2019 BULLS WILD FLOW EVO RS 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:

• UPDATE: One of our shop partners has notified us that Monkey Link “Connect” is not enabled and users cannot attach lights wired to the battery as recorded in this review. Also, the bike may not come with a handlebar remote. I am putting these notes here, because I want the rest of this review to reflect what was seen on site with BULLS, even though the bike shown might not match what dealers are getting now (which is sometimes the case for pre-season reviews as well as prior year content).
• The bike uses 29″ wheels even though it has Boost hub spacing, I’m used to seeing 27.5″ plus sized tires on a setup like this. Perhaps the narrow 2.35″ wide tires reduce friction and weight compared to 2.6″, 2.8″ or 3.0″ and you get a slightly lower attack angle here as well
• For this review, we were looking at the medium sized frame, 44cm, and it felt a little small to me as a 5’9″ guy with 30″ inseam… I wished that the dropper post could have had a longer base or extended higher because I wasn’t getting full leg extension
• This is one of the few full suspension electric bikes that I’ve seen with a carbon fiber frame, this offers some vibration dampening and reduced weight but isn’t as durable as aluminum alloy, the rear triangle is aluminum alloy

Pros:

• The Fazua Evation drive system is incredibly lightweight, it consists of three parts including the bottom bracket gearbox (2.8lbs), removable motor (4.2lbs), and removable battery (3.1lbs), that helps to make the WILD FLOW EVO RS one of the lightest full suspension cross country electric bikes I’ve ever reviewed at just ~42lbs
• Unlike almost every other ebike drive system I’ve tested to date, you can easily remove the Fazua motor and battery (which click together to form the “drivepack”) and replace them with an optional $80 downtube cover to form a non-electric bike that only weighs a couple pounds more than if it were truly non-electric acoustic
• The Fazua gearbox bottom bracket is physically smaller and narrower than most competing mid-drive systems I’ve tested, it features a minimum spindle width of 133mm and smaller q-factor… this isn’t as relevant for the WILD FLOW EVO RS however, given the wide Boost hub spacing
• Sturdy 15mm and 12mm thru-axles on the front and rear wheels provide strength for off-road use and the Boost hub spacing provides a stronger spoke bracing angle, the rear spokes are slightly thicker at 13 gauge vs. the front 14 gauge, I find that thru-axles reduce flex and disc brake rub
• Attention to detail with a clear plastic sticker slap guard that protects the right chain stay, I also appreciate the Monkey Link magnetic light attachments at the stem and seat clamp as well as downtube bottle adapter (which can be removed to reveal standard bottle cage bosses below)
• Available in three frame sizes for optimal fit, given the reduced motor power offered by Fazua it’s more important to be fitted properly on these ebikes because they require more rider work… so starting with the correct size is important and you should be able to test ride this and other BULLS models at their massive dealer network
• The Fazua motor controller measures rear wheel speed, pedal cadence, and pedal torque to provide smooth natural power output… I never felt a strong lurch of on and off like many cadence sensing only ebikes
• Nice Magura MT5 hydraulic disc brakes, 180mm rotors front and rear, with upgraded quad-piston calipers that improve grab by providing a longer and more even braking surface
• The Fazua battery charger is really compact and lightweight, I like that the wall-side cord can be unplugged from the charging brick and that they went with the universal Rosenberger magnetic interface vs. making their own proprietary port, the magnetic plug will simply pop out of the charge port vs. pulling hard and possibly moving the battery or damaging the interface if you trip over the cable
• With such a small and lightweight battery (3.1lbs) it would be easy to buy additional packs to load into bike bags or a backpack to extend your range, almost every single competing ebike battery I’ve seen is physically longer and much heavier
• Impressive two year battery warranty and 30 month drive system warranty from Fazua (distributed by Quality Bicycle Products QBP in North America), plus a five year bike frame warranty from BULLS, I like that there are many shops in North America that carry BULLS products, so you can take test rides, get fitted, purchase accessories, and get help with tuneups
• In Europe, the Fazua motor is limited to 25km/h (roughly 15.5mph) but the North America Evation has been upgraded to reach 32km/h (roughly 20mph) based on different legal framework for Class 1 ebikes, the power output remains 250 watts to 400 watts peak
• Just in case you’re wondering, I was told that the RS in the bike name stands for “racing spec” which makes sense given the high-end Fox air suspension, Shimano Deore XT drivetrain (with extra wide 11-46 tooth setup on the cassette and narrow-wide chainring for reduced drops), and Magura hydraulic disc brakes
• All of the components are black and the paint design looks great to me, notice the black hubs, spokes, rims, suspension stanchions, dropper post stanchion etc. which could have been silver, gold, or other colors if they weren’t scrutinizing every detail
• I like how BULLS has designed the rear wheel speed sensor to be integrated into the rear disc brake rotor for many of their electric bikes, it’s protected better than spoke-mounted magnets and keeps the left chain stay from collecting as much mud and debris

