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Bulls E-Stream EVO AM e-MTBs horn up Brose S-MAG motor w/monster power reserve

2021 bulls e-stream evo am emtb 27.5+ full suspension ebike
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The 2021 Bulls E-Stream EVO AM e-MTBs are charging to the trail heads with an updated Brose S-MAG motor packing a massive downtube-integrated 750Wh battery. Now in their 6th generation, you can expect a large power output and long range from these new full suspension e-bikes. No geometry updates for this model year but Bulls have added a frame size at the smaller end to make this high capacity e-bike more accessible. 

Bulls E-Stream EVO AM

The 2021 Bulls E-Stream EVO AM is a full suspension e-MTB packing a high torque motor and high capacity integrated battery. The aluminium frame boasts 150mm of rear wheel travel paired with a 150mm fork. That travel places it firmly in the all-mountain category, as does its conservative geometry.

2021 bulls e-stream evo am 4 black frame
The 2021 E-Stream retains the integrated look with downtube hidden 750 Wh battery and seat tube integrated rear shock

Angles on the E-Stream aren’t overly aggressive by any means, with a 67.5° head angle and 74° seat tube angle. Reach is conservative too, spanning a 421mm to 465mm range over the four frame sizes. Chainstays are long at 460mm, ensuring ample clearance for 27.5+ tires. 

Notable updates for the E-Stream EVO AM include 12 speed drivetrains and 4 piston brakes with 203mm rotors front and rear across the three model range. All are also fitted with the new Brose S-MAG motor… 

Frame Height 41 cm 44 cm 49 cm 54 cm
Seat tube length 410 mm 440 mm 490 mm 540 mm
Head Tube 110 mm 110 mm 125 mm 140 mm
Wheelbase 1177.0 mm 1191.0 mm 1212.0 mm 1233.0 mm
Chain strut 460 mm 460 mm 460 mm 460 mm
Crank Offset 7 mm 7 mm 7 mm 7 mm
Reach 421 mm 435 mm 450 mm 465 mm
Stack 590 mm 590 mm 603 mm 618 mm
Seating angle 74.0° 74.0° 74.0° 74.0°
Steering angle 67.5° 67.5° 67.5° 67.5°


Updated Brose S-Mag Motor

The Brose S-MAG (magnesium) is their highest performance e-MTB motor. It boasts a maximum torque of 90 Nm, offering 410% maximum pedal assist. The main update to the the Brose S-MAG motor seen on the 2021 Bulls e-MTBs is the firmware upgrade which is said to optimize performance and smooths out power delivery.

2021 brose s-mag ebike motor on bulls e-stream evo am e-mtb

Pricing & Availability

The 2021 Bulls E-Stream EVO AM is available at three price points. The top-end AM 4 gets a FOX Float 36 Rythm Grip fork, Shimano XT drivetrain and 4 pot SLX brakes with Bulls own Eccentric 35mm wheelset.

The AM 3 and 4 are available now at $5799 and $6299, respectively. The budget option AM 2 expected in Spring 2021 is anticipated to be priced at $5399. 


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3 years ago

I can’t understand that we have XXI century and Bulls is still making bikes with terribly long seat tube.
54 cm in Extra Large frame?!

3 years ago

Horn up isn’t the greatest choice of words?

3 years ago

I had to read the title three times, and I’m still not sure it’s in English.

3 years ago

Just buy an electric MX bike, go have your motorized off-road fun, and be done with it.

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