- A fatty electric bike with medium sized 3.25" tires, strikes a balance between cushion, traction and handling
- Powerful BionX D-Series motor offers good torque and higher top speeds ~28 mph in pedal assist mode
- Available in four frame sizes, custom hydro formed tubing with expanded yoke to accommodate larger tires, 15 mm thru-axle and tapered head tube for added strength, compatible with Schwalbe Super Moto tires
The OHM Sport XS750 Plus is one of the first electric bikes I’ve tried with the new 27.5″ x 3.25″ fat tires. They strike a balance between increased cushion and surface area (great for soft terrain like sand and snow) and narrow, nimble handling. To me, they look sleek and clean compared with the chunky 4″ fat tires and that look is complimented by the tight drivetrain and disc brake design. This is a polished ebike with several upgrade options that change ride quality (an optional Suntour Raidon air fork or NCX suspension seat post) or add utility (sturdy bosses at the rear for a carry rack). OHM is a Canadian company that has been around since 2005 designing custom bike frames that are purpose-built to work with the BionX drive system. What you get here is a well balanced, clean design in four sizes with an excellent warranty (three years on the electronics and five on the frame). I had a blast with the XS750 Plus and was surprised how light it was (just 50 lbs) considering burly look and impressive battery capacity. If you like the look of fat tire bikes but want something a bit more streamlined then this could be a great option. I love that the rims are compatible with the Schwalbe Super Moto city tires because they tend to increase range and reduce noise for commuting but I know I’d still want to take this thing out to the trail on the weekend. While it’s not as powerful from standstill as a mid-drive bike like the Haibike Fatsix it’s capable of going a lot faster in pedal assist mode and it costs quite a bit less at ~$4k. It’s a quiet bike but the larger hub lets people know that “something is different”. I like that it offers throttle mode in addition to assist and that you can override assist and hit 20 without it cutting out.
Driving the XS750 Plus electric bike is a unique gearless, direct drive hub motor produced by BionX. It’s their top of the line D-Series 500 watt design with an extra wide build for improved climbing power. It’s actually lighter than the smaller P-Series even though it’s significantly more powerful offering 50 Newton meters of torque. At ~8.8 lbs it’s still not “light” compared to an internally geared hub motor but that’s because it uses large magnets to produce power instead of gears. The end result is a product that’s more durable and capable of regenerative braking but also not as efficient for coasting. This motor (as with most of the gearless hubs I test) doesn’t freewheel and you experience a tiny bit of drag due to cogging (the magnets inside repel the stater). In practice, it’s not something I notice much, especially with the larger wheels that tend to carry momentum, but I feel compelled to highlight the difference. Ultimately, I appreciate this innovative design and like that they matched the plastic shell to the spokes and rim (all in black). The torque sensor for pedal assist is built right into the hub which keeps it protected and might also make maintenance easier. The rear end of the bike is fairly standard with a 135 mm drop out width and a cassette that slides onto a spline meaning you could replace it more easily. If you need to do maintenance on the rear wheel or swap the tires there are two quick connectors for power and they are both well positioned under the left chain stay. I feel like they are mounted out of the way and overall the rear end of the bike is narrow and sleek (especially for a fat bike).
Powering the motor and display is a powerful Lithium-ion battery pack with high quality Samsung cells. It fits neatly and securely onto the downtube keeping weight low and centered on the frame. Unlike most aftermarket conversions with BionX, or other e-bike kits, the mounting rail on the OHM Urban XS750 Plus uses three bolts for added durability. This is great to see on an off-road e-bike bike and other parts are overbuilt as well (oversized tapered head tube and 15 mm thru-axle on the front wheel). This thing handles well on packed trails, grass, gravel and snow and you can adjust the air pressure according to the terrain (lower for soft terrain to increase surface patch and grip). So the battery pack locks to the mounting bracket securely and has a flip-up lever on top making it easy to carry around. I like the design and appreciate that they matched the black color to the frame, this is a purpose built electric bike and even though it’s using a third party battery and motor system they look great together. I also appreciate the internally routed power cables because they don’t get snagged as easily. Inside the pack are 18650 Samsung cells offering 48 volts of power and 11.6 amp hours of capacity which is pretty great (especially if you use regen). If you want to maximize range, I suggest using one of the two lower levels of assist and you can extend the life of the pack by storing it in a cool dry location at a 20% to 80% charge level. Check on it every few months and top it off if you haven’t used it.
