OHM XS 750 Review

by Brian Mullin on April 14, 2011

I have been riding the OHM XS 750 Electric bike, through most of the Winter, doing short commutes into work, and riding with the family on singletrack, and sundry trails. The XS 750 is quite a high tech piece of engineering, with excellent features and component selection, and it’s more than meets the eye. The Electric duties are performed by a proprietary Li-Mn battery, which powers a BionX 350 watt motor, and a trick BionX LCD command console controls the operational needs. The e-bike’s operation is quiet and smooth, making for an enjoyable riding experience.

OHM XS 750
The company is named after Georg Simon Ohm, a German physicist, who came up with Ohm’s law. Ohms’s law, in a nutshell, is that the current in a circuit is directly proportional to the applied voltage and inversely proportional to the resistance of the circuit (I=E/R or current in amps=voltage in volts/resistance in ohms).

The XS 750 is an Electric sport bike and is meant for commuting, cruising and mountain biking. The bike uses a custom made 7005 aluminum frame that is available in two sizes (18.5 and 20 inches) and two colors (red and black), and comes with a plethora of functional and useful components. The main portions of their e-bike technology are the Command Console, the Bike Motor and the Battery Pack.

Command Console
The Command Console (BionX G2 Console), is sort of like the e-bike’s brains, and it has a multi-functional display much like a normal bike computer. It displays the speed and battery charge level, along with either the distance, odometer, chronometer or average speed, which is chosen with the Crono button. It shows the level of Assistance (motor assist) or Generation (resistance) on the bar graph, which are set by using a combination of the increase (+A) and decrease (-G) buttons. You can arm an anti-theft alarm from the console, so that if the bike is moved a 1/4 wheel turn, it emits a loud noise, and puts itself into a level 4 resistive mode (maximum). There is a Throttle button system, which can do the increase and decrease assistance and generative settings (same as the console), and in addition, pressing the red throttle button itself bypasses any assistance level setting and provides maximum power, much like a scooter. The LCD screen’s backlight can be adjusted for either day or night usage.

Bike Motor and the Battery Pack
The bike uses the BionX 350 Watt electric bike motor (BionX 350HT L Power Series), which is a brushless DC motor (BLDC) that provides 9/40 Nm or 6.6/29 lb-ft of torque, and weighs in a 4.7 kg or 10.4 lbs. It’s a regenerative motor, and by either activating the brake lever (like on a steep downhill) or using the Generative mode in any of its 4 resistive levels, the motor transforms your momentum into energy, and stores it back into the battery, meaning it recharges on the fly. The motor is intelligent, and uses a torque sensor to measure your pedaling force, and then automatically provides assistance proportional to your effort.

Their proprietary battery is a rechargeable Lithium Manganese (Li-Mn), which provides 37V 9.6ah of power, and weighs in at 4kg or 8.8 lbs (measured at 8.95 lbs). It can ride up to 56 miles on a single charge, and can do a fast 20 minute charge to 90% capacity, and a full charge in 3 hours. It has a lockable quick-connect system, so that it can be removed for charging (at home or office). It comes with a Li-Ion battery charger, that plugs into a port on the top of the pack.

Parts Spec
The XS 750 comes with a pretty nice accompaniment of parts, and is well suited for commuting and moderate mountain biking. It uses a Shimano Deore XT drivetrain (3×9), with cranks (3 chainring’s and chain guard), cassette, chain, front and rear derailer and shifters. Braking is provided by the excellent Magura Louise system, with a 180/180 rotor combination, and the larger rear rotor size is for regeneration purposes. Front suspension is the Magura Menja fork with 85mm of travel, and the rear is softened by a Suntour suspension seatpost, with a Velo saddle. The steering system is Ritchey setup, and includes a stem, handlebar and headset. The wheelset is the Mavic 317, and is accompanied by the Schwalbe Marathon Plus tires, and everything is nicely covered by some polycarbonate front and rear fenders. For evening rides, it has front and rear Busch & Müller lights, which are powered by a Shimano Dynamo Front Hub (6V -3W). Last but not least is a kickstand, a rack, and flat pedals.

