I’ve ridden from Mokwheel. Both use a 48V 19.6Ah battery, 26 x 4.0 tires, full suspension and a 560 lb payload rating, by Mokwheel’s numbers. The Onyx ST adds the mid-drive, the 10-speed, four-piston brakes, the dropper post and a step-through frame. It also adds roughly 11 lb over the about 77 lb Mokwheel listed for the Obsidian, and it costs $1,600 more: the Obsidian was $1,799.99 on Oct 28, 2026. I also rode the Mokwheel Scoria, a step-through fat tire bike I took on dirt roads and gravel paths, which has a front fork only. For more options, see my best fat tire e-bike guide.
FAQ
Have I ridden the Mokwheel Onyx ST?
No. I haven’t ridden it. I rode and filmed the Mokwheel Obsidian and Scoria, and this page compares the Onyx ST with them using Mokwheel’s published specs.
Is the Onyx ST a mid-drive?
Yes. Mokwheel lists a mid-drive motor rated at 750W, 1000W continuous and 1300W peak, with 210+ Nm of torque.
How heavy is it?
Mokwheel’s spec table says 88 lb, and the comparison chart on the same page says 89 lb.
How fast does it go?
Mokwheel lists 20 mph on the throttle and 28 mph with pedal assist, Class 2/3.
Is there a step-over version?
Yes, the Onyx. On Oct 28, 2026, every Onyx color showed as sold out on Mokwheel’s site.
Pros and cons (from the specs and sources)
Pros: mid-drive with 210+ Nm listed; torque and cadence sensor; full suspension with a 135mm dual-crown fork; four-piston hydraulic brakes; Shimano 10-speed; dropper seatpost; 940Wh battery; 560 lb payload; step-through frame.
Cons: 88 to 89 lb; $3,399.99, almost twice the Obsidian; only Mint Green was in stock on Oct 28, 2026; one frame size; two different weights on the same page.
Who it’s for
On paper, the Onyx ST fits riders who want a step-through fat tire bike with full suspension and a mid-drive for steep, loose ground or hauling gear into the backcountry, and who can handle a bike close to 90 lb. If you mostly ride roads and gravel, a hub-drive fat tire bike like the Obsidian covers a lot of the same ground for much less.
Price
As of Oct 28, 2026, the Mokwheel Onyx ST was $3,399.99, down from a listed $3,599.99. Mint Green was in stock, shipping within 2 business days, while Panda and Desert Camo showed as sold out. The page offered a free full fender with the bike.
“Great is our Lord, and abundant in power; his understanding is beyond measure.” Psalm 147:5 (ESV)