One of my favorite parts about the BionX electric bike system is the user interface. Once the battery pack is charged and seated properly you can activate the bike by pressing the top left or right button on the display pad. You’ll see a speed and battery level readout but most of the screen is used for assist levels. There are four bars on the left (denoting regeneration level) and four bars on the right (denoting assist level). It’s super intuitive and easy to read… the remote button pad near the right grip makes changing levels easy and safe, it even has a tactile clicking sound that you can feel through riding gloves. You don’t have to take your hand off the grip to interact with the drive system on this bike and you can override assist with the variable speed throttle at any time. I tend to ride in lower levels of assist for exercise and efficiency then jump in with the throttle to scale hills or pass people. The only caveat to the throttle system is that the bike must be rolling ~2 mph before it can activate, this is a safety feature designed to reduce accidents. On that note, I recommend always turning the system off (by pressing the power button) before removing the battery or loading the bike onto a car/bus/train. Given the larger knobby wheels, this bike might not coast as smoothly or efficiently and the range will suffer a bit as a result. I like the charger that’s included because it’s small and light weight ~1.5 lbs so you can easily bring it along for a quick top-off. There’s a 10 minute timer built into the bicycle controller so it automatically powers down if you forget. I love that the display panel is removable, the mount for it swivels to reduce glare and that there’s an integrated brake lever motor cutoff + regen! OHM even sells replacement mounting brackets and displays so if you crash on the trail you can fix it yourself fairly inexpensively.
Having reviewed the OHM Sport XS750 15 and now Plus model this I definitely enjoyed the larger wheels. They’re just fun… and the frame is custom engineered to work with them (the chain stays are much wider and use a yoke for added strength vs. bent tubing). The BionX system is unique and really easy to appreciate here even if it’s a bit different looking. I’m still just so impressed with the weight and how easily the battery, display and front wheel come off. It was easy to get to the trail and I found handling to be quicker than some other fat ebikes I’ve tried. To me this bike seems very well priced and I love the upgrades, the fact that it has throttle mode is huge and it’s all just so well connected and integrated software+hardware. I had never really considered buying a fat bike before but this one got me thinking… it does snow sometimes where I live and this would be a blast to cruise around on. When the summer months come it would be easy to swap tires to the slicks and almost be back to a regular bike :)
- Includes bosses for adding a rear rack, this could be especially useful if you want to commute with the bike or go for adventure camping rides
- The design emphasizes off-road performance with a smaller 36 tooth chainring, plastic guide and short cage derailleur to reduce chain bounce
- Impressive climbing performance (for a hub motor) and higher top speed ~28 mph in the highest level of pedal assist, this is the only fat bike I’ve seen to date that’s capable of these higher speeds
- The battery mounting bracket uses three bolts instead of just two, this adds extra strength and is great for bumpier off-road riding
- At ~50 lbs this is a fairly light build considering it uses the larger 3.25″ fat tires, if you switch from solid fork to suspension it adds ~2 lbs
- The rims are compatible with Schwalbe Super Moto 27.5″ x 2.4″ fat city tires, they roll quieter and are more efficient
- High quality wheels and tires, at 27.5″ x 3.25″ you get some of the advantages of 4″ fat tires (made for snow and sand) but they weigh less and are more maneuverable
- The battery pack and display panel are both removable which makes the bike lighter during transport and also deters wear and theft when parked outside or in public spaces
- The display panel is backlit for use in limited light and symmetrical so people who are left or right handed can interact with it more comfortably, it also swivels front to back to reduce glare
- I really like how intuitive the display panel is on the BionX system, you’ve got four regen modes, four assist modes and a throttle that works at all times and offers variable speed output, it’s clean and intuitive
- Available in four frame sizes for improved fit, the sloped top tube is nice when standing over the frame but is still very strong and stiff like a traditional diamond
- If you deflate the tires a bit they add some cushion (I was riding at ~15 PSI in the video) but you can also upgrade to a suspension fork for $200 and add a seat post shock for ~$140
- Quality drivetrain, SRAM X9 with 10 cogs, shifts quickly and smoothly, offers a good range for climbing or riding at higher speeds
- The hollow spindle saves weight, outboard bearings create stiffness in power transfer while pedaling and the chainring has a plastic guide to keep the chain on track when you hit really bumpy terrain, it might also scrape mud off to reduce chain suck
- Pedal assist is activated through a torque sensor which means it is very smooth and responsive, this also means you need to push a bit more and pedal actively to get it working in lower assist levels
- The bike easily accelerates to 20 mph in throttle mode but then cuts out kind of abruptly, it would be nice if it eased off more smoothly… you can go faster than 20 if you’re pedaling along
- The gearless motor is heavier than a geared equivalent and makes the bike more back-heavy (especially with the rack), the mid-mount battery helps even it out
- The motor casing is fairly large and obvious, it doesn’t hide behind the cassette and disc brake rotor as well as some of the smaller geared designs and can catch more crosswind
- Because the motor is gearless and direct drive there is some cogging drag that reduces coasting efficiency, thankfully regen helps to recapture some of this energy at ~15% efficiency
- For safety, the BionX kit is designed to limit throttle use until the bike is moving ~2 mph, this isn’t exactly a con but I wanted to mention it