To run the forums, host the website, and travel, I charge a universal service fee for my reviews. This review was sponsored by BULLS. My goal is to be transparent and unbiased, this video and written review are not meant to be an endorsement of BULLS products.
Today we are looking at the BULLS E-Stream EVO AM 3 27.5 Plus. There is a lot in that name, so what is it exactly? Well the AM stands for all mountain, the 3 is the component level, and the 27.5 Plus is going to be the tire size. The bike comes in 3 sizes (44cm, 49cm, and 54cm) and one color, matte black with these neon accents. It’s using the new Brose high power mid-drive system, the S Mag (sport magnesium), which is 15% lighter, is very responsive, quiet, and very fluid. A lot of people will compare this to the AM 4 which is $6,299. The AM 3 is more affordable at $5,799, but while you save $500, you do loose the Ergon grips, Magic Mary tires, and having both front and rear brakes being quad piston, where as the AM 3 has only quad piston in the front and dual in the rear. But other than that, a lot of great stuff is here. The grips may be Velo instead of Ergon, but they are still locking and have a great aggressive and flat feel. The tires are not Magic Mary’s, but instead you still have these great Nobby Nick’s, still 27.5 x 2.8 plus size, and they give you some great float and excellent grip. This full suspension here utilizes a FOX setup with 150mm of travel and 36mm stanchions on both the front and the rear, so really great for descending or light downhill. They also both have compression adjustment and full lockout, air pressure settings, and rebound adjustment. Each suspension is coated in this this anodized surface, and the rear has a stanchion guard so that helps keep them protected from debris and looking good. Assisting the full suspension is this Kind SI 120mm dropper seat post which can be adjusted in real time, great for when you are switching terrain. Going back to the tires and wheels, I see a 15mm through axle in the front with some 14 gauge spokes and 110mm boost hub spacing which is a little wider so it provides a sturdier bracing angle. In the back it has 13 gage spokes with 148mm boost hub spacing, so again, the same benefit. I love how the quick release has a little dial to adjust the positioning of the lever so you can really get it out of the way for your ride. Working our way to the handlebar, you notice it has a slight bend with a bit of a rise and a couple of spacers here so you can dial it in and make it more aggressive if you wanted. The seat is a Royal M1 BULLS branded saddle, which is pretty firm, maybe a little too firm for my personal taste, but still a very quality saddle. It looks like the bike has kickstand provisions that are nice and out of the way of the crank arm, so that’s nice. I also wanted to mention the Monkey Link bottle option. Although $46 is a lot to pay for a bottle, it is very intelligent setup using this magnetic easy-on-easy-off type system. Also they have Monkey Link light provisions for both the front and rear. Again, these are magnetic and tap into the high capacity battery and is just a really clever setup. However, the cost to this is very high too, as the sight setup is an additional $170. I did notice if you get that rear light, you might want to be careful about dropping the seat post, it could come down and strike that. Overall the setup weighs 55.4lbs total and really balances comfort, performance, and reliability.
Driving the bike is a compact mid-motor from Brose with redesigned casing that uses less material. It’s also using a lighter weight material; magnesium verses aluminum alloy. My guess is that the internals are similar to the Drive S ALU but the weight dropped from 7.5lbs to 6.39lbs. You still get a very narrow Q Factor, optimal spindle placement (to reduce chain stay length for snappier turns and a shorter overall frame length), and excellent ground clearance. This motor is compact and has a sturdy plastic skid plate below, in case you do take a rock or log strike with the suspension fully compressed on a drop. Note that the crank arms are 165mm vs. 170mm to reduce pedal strikes. So, the motor unit is small, but it really packs a punch. You get 250 to 560 watts of power output with up to 90 newton meters of torque! That’s extremely high for a mid-drive unit. Power is delivered based on your rear wheel speed, pedal cadence, and pedal pressure. The new Shuttle mode is all about torque, allowing you to raise it in lower cadence situations, sacrificing battery efficiency for more help if you prefer to pedal slow and reduce cardio while climbing. I personally love this feature because my knees are sensitive and I don’t always want to pedal fast. If, however, you do want to spin, the Brose motors all support 120+ pedal RPM. This means it won’t drop out on you while downshifting on approach to a big hill. Moreso than many other competing products, the Brose motor really hangs in there at high pedal speeds. The Drive S Mag is light, more powerful, and amazingly… more efficient than its predecessors, but it’s still quiet and smooth because it contains a Gates Carbon belt drive that transitions from gears to spindle output. This reduces vibration and provides an organic feeling to the pedal experience that I can vouch for. The older Drive S was my favorite between Bosch, Shimano, and Yamaha for this reason, and Brose is expanding its support and presence in North America. There’s no pedal drag if you do choose to pedal unassisted (no reduction gearing) and the motor is decoupled from pedal strokes beyond the maximum supported speed of 32km/h (20mph). It’s an outstanding drive system, but I do feel that the charging port positioning, on the left side of the motor bulge, requires additional bending over and is in the travel path of the left crank arm… which could get snagged or bumped out of position. At least it’s magnetic with a leash, so it won’t break, and the cover seems very durable. Mechanically, the bike has a 36 tooth chain ring up front with a light weight plastic guide. In the rear you have an 11-46 sprocket, so really nice and big with a great range for climbing. The derailleur is a Shimano Deore Shadow Plus clutch, so you can tighten it or put it down for wheel maintenance or neighborhood riding. Stopping the bike are these lovely Magura MT4 and MT5 hydraulic disc brakes. 203mm rotor in the front (so it is extra large and cools better) with quad pistons, and 180mm rotors in the rear with dual pistons.
