Wil & Mick review Shimano EP8
First revealed to the world in September of last year, Shimano EP8 finally arrived on the e-MTB scene as the successor to the very popular Shimano E8000 motor. As well as being smaller, lighter and more efficient, the new EP8 drive unit also packs more punch with up to 85Nm of torque, bringing it up to speed with the latest power plants from Bosch, Yamaha and Brose/Specialized. Along with a new larger 630Wh battery option, plus updated hardware and software, Shimano certainly hasn’t held back with its much-anticipated return fire on the highly competitive and fast-moving electric mountain bike market.
We’ve been living with the Shimano EP8 motor for six months now across three different bikes; the Merida eOne-Sixty, the Polygon Mt Bromo, and the Canyon Spectral:ON. That’s given us plenty of saddle time to compare and contrast the new motor not only with E8000, but also with the latest Bosch Gen 4 motor and the Brose-manufactured 2.2 motor in the new Specialized Levo. It’s also given us plenty of opportunity to identify all the little quirks, while getting a better impression of long-term durability and performance.
So, how does Shimano EP8 stack up then?
Shimano EP8 overview
While the increased power certainly grabs most of the headlines, we reckon it’s the compact form of the Shimano EP8 drive unit that offers the greatest advantage over its competitors. The svelte motor casing provides more clearance for the rear wheel and suspension components, allowing brands to build their bikes with shorter chainstays. The three EP8 bikes we’ve tested all have sub-440mm rear centre lengths, which is quite a bit shorter than the 471.5mm rear centre on the Giant Trance X E+ with its much bulkier Yamaha motor, for example.
In terms of improvements, EP8 is marginally lighter (300g) and smaller in volume (10%) over the old E8000 motor. Side-by-side, the EP8 motor is slimmer around the belly and so offers a skerrick more ground clearance. This also allows brands to more neatly integrate the motor into their frame designs, Canyon having done a particularly swell job with the Spectral:ON. It’s the Orbea Rise that achieves the most discreet integration however, with a frame that was purpose-built around the smaller EP8 motor, rather than having been retrofitted from a previous E8000 drive unit. Along with the EP8’s magnesium casting, heat sinks and polished logos, it affords a classy look – not an easy feat for an e-MTB.
Neat display & tactile control
The Shimano EP8 user interface is similarly elegant in its design. The low profile EM800 display takes up minimal space next to the stem, featuring a crystal-clear screen with colour-coded graphics to easily identify which assist setting you’re in. The newly shaped buttons on the EM800-L switch unit provide a nice tactile perch for your thumb to quickly flick between those settings. And with brands such as Merida and Canyon making use of internal wiring through the handlebars, the whole arrangement is quite tidy. Overall it’s a vastly neater execution compared to the likes of Bosch and Yamaha with their Kinder Surprise-style switch units.
The EM800 display features built-in Bluetooth and ANT+ wireless connectivity for pairing both your phone and a compatible GPS head unit, allowing you to display information such as battery life and remaining range. However, we couldn’t get the display to pair with our Wahoo ELMNT Roam head unit. Upon a little digging on the internet, it appears that this functionality is only on offer for Garmin users. Hopefully this option will open up to non-Garmin users in the future.
This means it’s impossible to tell whether you have 21% or 49% battery remaining. We’d much rather see battery life displayed as a percentage, and the option to customise the screen.
That said, we’d prefer if there were more metrics displayed on the main screen to begin with, so you could ditch the GPS altogether. As it stands, you have to use the small button at the base of the display to manually scroll through additional pages just to see your cadence, estimated range and the time. Furthermore, having the battery life displayed as five bars is positively rudimentary. This means it’s impossible to tell whether you have 21% or 39% battery remaining. We’d much rather see battery life displayed as a percentage, and the option to customise the screen. In comparison, the MasterMind TCU display on the new Specialized Levo offers a significantly more customisable and overall user-friendly experience.
Along with the new EP8 motor, Shimano has also released a larger 630Wh battery, which seems to be the most popular option at the moment – you’ll find it inside both the Canyon Spectral:ON and Merida eOne-Sixty. This BT-8036 battery only needs a 4mm hex key to be released from the frame for charging separately, which is unlike Bosch that requires a special key (potentially something else to lose/forget).
