2020 BULLS E-STREAM EVO AM 4 27.5+ Review


Technical Specs & Ratings





Class 1


Full Suspension



Hydraulic Disc



750 Wh

750 Wh

56.5 lbs / 25.65 kgs



Frame Details

6061 Aluminium Alloy


Full Suspension


Fox Float DPS Air Suspension, 150 mm Travel, Compression Adjust (3 Position), Rebound Adjust, Boost 148 mm Hub Spacing, 12 mm Thru-Axle with Quick Release

Fox Rhythm 36 Air Suspension, 150 mm Travel, Compression Adjust with Lockout, Rebound Adjust, 36 mm Stanchions, 51 mm Rake, Boost 110 mm Hub Spacing, 15 mm Thru-Axle with Quick Release

BULLS Branded Eccentric, Aluminum Alloy, Double Wall, 584x35c, 32 Hole, Asymmetric Design, Tubeless Ready | Spokes: Stainless Steel, 14 Gauge Front and 13 Gauge Rear, Black with Nipples

Schwalbe Hans Danpf, 27.5" x 2.8" (70-584), 17 to 38 PSI, 1.2 to 2.6 BAR, ADDIX Speedgrip Rubber Compound, EVO Evolution, APX Reinforced, TLE Snakeskin


FSA Orbit 1.5 ZS (No. 57), Threadless, Internal Cups, Sealed Cartridge, Tapered 1-1/8" to 1-1/2"

Monkey Link Branded, Aluminum Alloy, 55 mm to 80 mm Length Depending on Frame Size, 0° or 7° Rise, 31.8 mm Clamp Diameter, Two 10 mm Spacers, One 5 mm Spacer

Bulls Branded, Aluminum Alloy, Low-Rise, 760 mm Length, 15 mm Rise, 9° Bend, 31.8 mm Bore

BULLS Branded Velo, Flat, Rubber, Locking

Limotech Jovial Dropper (75 mm 100 mm 125 mm or 150 mm Travel)


Selle Royale Vevo

Wellgo ZZE-01M Alloy Platform, Cage Style

Hydraulic Disc

Shimano BR-M8120 Hydraulic Disc with 203 mm Rotors, Quad-Piston Calipers, Shimano BL-M8100 Two-Finger Levers with Adjustable Reach

More Details


2 Years Drive Unit, 4 Years Battery, 5 Years Frame

United States, Canada


16.14, 17.32, 19.29, 21.25

Medium 44 cm: 17.5" Seat Tube, 22" Reach, 29" Stand Over Height, 35" Minimum Saddle Height, 30.25" Width, 76.25" Length, Medium 49 cm: 19.25" Seat Tube, 23.25" Reach, 30.25" Stand Over Height, 37" Minimum Saddle Height, 30.25" Width, 76.5" Length

Matt Black with Gloss Black and Silver Accents

Bottle Cage Bosses, MonkeyLink Lights, MonkeyLink Bottle Adapter

Shimano BR-M8120 Hydraulic Disc with 203 mm Rotors, Quad-Piston Calipers, Shimano BL-M8100 Two-Finger Levers with Adjustable Reach

Video Reviews

Written Reviews

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 with you, this video and writeup are not meant to be an endorsement of BULLS products. I welcome your corrections, additions, and feedback in the comments below and the BULLS electric bike forums.


  • Compared to the 2018/2019 version of this bike, BULLS has updated the drivetrain to a 12-speed withy 10-51 tooth cassette, this give riders an even wider range of gearing options for climbing or reaching high speeds during descents
  • Compared to the 2018/2019 version of this bike, they brakes have been updated and the seatpost has also been upgraded (it now offers a bit of shock absorption as well as being a dropper post


