- One of the only full suspension mountain bikes from a premium brand that offers Class 3 high speed performance (28mph, 45km/h), long travel 150mm air suspension supports all mountain riding
- Excellent weight distribution and drive system integration, the motor and battery are virtually hidden in the frame, sturdy 15mm and 12mm thru-axles provide strength for wider Boost hub spacing and plus sized tires that offer traction and stability at speed
- Available in four frame sizes for optimal fit, sloped top tube lowers stand over height, integrated cables stay out of the way, extra large 203mm hydraulic disc brakes support quick smooth stops
- Wide 22-speed drivetrain supports climbing and fast riding, above-average battery capacity extends range, integrated Micro-USB port on the control pad lets you charge accessories, the bike isn't stocked with a seat post dropper, Shimano Deore XT drivetrain with Shadow+ one-way clutch reduces drops and slaps
To run the forums, host the website, and travel, I charge a universal service fee for my reviews. This in-depth review was sponsored by BULLS North America. My goal is to be transparent and unbiased, this video and written review are not meant to be an endorsement of BULLS products.
BULLS updated their E-STREAM EVO 45 product for 2019 and changed the FS to AM, which stands for all mountain. This is a Class 3 speed pedelec e-mountain bike! That’s very unique and rare in the space, because many trails restrict use to Class 1 only, which means 20mph. In my experience, test riding the latest EVO 45 for this review, the top climbing speeds may still hover around 8-10mph. The big difference is in how quickly you’ll be able to ride to the trail on paved streets, or how quickly you can zip through level cross country sections. This electric bicycle can reach ~28mph before the motor cuts out completely. You’ll still have to work, there’s no throttle mode, but it helps you overcome wind resistance and tire drag. Tires on this model come in plus sized 27.5″ x 2.8″ and are supported by sturdy thru-axles with quick release. BULLS has opted for Boost hub spacing, which is slightly wider than traditional, in order to create a sturdier bracing angle for the spokes which increases strength and stiffness. The big differences between this model and the 2017 version include MonkeyLink magnetic wired-in light connections (the kit costs $170) and bottle adapter (the bottle costs $45), an improved charge port cover and locking core position, better protection for the base of the battery and motor casing (rubber vs. foam), sturdier rear suspension design and surround-protection, a more reliable kickstand, and nicer Magura brand hydraulic disc brakes vs. Tektro. Much has remained the same, but the price has increased by $300. Given how unique this offering is, being a high-speed all mountain bike from a leading company with top-end components, I think the price is warranted. It would make an excellent adventure bike for off-highway vehicle (OHV) trails or a great “adventure commuter” allowing you to cut across any type of terrain on your way to work. The Brose drive system is smooth and quiet, the battery offers above-average capacity, and BULLS has a great reputation with dealers and service centers all around the world. I really like the color scheme updates, and little extras including a Micro-USB charging port built into the BLOKS display panel clamp. While the older model came stock with integrated lights, a bell, and larger brake levers based on European requirements, the 2019 model is specced for the North America market with more customization and mountain-specefic features. It’s nice to be able to remove the MonkeyLink lights… or simply not buy them. With the stability and comfort of wider tires, this product feels stable and under control at higher speeds, and the 22 gear combinations provide plenty of comfortable cadence options. I’m usually not a fan of multiple chainrings, but BULLS has specced higher-end Shimano Deore XT for both and added a sturdy alloy bash guard. When you look at this product from the side, notice how compact and hidden the motor is, and how beautifully the battery integrates. The only hardware upgrade I would like to see added, or would consider adding aftermarket, is a seat post dropper. This would make transitioning through different types of terrain a bit easier because you wouldn’t have to stop and lower the saddle for descents and other sketch off-road section.