Additionally, Shimano produces a smaller and lighter 504Wh option, which is also cheaper and helps to bring the complete bike price down – see the sub-$8K Polygon Mt Bromo N8 for example. Then there’s the BT-8035-L battery, which is a 504Wh battery that shares the same physical dimensions as the 630Wh version. This allows bike companies to engineer a single frame, while offering cheaper models with a 504Wh battery, and high-end models with a 630Wh battery.
On top of that, Shimano also appears to be cool with brands building their bikes with non-Shimano batteries. The Pivot Shuttle, for example, employs a huge 726Wh battery made by a third party company called Darfon. The YT Decoy also utilises its own 520Wh battery and the the Orbea Rise is built around a smaller 360Wh battery. Shimano’s battery flexibility certainly presents a significant advantage over the likes of Bosch, which is much more limited with its battery options.
Shimano EP8 on the trail
With 21% greater torque than E8000, the EP8 motor delivers substantially more punch on the trail, and it feels more usable too. Total power isn’t quite as brutish as Bosch and Brose, but the real beauty about EP8 is that it retains the smooth and intuitive performance that we loved about the old motor.
You still have the three basic assist modes: Eco, Trail and Boost. The biggest change has been with Trail mode, which now gives you access to the full 85Nm of torque if you’re pedalling hard enough. This gives a very wide and flexible power band that does well to match what your legs are doing, making this the go-to, set-and-forget mode for proper off-roading.
Pickup is faster too, with less hesitation between pedalling and torque being delivered to the rear tyre. While the motor is both more sensitive and more powerful though, Shimano has done brilliantly to offer usable control of that power. It’s easy to modulate via how much pressure you’re putting through the cranks and the power delivery is progressive, giving it a very natural feel as a result. This is particularly noticeable on traction-poor climbs, even when starting from a standstill.
Aim for a cadence of 70-90 RPM
Improving performance on undulating terrain, Shimano has also increased the EP8’s available torque at lower cadences. However, where the Bosch Gen 4 feels like a diesel engine at low RPMs, the sporty EP8 drive unit still prefers spinning at a higher cadence. Personally, we’re ok with downshifting and spinning our way up a steep incline – it’s better for the health of your knees, and it’s likely better for the health of the motor too. Aim for a cadence between 70-90 RPM for maximum efficiency and response from the motor.
While the EP8’s performance on the climbs is generally excellent, we have occasionally wished for a little more overrun for clearing technical features. This is because the assistance drops off quite quickly when you stop pedalling, particularly compared to the Bosch motor, which continues to push on for just a fraction longer. It isn’t a huge difference, but sometimes it’s just enough for your rear wheel to make it up and over a stubborn tree root or rock ledge. A little more overrun from the EP8 motor, and even the option to tune that attribute via the E-Tube app, would be stupendous!
It’s smoother and quieter….
The EP8’s smooth power delivery is mirrored by its exceptionally low drag – something that is totally noticeable (or rather not noticeable) around the 25km/h cutoff point. Certainly of all the full-power motors we’ve tested, Shimano EP8 affords the most seamless feel as the power fades in and out around the assistance cutoff.
We’ve noticed this while pedalling along forest double tracks and on the road to and from the trailhead, but it’s also apparent when sprinting along faster sections of singletrack. When you’re at those 30-40km/h descending speeds, EP8 doesn’t punish you for stamping on the pedals to build some extra speed in the lead-up to a jump or dropoff. According to Shimano, the EP8 motor offers a 36% reduction in drag over the old E8000 motor, and we’re inclined to believe that claim. There is zero stickiness at the pedals that we could detect.
It’s also a very quiet motor when pedalling. There’s still a whirring noise from the metallic gears inside, and the pitch increases slightly at higher cadences. But overall EP8 offers more of a quieter and gentler hum than the whine of the E8000 motor, and it’s also quieter than the Bosch motor too. Only the Levo’s belt-driven Brose drive unit beats EP8 in terms of motor noise.
