BULLS COPPERHEAD EVO AM 3 Review

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.

Observations:

• Bosch Gen 4 motor no longer uses a reduction gear, the standard sized chainring freewheels without producing any drag and the Performance Line motors don’t clunk when you stop pedaling
• BULLS really stepped up their game with the charging port and battery locking core position, both up high and on the right side of the frame with a leash so the cover won’t go missing
• The Powerpack 625 weighs a pound more than the 500 (~14% heavier) but gives you 25% more battery capacity! It’s a bit of a trade-off for an all mountain electric bike, where being able to lift the bike, handle it on rough terrain, and put it on car racks makes weight savings important… but it means you can use eMTB and Turbo assist more frequently without running out of juice

Pros:

• BULLS moved the charging port and locking core for the battery up high and on the right side of the frame, exactly where they should be! This means you don’t have to bend down to charge or unlock and if you lay the bike down on the non-drive side (as you should to protect the derailleur) you can still access them! Great job here BULLS, especially given your choices on prior-year models
• Customized tire mix, BULLS has chosen the Schwalbe Magic Mary up front with softer rubber and larger knobs to improve steering, and the Schwalbe Hans Dampf in the rear with harder rubber and smaller tighter knobs to increase surface area and traction when pedaling
• High performance Fox air suspension with thicker stanchions to reduce stiction by reducing flex… the burlier fork provides added strength for the Boost hub spacing and larger/heavier plus sized tires
• I was told that Bulls does not use the official split-pivot rear suspension design but it looks very close and provides the same sort of isolation and vertical travel vs. an arched movement which can change your chain tension and produce kickback… whatever it is, I like it
• Beautiful looking bike, everything is blacked out (rims, spokes, suspension stanchions, dropper seat post stanchion) and the fork is color matched too… black is a popular color for ebikes because they tend to have more cables, display panels, and motor casing exposed
• The COPPERHEAD EVO is available in two frame sizes for optimal fit and ride control, this is part of what separates BULLS and other high-end brands from more affordable products in the space today, I covered the smaller 44cm frame in this video review and in the photos but they also sell a 48cm frame (which I would have preferred because I was maxing out the dropper height and not quite getting full leg extension given my 31″ inseam length)
• This model comes with MonkeyLink magnetic bottle interface as well as headlight, tail light, and rear fender mounts! Not everyone will need lights for an all mountain electric bike, but if you do add them, they will run off of the main battery pack… and of course, you can remove the magnetic bottle adapter on the downtube to get access to standard threaded eyelets for an aftermarket water bottle cage or accessory
• Larger tougher slap guard than many competing electric mountain bikes, it only covers the top of the chain stay but is very long and well mounted, I also appreciate the small/lightweight plastic motor protector at the bottom bracket, and plastic chain guide that helps to reduce drops and protect pants
• Adding to the reliability of the plastic chain keeper is a 34 tooth narrow-wide chainring from SRAM that really locks onto the chain, so pedaling and motor power and transferred more efficiently… it’s a tight drivetrain
• Huge 11-52 tooth spread on the 12 speed SRAM drivetrain, this gives you plenty of range to work with for climbing and reaching/maintaining higher downhills speeds
• BULLS updated their battery cover design to a more universal black plastic, which is much lighter than the older aluminum alloy shields that were paint matched… these are lighter, cheaper, and much easier to replace
• I love that BULLS added provisions for mounting a kickstand at the left rear portion of the frame… most people won’t do this for real mountain biking, because it would bounce up and down on the rough terrain, but it’s nice for urban and light trail riders who want a reliable way to store the bike in a crowded garage
• stiff thru-axles and wider Boost hub spacing provide support for the heavier rims and tires, the spoke bracing angle is sturdier as a result, and you might experience less disc brake zing because the hubs won’t flex like a 9.8mm skewer, I also love the name brand DT Swiss rims with reinforcement eyelets which are less likely to crack under pressure
• Extra stiff e-bike specific Storm model disc brake rotors from Magura, the larger 203mm size front and rear rotors cool faster and provide a mechanical advantage for the heavier build of this bike, quad piston calipers support a larger brake pad that grabs more surface area and cools faster than a dual piston setup
• The Limotech Jovial dropper seatpost provides a bit of shock absorption, which can come in handy if you take an unexpected hit with the saddle in a high position… it’s not much, it doesn’t rattle or anything, it just springs down a little with pressure
• The Bosch Performance Line CX motor has gotten a lot smaller and lighter for the fourth generation, weighing 2.5lbs less than Gen 3, it still offers 75 newton meters of peak torque, shift detection, and eMTB mode which provides a full range of power as pedal torque increases, so you don’t have to think about adjusting the power while also adjusting your gears
• The Bosch ebike motor controller measures rear wheel speed, pedal cadence, and pedal torque over 1,000 times per second and is one of the more reliable and reputable ebike drive systems around, they partner with Magura to provide great customer support across North America and offer a solid two-year comprehensive warranty
• BULLS has integrated the magnet for measuring rear wheel speed into the disc brake rotor, so your wheel can stay more balanced, spokes won’t get loose, and the magnet itself won’t get spun out of place or bumped as easily… the reader is also more protected
• It looks like the bike comes with decent plastic platform pedals, locking semi-ergonomic Velo grips, and a more comfortable Selle Royal Vivo saddle
• With the more compact motor and internally mounted Bosch Powertube battery pack, the bike is pretty stealthy, it doesn’t stand out… the cables are mostly internally routed and the ebike system weight is kept low and center for better handling
• I noticed a couple of unique hardware upgrades on the BULLS COPPERHEAD EVO AM 3 including a rectangular spacer and stem system that routes cables internally… the rectangle spacers split down the middle so you can add and remove them without disconnecting anything, and the thicker 1-1/2″ straight head tube vs. tapered 1-1/8″ to 1-1/2″ I see elsewhere
• The Bosch CX motor does use more electricity and produce more noise because of the zip and torque on offer so I like that they went with the high-capacity Bosch Powerpack 625 and that you get the 4 amp charger for faster turnaround time, the charger is relatively lightweight, compact, and can fill the battery on or off the frame without the need for any dongles… the proprietary plug interface is durable and won’t get confused with other charging devices you might own… it’s my favorite charger!
• You get the nicest Bosch battery pack on offer for this generation of products, with 625 watt hours on offer, you can ride further without the need for a charge… or you can use higher levels of assist longer without running out of juice, the pack is durable, standardized across other Bosch powered electric bicycles, and has a two-step release so it won’t tumble out if you want to remove it to lighten the weight of the bike or just store it separately (avoid extreme heat which can damage cells and extreme cold which limits the usable capacity temporarily)
• The battery pack locks into the frame using an ABUS core with PLUS keys that can be matched to ABUS locks, it’s a great setup and one of the highest-end locksets around, more info on the official ABUS website here
• BULLS has a vast network of dealers in the US and Canada, they entered into the North America market from Germany (and Europe) around 2016 and have a strong management and field team, I feel confident that their brand will persist and grown here while some other companies have been less stable, having access to dealers for fitting, tuneups, and post-purchase support is part of what makes this a more expensive bike but also gives you a great end-user experience
• The Bosch Purion display panel is a bit smaller and less feature rich than the Intuvia or Kiox, but it still provides dynamic range readouts, which can help reduce range anxiety on longer bike rides, I like how small and simple it is to use… and some shops will special order other Bosch displays and help you upgrade from this if you want more stats or a larger or color display
• All of the Gen 4 Bosch Performance Line motors now offer 120+ RPM pedal support, meaning that the motor can keep up with greater than 120 pedal strokes per minute, so you won’t be left without power when downshifting and spinning approaching a steep hill
• I like that the BULLS electric bikes have walk mode enabled, it can really be useful for climbing a steep section of trail if you get off your bike (especially if you’re wearing clip-in shoes) or if you get a flat tire, just press the walk mode button on the lower edge of the Purion display and then hold plus to make it go