Driving this ebike is a 250 to 530 watt Brose mid drive called the TF (which stands for trekking, fast). It’s capable of producing up to 90 newton meters of torque, which is very capable for climbing as you shift through lower gears. The casing is compact, but sturdy, and the motor produces much less noise than competing products I’ve tested. This is because it utilizes a Gates Carbon belt drive between the planetary geared motor and the driveshaft spindle. When riding on a dirt trail, especially with larger knobby tires, it almost disappears completely. This adds to the visual stealthiness mentioned earlier. One thing you won’t find here is shift detection. The motor controller measures rear wheel speed, pedal cadence and pedal torque, but relies on you to shift thoughtfully in order to reduce grinding and mashing. You can do this by backing off a bit as you click through gears. It’s a more advanced drivetrain in some ways, but extremely quick, natural, and fluid. Since the motor interfaces with traditionally sized chainrings, and there’s no reduction gearing in between, you won’t experience pedal drag when the ebike systems are off of you’re striving to top the maximum 28mph top speed.
Powering the motor, two MonkeyLink light mounts, and 5 volt Micro-USB port on the control pad is a high capacity Lithium-ion battery pack. Inside are 18650 BMZ branded cells offering 37 volts and 17.5 amp hours of energy, which is quite a lot! Approximately 50% more than the average 500 watt hours I see from most competitors this generation. Note that anytime you’re riding above 20mph, air resistance produces drag exponentially. People aren’t super aerodynamic when sitting up straight, riding on a bulky mountain bike frame with wide knobby tires. And, on those occasions where you throw efficiency to the wind and max out at 28mph, I’d suggest taking those turns very carefully lest you slide out and whack your chin as I have done while joy riding across wet grass on my way to work. This e-bike feels a lot like flying because it can handle almost any terrain comfortably, and won’t leave you breathless to maintain higher speeds. It’s a blast! Back to the battery itself, the mounting interface is solid but a little tricky to work with. You have to push the pack up from beneath the downtube (latching the top and snapping in the bottom). There used to be a sliding lever system that was tricky to deal with, but now it’s just a click-in system… During removal, it’s nice to have a kickstand on the bike, so you can use both free hands to unlock the pack and carefully lower it out. Unlike Bosch, which has a two-step design for their integrated PowerTube battery, the BULLS BMZ battery can tumble out unexpectedly when unlocked from above. It’s alright to never take the battery off of your bike, but that makes it heavier to lift, service, transport on car racks, and could expose the pack to extreme temperatures at outdoor racks or inside uninsulated garages and sheds. Lithium-ion batteries can be temperature sensitive, so it’s best to store them in a cool dry location to maximize lifespan. And, if you know that you won’t be riding for a month or more, try to leave it at 50% capacity so as not to stress the cells. Charging back up will be quick with this electric bike, because BMZ has supplied a faster five amp charger vs. the standard two amp that come with most competitors. Bosch has a really nice four amp charger that’s a bit slower but much lighter and physically smaller. I prefer the Bosch charger to this bulky aluminum charger… but suppose that this might be stronger in the long run? It interfaces with the battery with a magnetic plug that is designed to pop out vs. breaking if you trip on it accidentally. It’s called EnergyBus and uses the Rosenberger standard, which is pretty great and usually only found on nicer products. The pack weighs about seven pounds which isn’t too bat given the size, but it’s a bit long and doesn’t have a handle built in, so be careful. When you take a step back, it’s easy to appreciate how hidden the pack is, how well the new rubberized guard protects it (note that the electronics are also IP56 ingress rated against dust and water), and how perfectly weight is positioned (center and super low for optimal balance and handling).
