- A high quality full suspension e-mountain bike that's also a speed pedelec (capable of 28 mph top speeds), solid hydraulic disc brakes, wide thru-axles with Boost Technology
- Adjustable 150 mm RockShox suspension front and rear, four-bar rear swing arm to reduce brake jack, 22 speed drivetrain with Shimano Deore XT Shadow Plus clutch on rear derailleur to reduce bounce and slap
- Integrated LED lights with a bright mode at the rear when brake levers are pulled, room for a bottle cage or other accessory on the downtube, beautifully integrated battery and motor
- A bit heavier than competing FS models due to battery size (37v 17.5ah), not a fan of the spring loaded kickstand, battery port cover doesn't always stay down, battery lock can be wonky and is placed in the path of the left crank arm
The BULLS E-Stream EVO 45 FS combines some of my favorite features of electric bikes. It allows you to travel in full suspension comfort without concern for lost efficiency because it’s electric… and has an extra-large battery pack. It allows you to travel faster, in this case much faster, with advanced pedal assist up to 28 mph in a way that feels natural and blends in. And, it keeps you safe and visible with smart integrated lighting systems. Not only are they sleek and light weight, the rear light has a large reflective surface and gets extra bright when the brakes are activated (as with an automobile). This is one of the most purpose built and stealthy electric mountain bikes I’ve tested in recent years and while the price tag isn’t low, I think it’s reasonable given the limited options in this niche. If you’re someone who commutes by week and could appreciate the speed and lighting features but loves to hit the trails on the weekend and doesn’t want a flexy frame with cheaper suspension and touch points then this is one of your only options. You get an upgraded saddle, grips and capable hydraulic disc brakes (208 mm front rotor and 180 mm rear). The only accessory I felt was missing is a dropper seat post. I love the traditional diamond frame and appreciate how the battery interfaces with the downtube (from the bottom up), keeping it open for hanging on car or bus racks. With the exception of a few European mandated quirks like a spring loaded kickstand and oversized brake levers, this thing is exactly what it should be… and it even has bottle cage bosses. You won’t be distracted by a large display or overly noisy motor and with five frame sizes to choose from, it’s more likely to fit the tall and short riders alike. I had a blast testing this ebike and found myself subconsciously comparing it with the other leaders in the space, it left me a little envious.
Interfacing directly with the core of the frame, completely replacing the bottom bracket, is a 350 watt mid-drive motor from Brose. This thing peaks with 90 Newton meters of torque and can reach 530 watts when climbing in the highest level of assist. The compact black casing hides behind two chainrings and has a nice neoprene pad stuck to the bottom to reduce nicks and scrapes picked up on the trail. While you can definitely hear it operating at the highest levels, especially when pedaling with a higher RPM, it’s one of the quieter geared mid-drive motors I’ve tested. Inside, there’s a collection of gears and a belt transition that takes the edge off and reduces some of the mechanical vibration and sound. When riding on a dirt trail, especially with larger knobby tires, it almost disappears completely. One thing you won’t find here is a shift sensing controller. It measures rear wheel speed, pedal cadence and torque but relies on you to shift consciously while backing off on pedal pressure (I usually ramp up my speed then ease off pedaling to switch smoothly). All in all, this motor is very capable and a lot of fun in the higher levels when paired with the wide range of gears. Brose and Yamaha are two of the only mainstream mid-drive systems offering this right now and while they aren’t quite as responsive as Bosch (winding down more slowly) they work quite well and tend to produce less noise. In short, the motor is great but it’s up to you to operate properly and empower it while avoiding damage to two derailleurs, the chain and sprockets. I believe in you…
Powering the motor and both integrated LED lights is a high capacity Lithium-ion battery pack. Inside are BMZ cells offering 37 volts and 17.5 amp hours of energy… enough to top 100 miles per charge if you’re willing to slow down a bit and use lower assist levels. 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 to 28 mph I’d suggest taking those turns very carefully lest you slide out and whack your chin as I have done on occasion. Wet grass is a big danger… but you may find yourself going from sidewalk to grassy hill to catch air. This bike feels a lot like flying because it can handle almost any terrain comfortably and won’t leave you breathless to maintain higher speeds. 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 bottom and snapping the top). There’s a key and sliding lever thing which lets you unlock the pack. I do wish the keyed locking core was spring loaded and defaulted to locked vs. making you twist the key each time and I was being extra careful not to drop the battery when using the slider lever thing. The pack weighs about seven pounds which isn’t bad, but you’re actively pulling it down out of the downtube and the weight plus gravity plus trying to keep the bike from tipping can make it awkward at times. Thankfully, there’s a kickstand included with this bike (most e-mountain bikes don’t have them) but it’s spring loaded and constantly wants to slap back up. This is due to some European regulations… which also mandate large knob-ended brake levers, reflectors on the suspension fork and a license plate mount. Stepping back from the bike, once the battery is mounted properly, it looks just beautiful. And underneath the battery you’ve got another strip of foam padding to keep it protected. In short, the battery weight is positioned well and the quiet motor plus near-invisible battery result in a more normal looking electric mountain bike, one that won’t turn heads or ruffle feathers.