Powering the bike is a 37v 20ah lithium-ion battery pack. This battery is a big win here as it is really high capacity with that amp hour rating…. Its bring in about 740 watt hours, so really just a great battery for all day riding. There is no battery cover here, but it does have this impressive aluminum alloy incasing that is actually IPX rated, so overall, very durable. The battery is about 8lbs and has this nice handle for transporting. There is also a battery readout infographic so you can check the charge level without putting it on the bike. The battery is secured via lock and key and it is using an Abus system that can be key-to-like with other Abus locks so you only have to carry around 1 key. I love the magnetic interface here for charging, very easy to use and clean setup. The charger itself has a magnetic cable too, and it is about 1.9lbs, so pretty portable. I love that it charges at 4.7amps…. That’s really fast and a great paring with this high capacity battery. To really care for this and other lithium-ion packs, I have heard that storing in a cool dry location vs. extreme heat or cold will extend the life and try to keep it about 50% full when not using for long periods so you won’t stress the cells. Try not to let it run down to zero, because that’s really hard on the cell chemistry.
Operating this BULLS bike 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. Going back to the quiet motor and integrated 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 Monkey Link compatible lights.
All things considered, I really really enjoy the AM 3, its comfortable, has great performance, and that Brose S Mag motor is super super super quiet. There are some tradeoffs to consider though… some of them may be small, but small issues can add up so let’s see if they are livable for you. 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. I was a little surprised there was no USB port for charging to take advantage of that high capacity battery. Probably the biggest gripe would be having to buy the additional lights and bottle setup, $170 for the lights, and $46 for the bottle. This seems kind of high, especially since this would put the bike at over $6,000 total. If you do get that rear light, it is in the way of the dropper seat post, so that was also disappointing. However, the bike is really a stand out performer and these tradeoffs may seem trivial. I love the comfortable full suspension, the high capacity battery, and the quiet, powerful, lightweight motor. Backed with a 4 year warranty on the battery, 2 year on all other electrical components, and a dealer network, the BULLS E-Stream EVO AM 4 is a stand out performer. A big thank you to BULLS for having letting me try out the bikes on some beautiful trails.
As always, I welcome questions and feedback in the comment section below. Whether you own a previous version of the bike, have taken a test ride, or are brand new to the space, my goal is to provide an objective and honest resource. You can also join the BULLS Ebike forums and share your own photos, videos, and review updates to help others! Have fun out there, and ride safe :)
- A full suspension all mountain bike with plus size tires, hydraulic disc brakes, high capacity battery, and a lightweight Brose S Mag mid-drive
- The Brose S Mag (sport magnesium) is 15% lighter, is very responsive, quiet, and very fluid, I enjoyed not only its capabilities at higher RPMs, but also it’s ability to work well in varying situations
- Great Nobby Nick’s tires, 27.5 x 2.8 plus size, and they give you some great float and excellent grip
- The full suspension here utilizes a FOX setup with 150mm of travel and 36mm stanchions on both the front and the rear, so really great for descending or light downhill
- Both suspensions have compression adjustment and full lockout, air pressure settings, and rebound adjustment, each also is coated in this this anodized surface, and the rear has a stanchion guard so that helps keep them protected from debris and looking good
- I love the Kind SI 120mm dropper seat post which can be adjusted in real time, great for when you are switching terrain or riders
- The handlebar has a slight bend with a bit of a rise and a couple of spacers here so you can dial it in and make it more aggressive if you wanted
- I like the Monkey Link bottle option, it is very intelligent setup using this magnetic easy-on-easy-off type system, also they have Monkey Link light provisions for both the front and rear, again, these are magnetic and tap into the high capacity battery and is just a really clever setup
- Hydraulic brakes are a big preference for me, so I was happy to see a 203mm rotor in the front (so it is extra large and cools better) with quad pistons, and 180mm rotors in the rear with dual pistons
- This 37v 20ah battery is a big win here as it is really high capacity with that amp hour rating, it’s bringing in about 740 watt hours, so really just a great battery for all day riding
- The battery is also housed in this aluminum alloy casing, so very durable and protected
- I love the Energy Bus Rosenburg magnetic charging system, the cables and ports are both magnetic so it makes attaching and detaching easy, while reducing damage from violent cord pulls
- The display is compact, out of the way, and very minimalist, definitely helps the stealthy feel of the lightweight Brose motor and integrated battery
- Versus the AM 4, you save $500, but you do loose the Ergon grips, Magic Mary tires, and having both front and rear brakes being quad piston, where as the AM 3 has only quad piston in the front and dual in the rear
- The seat is a Royal M1 BULLS branded saddle, which is pretty firm, maybe a little too firm for my personal taste, but still a very quality saddle
- 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 this would put the bike at over $6,000 total
- If you do get that rear light, you might want to be careful about dropping the seat post, it could come down and strike the top of it, something to be mindful of
- No USB charging here, it seems like a bit of a missed opportunity given that high capacity battery with a massive 20ah rating
- 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
Peter3 years ago
I want to use this for commuting. Is it easy to change the seat post to my Cane Creek long-travel suspension seat post? Thanks.Reply
Court3 years ago
Hi Peter, I’m guessing it’s possible, especially if you’ve got a 27.2mm diameter Cane Creek Thudbuster. The diameter of the seat tube on the E-STREAM EVO AM 3 is 30.9 which means you could use a shim (just search for a shim that works with 27.2mm to 30.9mm). However, if your post is 31.6mm (or anything larger than 30.9mm) then no, it won’t work.Reply