Impressions
The bike frame is well built, and has a ladies’ cruiser style geometry, and uses a monstrous oversized downtube. The frame is quite burly and stout, which is a good thing, since with the accompanying battery pack and motor, the bike weighs a hefty 57.5 lbs. The battery pack sits cradled down in the middle pocket of the frame, providing a low center of gravity and good balance, which enhances maneuverability, and in addition it gives easier egress when tossing a leg over the top tube (or is that a bottom tube?). The bike has a decent ride for such a heavy monster, and when taking it off the beaten path, the fork and suspended seatpost take the edge off things. The suspension seatpost felt a bit odd at first, especially in direct comparison to a normal shock setup, but I eventually got used to it.

The bike is pretty fun to ride, after you get used to the upright position and its accompanying steering (which feels pretty quick), and the entire packages behemoth weight. The Command Console allows you to set the amount of assistance that the motor will provide, or you can set it to be in a resistive mode so that you are regenerating the battery and/or getting some massive exercise. It has four levels in either direction (assistive or resistive), all dependent on the usage or punishment you require. There is also a red Throttle button, which takes over everything completely (if one is so inclined), meaning you can almost stop pedaling, and the bike flies along like a scooter. Using the throttle or full motor power gives a maximum speed of approximately 20mph, which is a federally mandated limit. That red button is a darn hoot, and highly functional, and it was my favorite feature on the bike. Even with the additional assistance, on extremely steep grades you will have to mash the pedals hard to keep things going. The bike is surprisingly quiet, and the motor provides a very seamless feel, and gives a nice smooth ride.

I used the bike often on my commute’s into work, which during the winter meant dealing with darkness. While the dynamo lights are functional, and quite nice on some rides, they just didn’t have enough spunk for my taste (or is that spark?), so I supplemented things with a helmet and handlebar/seatpost light setup. It gave additional light to make it easier to see and be seen. I would have preferred an integrated light system that operates off the battery instead (of course what if it goes dead?), as it would be more functional, and not drain much power, and would save the slight drag of energy that the dynamo extracts. The rear rack was quite handy, and I frequently would attach a small bag or package when I would go down to the store or work. The path that I take to my office has a combination of paved roads, sidewalks and a short section of an unmaintained gravel trail. I got to test the suspension (front and seatpost) quite well when I was flying down hill through this stuff, and although the tires weren’t the best for deeper gravel, they did a decent job, and I could hold a line with the bike. The low center of gravity and heavy weight did make the bike surprisingly stable at speed through the gnar that I occasionally tossed it into. The fenders were highly functional in the rain and snow, so debris and junk didn’t fly up at me, and it was especially nice when wearing normal clothes (non bike), and it lessened the need to wear rain and/or exotic foul weather gear.

I took it on some longer jaunts from my house up to Monument on the Santa Fe trail (gravel path), for a round trip of 25 miles or so. I really enjoyed all the benefits of the system, as I could use the pedal assist on the climbs and long flats, and adjusts the level depending on the effort needed to maintain the same speed. On the return portion, I used the generative mode on the downhills to power up the battery.

What I really like about this bike, was that I could ride into work or back home in my normal clothes, and not feel like I sweated to death. It was especially welcome on the way home, where most of my climbing occurs, and I frequently used the throttle to assist on the uber steep hills, and one of the assistance levels for some help on other portions of the ride. I get my major exercise elsewhere, so it was a nice tool to get into work, with the added benefit of not perspiring in my everyday clothes. If you wanted, you could vary the resistance, and make it more difficult, and the higher generation levels will certainly give you a good workout, and in addition it charges back to the battery, as does braking on a steep downhill. Regardless of whether you use an assistive or resistive setting, the bike is just darn fun to ride, and the low center of gravity, nice balance and comfortable seating position, and great part selection, make it a joy to use. My Wife rode it around, and was surprised how it felt. The assist mode makes it feel like the bike sort of flies out from underneath you while pedaling, and especially when increasing the assistance level to the maximum, Mach 4!