  • I really like the Brose Drive S Mag motor, it’s compact, relatively lightweight, powerful, but not super loud… since it measures pedal torque, pedal speed, and bike speed, it feels natural and even in the highest level of assist, it doesn’t feel jerky or out of control
  • Plus sized tires have become very popular on electric mountain bikes (and even some city bikes) because they provide some additional comfort with the increased air volume, stability because of the increased width, and the drag and weight is compensated for by the motor assist, Schwalbe is a top name in tires and the Hans Danpf performs great in all mountain ride settings… the rims and tires come tubeless ready so you can convert and save weight and run them at lower pressure
  • To support the wider plus sized tires, the hub spacing on this bike has been extended to Boost, so that’s 110mm up front and 148mm in the rear, this gives the spokes a sturdier bracing angle and the thick 15mm front and 12mm rear thru-axles provide increased stiffness and strength, both offer quick release for easier trail maintenance and transport
  • Many full suspension electric bikes forego water bottle cage bosses on the downtube due to rear shock positioning and sometimes battery style… but the BULLS E-STREAM EVO AM 4 27.5+ includes them because it uses an internal battery pack and an upright rear shock
  • BULLS has been including magnetic Monkey Link accessory mounts on many of their electric bikes, which allows for easy-access water bottle, front and rear integrated lights, or a fender accessory… these are great, but they do cost a bit extra and aren’t included with the bike
  • This ebike is completely blacked out and looks great, I love the black anodized stanchions on the shocks, black spokes, rims, crank arms… even the dropper seat post is black
  • For 2020, BULLS upgraded the brakes to use Shimano ICE Tech rotors and heat-sink calipers. They are light, stay very cool, and the sizing remains powerful with an extra large 203mm rotors and quad-piston calipers! I also like the the brake levers have tool-free adjustable reach so you can fine-tune based on brake pad wear or gloved and ungloved hands
  • Excellent weight distribution, the motor and battery are positioned centrally and very low on the frame, the battery is not mounted on top of the downtube but inserts from below and has a nice rubber guard built onto it, this positioning improves balance and ride performance
  • I like how BULLS has designed their wheel speed sensor to be integrated into the rear brake rotor, the reader is tucked away and the whole system is less likely to fail due to mud, environmental impacts, or loose spokes… it’s great
  • Enormous battery capacity here, this is one way that the Brose drive system has pulled ahead of Bosch for the current generation… though Bosch has higher capacity 625 watt hour packs on the way too. You get roughly 750 watts here, and with the efficient mid-drive Brose motor, the bike should get excellent range, less need for a second pack or carrying the charger along due to range anxiety
  • I really like how BULLS is using a fast charger from BMZ, it makes filling the large 750 watt pack faster and more convenient, I also like how it uses a magnetic plug interface so the connector is less fragile and also won’t pull the bike over if tripped on
  • You get four frame sizes with this eMTB, so you can really dial in the fit… to me this is important on active riding bikes where you’ll be pedaling more aggressively or changing body positions to shift weight on technical terrain, it adds to the price but is very nice to have options and dealers to test them out at
  • Both the frame and hardware accessories like the seat post and stem length vary between bike sizes, for me this is very important because I want full leg extension and the smaller frame size just wasn’t giving that to me during the test rides (we manually raised the seat post base by feeding the dropper cables through with a bit more slack)
  • Nice oversized slap guard on the right chain stay and great derailleur with the one-way clutch system to reduce chain bounce, I like the wide spread of the gears and also that the chainring uses narrow-wide tooth layout to reduce drops on bumpy terrain, the ethirteen chain guide is another little upgrade that prevents chain drops and might deter clothing from snagging on the chainring teeth if you’re wearing pants
  • This is a little thing, but I appreciate how the trigger shifters here have a two-way high lever and four-shift low… so you can really dump gears when you’re approaching a steep hill
  • Both shock absorbers are air and can be sagged to your body weight, adjusted for compression, and rebound adjusted to work with the environment, they are top of the line and weigh less than spring suspension while still being durable due to thicker stanchions (the fork uses 36mm stanchions)
  • The motor feels very well protected here because it has an alloy skid-plat built onto the bottom vs. just plastic with some of the other ebikes, however, this bike does weigh a bit more (~56lbs) due to this, the rear shock stanchion fender, the plus sized tires, and the high capacity battery pack
  • I like the transflective display and appreciate that the control pad has a dedicated lights button and walk mode if you hold up, the control pad and battery are so sleek, this ebike blends in and is stealthy, especially with the quieter Brose motor with Gates carbon belt system inside
  • The motor and motor controller system feel super tight, it starts up quickly but very responsively… and then it cuts out almost immediately when you stop pedaling, there’s a great sense of control and precision with the Brose Drive S Magnesium motor and that’s critical for a high-end electric mountain bike and technical terrain


  • The battery pack removes from the bottom of the downtube and I’ve heard that this configuration can be a bit precarious and that the battery pack can get damaged easily if dropped. Since the bike doesn’t come with a kickstand, just be extra careful… I wish the battery locking core was on the right side of the frame so you could unlock and remove the pack while laying the bike down on its left side (non-drive side is less fragile than the right side)
  • The battery charging port on the frame is very low and on the non-drive side of the bike… ideally, it would be up high and on the right side so you don’t have to bend over and so that the bike can be laid down on the non-drive side since it doesn’t have a kickstand
  • Priced at $6,299 the E-STREAM EVO AM 4 27.5+ is at the higher end of the ebike market and at the top of the BULLS product line, you get premium drive systems and bicycle hardware here, but it might be outside the price range for a lot of buyers
  • Unfortunately, you have to buy the additional lights and bottle setup, $170 for the lights, and $46 for the bottle, this seems kind of high, especially since the bike is already at $6,299
  • The Brose ebike drive system does not offer shift detection, so be careful if you’re pedaling hard while using a high level of assist and shifting gears rapidly… it’s best to ease back a bit, so the motor doesn’t put too much tension on the chain and bend the sprocket teeth as you change gears
  • As great as the battery charger is, being fast and using a magnetic Rosenberger interface, it does weigh more at 1.9lbs and is physically larger than many competing products, so it’s less fun to bring along
  • I like the compact display/control pad from BLOKS, but there is room for improvement, it could show battery percentage instead of just five bars representing 20% steps, and it could have a range estimator system, it would also be nice if there was a Micro-USB port built-in so you could tap into the high capacity ebike battery, especially since there is a Bluetooth feature so you can use a smartphone app with the bike
  • I wish that there was a little bit more backwards pedaling resistance so the cranks wouldn’t spin a bunch if you accidentally slip off or kick them, I demonstrate this in the video review at 18:05
  • If you do get that rear light, you might want to be careful about dropping the seat post, because it could come down and strike the top of it, something to be mindful of since the light sticks up above the seat clamp and the dropper post allows the saddle to get very low near the clamp
  • The display cannot be easily removed, nor can you swivel it once it’s tightened down, I like that it is small and out of the way, but some may prefer a larger screen
  • I noticed the charging port is positioned next to the crank arm so that could get in the way of the pedals, luckily though, the cord is magnetic, so if it gets pulled, it should remain mostly undamaged

Comments for 2020 BULLS E-STREAM EVO AM 4 27.5+ (4)

Post a Comment for 2020 BULLS E-STREAM EVO AM 4 27.5+

Name and email are optional. Your email address will not be published.