The Shimano EP8 motor may be the most important ebike motor released to date. The outgoing E-8000 motor is what is found in the largest selection of e-mtbs today and has been proven to be dead reliable! Launched in May 2016, the Shimano E-8000 redefined the state of e-mtbs since it was a compact and reliable system that was available to all manufacturers with the support of the Shimano network.
But they have learned many things over the past four years and have improved the EP8 successor in the following ways.
- Torque has been increased from 70nm to 85nm
- Weight has been decreased from 2.9kg to 2.6kg, a weight savings of 300g using a magnesium case
- Battery capacity has been increased from 500wh to 630wh
- Size has been decreased by 10%, allowing better ground clearance
- The EP8 motor is bolt compatible with the E-8000 allowing an easy upgrade path for manufacturers.
- Drag has been decreased by 36%
- Noise has been reduced. It is even quieter than th E-7000 with less power
- Software has been dramatically improved allowing more options and condigurabity
- Startup and shutdown of assist is more seamless now. And turbo mode is more usable
- Walk mode is a lot more usable now with good power, in any gear
- One can turn on the motor now while pedaling, just not pedal too hard at start-up
EP8 Drive Unit
The EP8 drive unit (DU-EP800) benefits the overall bicycle design and ride feel through a more natural and refined power delivery thanks to the lighter, quieter, more compact, and powerful motor with increased range.
EP8 delivers up to 85 Nm of torque, a 21-percent increase over the STEPS E8000 motor platform. The new magnesium drive unit casing design delivers a 300g weight loss in a 10-percent smaller form factor. The EP8 drive unit shape more smoothly integrates with new e-bike frames for improved ground clearance and a more compact overall package.
Heat dissipating materials, increased surface area in the case, and a refined heat management algorithm improve heat resistance, allowing more torque to be applied even as the conditions become more challenging. Thanks to a new seal structure and gear design, drag is reduced by 36- percent, getting much closer to the normal pedaling feeling of a traditional bike. Riders will feel a smoother cut off as they reach the maximum assist speed and then benefit from lighter pedaling without assistance.
Display and controls
The new EP8 computer display (SC-EM800) shares many external similarities with the SC-E8000 display, but with new features including a more capable chipset, expanded compatibility with third party computers, and the ability to select two different custom ride profiles.
The SC-EM800 computer communicates wirelessly with Shimano's E-TUBE PROJECT app via Bluetooth, allowing riders to instantly customize power characteristics on demand. The SC-EM800 can also communicate with third party cycle computers through the ANT wireless protocol to display more detailed battery capacity and power output info in addition to ride mode, speed, gear position, range, and odometer.
New batteries recently released by Shimano are available for EP8, including two 630Wh battery options, the external BT-E8016 and internal BT-E8036 battery. Like their predecessors, all Shimano STEPS batteries are extremely long-lasting, taking up to 1000 full charge cycles while maintaining 60-percent of their original capacity, double the charge cycle capacity of other batteries, often outlasting the average e-mountain bike ownership.
New Assist algorithm
Shimano's experienced global mountain bike product development team made a ride-changing breakthrough with the new assist algorithm. Instead of a single assist ratio for each riding mode, the new algorithm constantly calculates the ideal assist ratio for the situation. This simple concept improves the ride quality in all situations, eliminating the lurch forward and wasted energy as the bike accelerates while also continuing to provide additional assistance when the trail gets tougher and the rider works harder. The rider feels more connected to their bike as they naturally modulate their own power to navigate slippery roots and urge the bike over large boulders while the EP8 drive unit matches their intuitive power application instantly and seamlessly leading to better traction and effortless steering.
The new assist algorithm is so effective that riders will find that they no longer need to rely on BOOST mode to clear the most difficult sections of the trails they ride. With all 85 Nm of torque being available in TRAIL mode and the algorithm continually increasing the assist ratio, it's possible to ride all but the most demanding terrain without changing modes. At the same time, riders will notice an increase in range simply because the new assist algorithm doesn't waste energy when it isn't needed. If riders prefer the additional support provided by boost mode or they plan to tackle next to impossible climbs, they will appreciate the greater bike control even with maximum power delivery in boost thanks to the new algorithm. ECO mode has also gotten much more economical thanks to the new algorithm as well. It can now double the range compared to trail mode, becoming a very useful tool for maximizing ride time.
Enhanced E-Tube technology furthers customization
Shimano E-Tube technology has undergone a complete overhaul to improve the user experience. Riders can customize multiple settings through the E-TUBE PROJECT app, giving greater control over how they want their bike to ride. With EP8, the BOOST, TRAIL, and ECO modes can be customized with ten different assist curves which control how quickly the power ramps up to match their effort. Additionally, the maximum torque limit can be set anywhere between 20-85Nm allowing riders to increase their riding range in TRAIL or BOOST modes or increase the off-road capabilities of ECO mode. There are five levels of startup assistance available that can further tame the acceleration from a stop for relaxed city riding or apply more power from the get-go when starting on steep mountain bike trails. Riders can save all of their settings as a profile in the E-TUBE PROJECT app and choose two of their favorite profiles to load onto the bike for easy access on the fly through the handlebar-mounted display. This can allow an easy transition between two different riders with different preferences, or it can be used to build a commuting mode and a mountain biking mode.
The updated E-TUBE RIDE app can be used by e-bike riders to monitor all their key riding information in their smart phone as a real-time display. Screen display options show detailed riding metrics in ECO, TRAIL and BOOST modes plus new functions including ride history, live maps, and user-friendly graphical updates. Like the SC-EM800 display, the E- TUBE PROJECT app can also provide maintenance reminders.
Both the E-TUBE PROJECT app and the E-TUBE RIDE app are now available to download from iPhone or Android app stores and are fully compatible with Shimano EP8.
EP8 Technical Features
• Drive unit weight: 2.6 kg compared to 2.9 kg for DU-E8000
• Case material: Magnesium
• 10-percent less volume compared to DU-E8000
• Maximum torque output: 85 Nm
• Maximum power output: 500 W
• 36-percent reduction in drag
• Greatly reduced driving noise, quieter than DU-E7000
• Improved heat management system provides more torque
• 177 mm Q-factor is centered in the frame for a normal MTB ride feel
• Three different crank arm options
• Compatible with all Shimano drivetrains whether Di2 or mechanical
• Chainrings and spider supports many chainline options
• A new assist switch (SW-EM800) better feel
• A new chain guide (CD-EM800) in a drive unit mounted version
This may be the most significant ebike motor ever introduced and its timing couldn't be better. The growth of the category is staggering and the amount of R&D being poured into bikes and integration is growing by leaps and bounds. Shimano is a key force in the category not only because of its integration with the drivetrain components but also because of its reputation and dealer network. Even with an aging E-8000 motor, we've seen more new bikes introduced with the E-8000 motor than any other. The EP8 is head and shoulders above the E-8000 and will open up a whole new array of options for the e-mtb.