Operating the BULLS E-STREAM EVO 45 AM feels simple because the display panel is compact and the main buttons are so intuitive. Once the battery is charged and mounted, you may begin by pressing the power button on top of the battery pack or on the top edge of the BLOKS control pad, which is located within reach of the left grip. This wakes it up, and shows your current speed in the middle, a battery bar infographic with five squares below, assist level with up to four full blocks above, and an up and down arrow with plus and minus symbols inside. To raise or lower motor support, you press onto the upper or lower half of the display itself. This fills in the blocks (which go from empty to four full) and that’s how you know what power level you’re riding in. Now, the readouts are off-white in color with the background being black. The readouts are fairly easy to see in bright light because the LCD is transflective. When you click in, the display will also become backlit for a moment, so it’s easy to see in dark riding conditions as well. The BLOKS display panel is definitely on the smaller side compared to Bosch, Yamaha, and Shimano. You don’t get any feedback about average speed, max speed, trip distance, or even odometer. The five 20% battery bars are much less precise than a full one-percentage increment readout and there’s no dynamic range estimator. Still, the smaller physical size leaves more cockpit space for mounting a phone or Garmin device… and you can charge or maintain on the go by connecting to the Micro-USB port just below the display. Going back to the quiet motor and hidden battery design, perhaps this display will go unnoticed by fellow riders or be less provocative at the bike rack. You cannot easily remove it, nor can you swivel it once it’s tightened down. On the left edge of the control pad there’s also a walk mode button (which is useful if you get a flat or encounter a steep gnarly section of trail), along with a lights button. You can hold the lights button in for several seconds and then click up or down on the main screen to change units from miles to kilometers and back. Note that the light button is only really relevant if you purchase the aftermarket MonkeyLink compatible lights. And on that note, the rear light interface could also be used for a compatible fender. One final consideration about the headlight is that it is not aim-able. It cannot be positioned up or down, it just points ahead based on the head tube angle and stem angle of the bike itself… which is a bit up for this bike due to the longer travel fork. it does, however, point from side to side as you steer the bike.
Not everyone needs the additional speed or gears on offer here, on many mountain bike trails it’s technically not even allowed, but the E-STREAM EVO 45 AM does a great job creating a unique and fun experience. Whether you’re commuting, riding on private land, or exploring OHV trails, it’s capable and durable. Yes, this product will also weigh more and cost more than some of its Class 1 competitors, but the high-capacity battery is part of what makes it so capable and special. I see and appreciate the many ways that BULLS has improved this product over the past year, and am getting good feedback from their dealer network. The North America leadership team is proactive and supportive to them, which means good customer service for you. They are one of the first brands to approach me about reviews and they have invested a lot into shows like Interbike and demo ride events throughout the year. The tires on this bike are tubeless ready, and that’s one way to cut down on the heavier build. Some people might want to explore a single sprocket up front given the 11 speed cluster in the rear (for even more weight savings and simplicity). BULLS is a larger company with international distribution and a good reputation, I welcome real-world feedback in the comment section below and invite you to connect with others to share more in the Bulls electric bike forums as well.
- Brose motors tend to be very smooth and quiet, especially the T and TF (which this ebike uses), there’s a Gates Carbon belt drive inside that reduces vibration by transferring between a planetary geared motor and the spindle for output
- Both the motor and battery pack are hidden within the downtube and bottom bracket, this is one of the stealthiest electric mountain bikes on the market right now
- BULLS did an excellent job matching accessories with this ebike, the dark frame color blends perfectly with shifter cables, brake lines, the suspension fork, hubs, spokes, and rims
- The bike is available in four frame sizes to maximize fit and rider control, notice the angled top tube which lowers standover height (important if you have to jump off on an angled slope)
- Both wheels offer quick release for easy trail maintenance, the connect with sturdy thru-axles that support wider boost hub spacing and the large 2.8″ plus sized tires
- With longer 150mm suspension travel, this ebike offers all-mountain performance including climbs and descents, the larger tires provide increased traction, stability, and comfort while reducing deflection
- Extra large 203mm hydraulic disc brakes with quad piston calipers provide the necessary stopping power for higher speeds, steep descents, and increased weight