Cons:

• The battery cannot be charged while mounted to the frame! You have to unlock and physically remove the Drivepack each time you want to charge this electric bike, which is inconvenient and hazardous without a kickstand
• If you’re using the default included handlebar Fazua display to operate this ebike, you’ll need to prime the battery by pressing a button at the top end of the pack before the system can fully turn on… and this requires unlocking and half-opening the battery/motor drivepack, this is inconvenient every time you want to ride, especially without a kickstand to stabilize the bike… the one saving grace is that once the battery has been powered on, it will stay alert for about eight hours before going into sleep mode again, during this window of time, the display unit can be activated independently
• In my experience, the Fazua Evation drive system feels weak compared to other mainstream ebikes, it doesn’t provide the same zippy feel when starting or maintain higher speeds as easily, it’s a Class 1 system that is limited to 20mph with a maximum pedal cadence of 80 RPM verses 100 to 120+ RPM offered by Bosch, Yamaha, Brose, Shimano, and Bafang
• Priced at $5,999 the BULLS WILD FLOW EVO RS is definitely at the more expensive end of electric bikes, and in my opinion it’s a compromise between being an awesome electric bike or an awesome acoustic bike… it doesn’t do either perfectly because of the weaker motor and smaller battery and then a slightly heavier/bulkier acoustic bike setup
• With a battery capacity of 252 watt hours (36 volts, 7 amp hours), this electric bike offers less than half the capacity of most other current-generation products which means less support and less range… the motor doesn’t uses as much power and the bike weighs much less than competitors, but there’s still just less support on offer
• The control pad is very basic, there are three levels of assist and a 10-bar battery charge level indicator, you can’t tell how fast you’re going, how far you’ve ridden, or get other detailed feedback without using the optional smartphone app… there is no USB charging port to fill and maintain a phone while using the app and so far, the app has pretty limited features (at least in North America) with battery percentage, motor power level in watts, and current speed in mph or km/h
• This is a little gripe that I have about many mid-drive ebike systems: when you pedal backwards, the chainring does not cycle… the crank arms just spin, which could make servicing the drivetrain more difficult if you don’t have access to a bike stand
• As with most high-end full suspension mountain bikes (electric or otherwise) there is no kickstand included with this ebike, but I would have liked the option to add a kickstand aftermarket using pre-drilled eyelets which appear on some other BULLS models
• The multi-step motor/battery removal process can feel a bit precarious, especially because the battery comes out of the downtube and there being no kickstand… consider getting help or maybe laying the bike down on its left side so you don’t drop the battery or the bike
• The stock handlbar mounted Remote display uses lots of LED lights, and it cannot be dimmed or turned off without de-activating the bike, I feel like the lights could be bright at night and a bit annoying to some riders… black electrical tape could help with this :) I also miss being able to see my current speed, pedal rpm, odometer, trip meter, and other advanced readouts like range that many LCD displays now offer
• The battery locking cylinder is on the non-driveside of the bike… which is the side that generally gets laid down onto the ground, not only could dirt and debris get in, but you won’t be able to reach it as easily if you’re laying the bike down to remove the battery pack since there’s no kickstand
• I don’t think the Fazua drive system offers walk mode, I wasn’t able to figure it out… so please chime in if you’ve got an answer, this could be a bummer if you get a flat tire or have to push the bike up an excessively steep or technical section that isn’t rideable
• It seems like the gearbox bottom bracket makes a loud clicking noise when coasting, it reminds me of high-end cassettes with pawls that click at faster and louder rates if they are more expensive, for me it can be a bit distracting (see in the video at 20:14 and 22:23)