I took it to a local trail system (Fox Run) with my kids, and my daughter rode her bike, and I hooked up the WeeHoo i-Go recumbent kid trailer, and loaded up my son and hauled him around. I really appreciated the assistance and the throttle button, since some of the hills had loose deep gravel, and were wickedly steep. Without the help, I wouldn’t have been able to get up some of the hills, due to the weight of the bike, trailer and child, and of course the lack of pedaling input from my Son. My daughter got mad when I kicked in the After Burners with the throttle button, and I left her far behind, but it was a hoot to do that, but it does suck up and drain the battery quickly. I got used to Mr. Big Red Throttle, and he was a close and personal friend. The bike does pretty well on mellow singletrack, but when tossed into anything remotely rugged or ugly, it shows some weakness, though the bike wasn’t designed for this functionality (I did test it).

Recharging the battery was very easy, just plug the charger’s power cord into the wall socket, and the other end goes into the battery’s charger port. If needed at work or home, you can detach the battery, and bring it inside to charge. The battery has a pretty decent life, and I rarely drained it (short commute), although pressing the throttle with my happy finger can suck it dry pretty quickly. For the average usage, the charging time is sort of insignificant, and with the approximate 56 mile range, it might not need to be done after every ride.

Bottom Line
The OHM XS 750 is a high quality electric bike with many features, and has a well built and sturdy frame, and a plethora of great components. It can be ridden on and off road (nothing too rugged), and its trail prowess is greatly aided by a suspension fork and seatpost. The bike is easy to ride, and the comfortable upright position, low center of gravity and good balance, make for a pleasant usage. It uses the excellent and intelligent BionX 350W motor, their long life 37V 9.6ah Lithium Manganese battery, and the intuitive BionX control console for operational needs. It has 4 different assist levels for pedaling help, and 4 regenerate levels for training or just battery recharging, and rear brake also does the latter. The motor is quiet and smooth, and the pedaling assistance makes one feel like someone is pushing you along, and makes the bike fly along. Recharging is easy, and the detachable battery allowed it to be brought into the office or home for that purpose.

My favorite feature on the bike was the throttle button, which greatly helped on steep hills, or when I felt lazy. The bike is expensive, and it’s quite a hefty package at almost 60 lbs.

The OHM XS 750 is an amazing e-bike, and for commuting, family outings, and leisure outdoor adventures, this is a great purposeful built entity.

Strengths

  • Throttle button
  • Command console
  • Battery
  • BionX 350 Watt motor
  • Well equipped
  • Low center of gravity and well balanced
  • Easy step over

Weaknesses

  • Expensive
  • Heavy
  • Unwieldy

MSRP: $3799

OHM XS 750 Specs

Power system
Motor BionX 350W (250W HT EU only)
Battery Li-Mn 37V 10Ah / 355Wh
Charger Bionx
Console Bionx
Frameset
Sizes 18.5-inch, 20-inch
Frame OHM Aluminum 7005
Fork Magura MENJA MM85XC
Wheels
Wheel MAVIC XM317 DISC
Tire 26x 2.00″ SCHWABLE MARATHON PLUS TOUR
Hub Shimano DYNAMO
Drive train
Speeds 27
Shifters Shimano Deore XT
Front Derailleur Shimano Deore XT
Rear Derailleur Shimano Deore XT
Crank set Shimano Deore XT
Pedals Wellgo
Components
Seat Velo
Seat post Suntour Suspension
Handlebar Ritchey Riser
Headset Ritchey Pro Logic
Stem Ritchey OE Adjustable
Brake Magura LOUISE Hydraulic Disc
Standard accessories
Lights Busch & Muller IQ
Fender All-weather polycarbonate
Rear carry rack Topeak Explorer
Chain guard Shimano
Kickstand Pletscher Zoom
Warranty
2 year on frame and motor 1 year on components

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