Cons:

• It’s great that the drivetrain has such a wide spread of gears, because the bike is fairly heavy at ~56 pounds (~25.4kg) which comes back to the medium sized 2.8″ wide plus sized tires, longer travel 150mm suspension, straight 1-1/2″ head tube, and high capacity Bosch Powertube 625 vs. 500 on other models
• Only the front wheel offers quick release, the rear wheel uses a 6mm hex bolt, so you’ll need a tool to perform trail maintenance, there’s not toolkit built onto the bike or secret tools stored under the stem cap or elsewhere like we’ve seen on some of the Specialized models
• The SRAM trigger shifter offers a one-direction high lever vs. two-direction on many Shimano parts that I test… but at least you get a four-shift low lever for dumping gears when approaching a steep hill. I like that SRAM didn’t nerf this shifter like so many others that I’ve seen on ebikes where you only get one gear change at a time (for concern about damaging the drivetrain) this may be the result of pairing with the Bosch drive system that includes automatic shift detection
• Despite moving away from the reduction gear (with smaller chainring) the high-powered Bosch ebike motors still produce a fairly audible whine at high RPM and high power settings, it’s not a deal killer, but seems a bit louder than Brose at times
• Perhaps it was just the demo bike, or a feature that is being fine tuned still, but the battery took a bit of extra time and effort to mount back into the frame… I feel like we had to twist the key to allow the battery to click into place and this took two of us to accomplish, while stabilizing the bike, it would be nice if you could just push and have the battery click into place seamlessly and not have to mess with the key at all
• Given the high capacity battery pack, it would be nice to have a USB port to plug a phone in for use with GPS, music, or other portable electronics… the Bosch Purion display panel has a Micro USB port, but this is only usable for data transfer and updates, not charging, consider swapping the display for a Bosch Intuvia or Kiox which do have active Micro USB ports, dealers can help with this for a hardware and service fee $150+
• This is a minor thing, but the chainring doesn’t cycle backwards when you backpedal, this changes how drivetrain service is done… you basically need a bike maintenance stand or a friend to lift the bike and pedal to clean and lubricate the chain. One positive note here, is that Bosch has setup the bottom bracket with some resistance so the cranks won’t spin as freely backwards, which could lead to more shin scrapes and shin bumps otherwise
• Be careful when lifting and transporting the Powertube battery because it does not have an integrated handle like the Powerpack mid-frame and rear-rack models, I do appreciate how it clicks down one step before completely coming off the bike, you are less likely to drop it when removing

Useful Resources:

• Official BULLS North America website
• Bosch Purion display panel settings
• Bosch Gen 4 ebike motors (including the Performance Line CX)
• Fazua vs. Bosch ebike motor comparison