- Higher speeds tend to sap batteries quicker (wind resistance becomes a factor above 20mph) so it’s great that BULLS has included a custom ~650 watt hour battery, it’s significantly larger than the average 500 watt hour packs from other ebikes right now
- I think it’s neat that they included long plastic slap guard and an adjustable kickstand, the stand may bounce around and rattle on the trail but really comes in handy if you commute and park the bike at public racks or in your garage
- As with many other BULLS mountain bike products for this season, it’s cool that this one comes with MonkeyLink light/fender magnetic mounting points, they would be especially useful for commuting or riding to and from trails in morning/evening conditions
- I love that the downtube has bottle cage bosses, BULLS includes a magnetic MonkeyLink bottle mount preinstalled, but you must purchase the $45 bottle separately
- The BLOKS display panel is compact but easy to read in bright conditions because it’s transflective but also backlit for dark conditions, there’s a Micro-USB port built into the bottom for charging accessories
- The rims and tires are tubeless ready, which allows you to reduce weight and run lower pressure without pinch flats, I like Schwalbe tires and noticed that these ones have ADDIX speed grip for higher speed riding
- The drivetrain appears to be well protected against rock strikes and drops because the chainring has a large alloy guard, the front derailleur functions as a chain guide, and the rear derailleur has Shadow+ a one way clutch to reduce slaps and bouncing (just click the little gray leverl into the up position to enable or click down for easier shifting and wheel removal)
- With the 11 speed cassette and 2 speed chainring setup, you get plenty of pedal options for climbing and urban conditions
- The new generation of E-STREAM models have a tough rubberized shield along the base of the battery and front of the motor casing, older ones had a narrower foam shield that didn’t seem as durable
- On the one hand, I really appreciate how fast the battery charger is (5 amps vs. 2 amps on most competitors) because this ebike comes with a high capacity battery, and I like the quick-release magnetic charging cord… but on the other hand, the charger case is larger and heavier than average and will take up more space in your backpack
- The motor starts and stops very quickly and can support 120+ RPM pedaling so it doesn’t feel like you lose power when downshifting into a hill climb, it responds a bit more to torque which feels natural and empowering but can surge a bit with each stroke compared to Bosch
- I like that the battery is locking for security (and using premium ABUS cores and keys) and that it’s removable to reduce weight if you’re mounting the bike on a car rack, since the bike only comes in high-step diamond style there’s plenty of space to hang from most car racks without a crossbar adapter, if that’s what you’ve got vs. a platform rack
- I feel like this electric bike would be a good candidate for a seat post dropper, it’s the one upgrade I didn’t see but you could always get one aftermarket
- Some of this is personal preference, but I really don’t love the curved saddle or cage style pedals stocked here, the Ergon ergonomic grips are great though
- The display panel doesn’t list as readouts, isn’t as large as most competitors, and isn’t removable… but it still works well for this type of application
- I like the MonkeyLink concept, being able to add and remove lights that will run off of the main ebike battery easily, but the price of the lights ($170 for a front and rear light) just seems high
- The positioning of the headlight is good in many ways, it’s up high, points where you steer, and is sprung vs. a lot of suspension fork arch mounted lights I see that can bounce around, but you cannot aim it up and down… it’s set in one position based on the head tube and stem angle
- As fun as it is to ride at ~28mph on flats, my experience is that this drive system climbs about the same as the standard Class 1 Brose T, S, and S Mag, and since it’s a Class 3 speed pedelec, it’s not going to be legal on as many mountain bike trails where 20mph is the limit
- Unlike the Bosch PowerTube, which has a two-step battery removal process, this custom BULLS + BMZ battery pack sort of just tumbles out as you unlock it… so be careful to stabilize the bike and support the pack when unlocking, also keep track of the magnetized battery charging port cover because it doesn’t have a leash and could be easily set down and lost
- Unlike Bosch and some of the nicer Yamaha display panels, this setup lacks a range estimator and battery percentage readout which makes it difficult to gauge distance at times, you just have a five bar battery info-graphic
- No shift sensing technology with the Brose motor controller (only Bosch really offers this right now), but the advanced multi-sensor assist makes shifting smooth if you just ease off of the pedal pressure a bit while shifting
- I was surprised to find out that the bike weighs 56 lbs because many other premium FS ebikes are in the 52-54 lb range, but this one does have that higher capacity battery, thru-axles, and plus sized tires