Operating the EVO 45 FS feels simple because the display panel is very basic and limited. Once the battery is charged and mounted (either charged on or off the bike) you sometimes have to press a power button on top of the downtube to get it to wake up. Next, you press the top edge of the button pad which is mounted within reach distance of the left grip. This brings up a nice display with speed, assist level and battery level readouts. It’s a transflective display, designed for easy reading in light or dark scenarios and it’s unique to Bulls from what I can tell. You click up or down to change power level (filling three boxes for full power) and pedal along, the drive systems kick in automatically from there. It’s very simple and easy to adjust without taking your eyes off the trail and there’s less to get scratched, broken (if you fall) or noticed as being “electric” by fellow riders. On the left side of this display button pad thing is another switch to activate the LED lights and as mentioned earlier, the rear light goes extra bright when braking. I love that they managed to squeeze in a Micro USB port on the display pad (near the base) for those who like to mount portable electronics to their handle bar cockpit area. Back to the go-anwhere speed commuting scenario, you could mount your phone and use GPS for longer rides without completely draining it. Just get the correct adapter off Amazon.
Not everyone cares about speed, full suspension or comfort the way I do. I’m not looking for a motorcycle here but I do enjoy the extra boost when riding in traffic and I only have the space and budget for one ebike. In so many ways, the BULLS E-Stream EVO 45 FS satisfies that vision. An ebike that blends in, is fun to ride and useful in a range of scenarios without being ridiculously expensive. Yes, $5,500 is far from cheap but it’s way less than some of the competing electric bicycles out there with similar designs like the Specialized Turbo. I like that Bulls went with Boost Technology (wider axles) and the sturdy thru-axle design front and rear. That’s a big deal when you’ve got large knobby tires, off-road and high speed. A dropper seat post would be easy to add yourself aftermarket and while I’m not sure where the cable would end up, the original brakes, shifter wires and electronics are all internally routed reducing snags and keeping the bike clean. Depending on how and where you’re riding, note the throttle lever on the rear derailleur which tightens the springs and reduces chain bounce and slap. It also makes shifting harder but is worth experimenting with as you go from streets and trails to bouncy rocks and mountains. The tires are tubeless ready and that’s one way to cut down on the heavier build (this is a 56 lb ebike) and that makes riding with lower PSI possible too… but do check on the pressure regularly given the weight of the bike slowly squeezing air out. 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 sold at a growing number of US dealers that could help you set it up and the two-year warranty is solid. This is a larger company with International distribution and a good reputation, I’d like to thank Bulls for partnering with me to make this review possible. We filmed on an access road in Southern California with some great views and had a blast.
- One of the very few full suspension, higher-end, electric mountain bikes that is also a speed pedelec capable of 28 mph top speed!
- Integrated LED lights front and rear including a bright mode for the rear when you pull the brake levers… this increases safety if you’re using the bike to commute or jog around town during the week
- You get a few little extras from European standardization including a license plat mount at the back, larger brake levers with ball ends and a flick bell
- The battery blends in perfectly with the frame, it’s mounted up into the downtube and has a nice rock guard on the bottom (along with the motor) for protection off-road
- I love that the screws used to attach some plastic housing on top of the downtube (for the battery, charge port and controller) can be used to mount a bottle cage
- While you don’t get as many readouts with the Bulls display panel, I love how compact and easy to use it is, I also like the transflective readout technology which is easy to read in dark or super bright situations
- Built into the display ring is a Micro USB port that could maintain your phone, Garmin or other portable electronic device… it’s conveniently located and blends in
- 22 speed drivetrain with Shimano Deore XT Shadow Plus (has a tightening lever to reduce chain slap), offers plenty of range for climbing or reaching and maintaining higher top speeds… just awesome and perfect for a speed pedelec, I also like the chainring bash guard on it
- I love the adjustable air suspension components here, both from RockShox with 150 mm travel, but would consider adding a dropper seat post for added versatility transitioning from climbing to descending
- You can get the E-Stream EVO 45FS in five frame sizes which is really impressive to me, I’d consider four to be a lot but that makes this bike even more accessible to a range of body types
- Both wheels offer quick release and use thicker longer axles (with Boost technology) for strength and stiffness with the larger tires
- I like that the battery us removable to reduce weight and that the top triangle on the bike is more traditional because it’s much easier to hang from some racks
- Very nice hydraulic disc brakes from Tektro, these are ebike specific (with the light integration) and offer great stopping power with a 203/180 setup vs. just 180 mm rotors on both
- Super-fast 5 Amp charger compared with more standard 2 Amp or 4 Amp, nice to have given the larger capacity… I also like the magnetic EnergyBus plug style that will pop off vs. bending or tipping the bike
- The motor is smooth and quiet, apparently there’s a rubber belt inside transferring power between standard gears and this reduces vibration and abrasion
- The little rubber cover flap meant to protect the charge port from dust and water doesn’t stay put very well, I had to work with it a bit each time which was frustrating
- The locking core on the left side of the downtube is directly in the path of the left crank arm which means it could get snagged or bent easily… be careful not to leave the key in and make sure the battery is fully secure, I believe you have to manually turn again to lock the battery vs. just having it always locked when clicked in
- 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 but the advanced assist makes shifting crunch-free if you just ease off a little and practice
- I was surprised to find out that the bike weighs 56 lbs because many other premium FS ebikes are in the 52 lb range but this one has a larger capacity battery and reinforced top tube so that’s probably what does it
- The kickstand has this automatic spring action that I really dislike… easy enough to remove the stand if you want (I believe this is a requirement for European speed pedelecs but I feel that it’s unstable and bikes tend to tip more with it)