… except for that damn clacking noise
Where the EP8 motor isn’t quieter than its predecessor however, is when you’re not pedalling. This is due to the internal clutch mechanism, which allows the motor to disconnect from the cranks when not in use, thereby decreasing drag and resistance. Unfortunately this clutch also produces a metallic ‘clack‘ whenever it rotates back and fourth.
You can hear it in the workshop just by lifting the rear wheel and dropping it on the ground, where it sounds a bit like a loose pebble bouncing around inside a wooden box. When you’re descending down the trail, the volume and resonance are amplified. It’s mostly apparent when freewheeling down really rough trails, but we’ve been able to detect it when the motor is engaging and disengaging around the 25km/h cutoff on the road, and while cruising over washboard bumps on mundane fireroads. Basically any minor impact that causes the chain to bounce and tug at the chainring will result in noise.
But you do get used to it
Now we’ll point out here that the Bosch Gen 4 motor exhibits a similar metallic clacking noise, since its internal gear system also employs a clutch. On the trail the tone of the ‘clack‘ is a little deeper than the EP8 drive unit, but the cause is the same.
Still, given the lengths that bike and drivetrain manufacturers have gone to stealthify mountain bikes over the past few years, we found the noisy EP8 motor to be infuriating during the first few rides – just as we did with the Bosch Gen 4. The thing is though, you do actually get used to that noise. In fact, we found ourselves tuning it out completely a couple of rides later. As in, we totally forgot about it altogether. Most brains will be capable of doing this, as the noise in question isn’t actually signalling a fault with the motor. While some frames will resonate more than others, the noise is otherwise normal, and it doesn’t take long before your brain subconsciously ignores it. Having spoken with other long-term EP8 and Bosch Gen 4 users, it would appear that for many riders it’s a non-issue.
Now, would we like to see Shimano eliminate the noise altogether? Absolutely. But would the noise stop us from recommending an EP8-equipped bike? No, not at all.
Tuning the Shimano EP8 motor
One of the more intriguing aspects of EP8 is the ability to fine-tune the motor’s performance via Shimano’s E-Tube Project app. While there were limited options to tweak the levels of the old E8000 and E7000 motors, EP8 takes it to the next level, allowing riders to alter the motor’s torque, acceleration and general on-trail character, resulting in a more personalised experience for dialling your e-MTB in for your riding style and terrain.
After downloading the free E-Tube Project app, you’ll need to turn the bike on and pair it with your smartphone. Once paired, find the ‘Customise’ menu and select ‘Assist’. Here you’ll find three sliding scales for each of the three assist modes (that’s Eco, Trail and Boost).
1. Assistance Character – This adjusts the motor’s support level, which is how easily the motor delivers its power based on your input. In the lower settings, you’ll have to pedal really hard to get maximum support the motor. In the higher settings, the motor will deliver maximum power without you having to pedal very hard at all. There are 10 levels of adjustment, from Eco to Powerful. This adjustment has the biggest impact on the motor’s performance and your total range.
2. Maximum Torque – This allows you to limit the maximum torque, with 10 levels of adjustment from 20 Nm to 85 Nm. Limiting the maximum torque is something you’ll notice more at low cadences in high-load applications rather than general trail riding. You can improve efficiency by limiting the maximum torque, though it is still possible to get maximum power out of the motor by pedalling at a higher cadence, so you won’t necessarily get more range by limiting torque.
3. Assistance Start – Here you can tweak how quickly the motor responds within the first pedal stroke. There are 5 levels of adjustment from Mild to Quick, with the highest setting requiring only a small rotation with light pedal force to engage the motor. The lowest setting sees the motor responding slower to your pedalling inputs. We’ve found the first two settings to be too weak for e-MTB use, though conversely the highest setting can feel a little too peaky for some riders. If that’s the case for you, start at Level 5 and work your way down a notch at a time.
Set it up for your riding style
Overall the tuning adjustments are quite noticeable, though we’d always recommend only adjusting one parameter at a time to isolate its effect on the trail. As mentioned above, the Assistance Character bears the biggest influence on the motor’s on-trail feel, and dialling this down can make quite a big difference to the amount of range you can get from the battery. Just remember to manually unpair your phone from the bike before you start riding again, as the motor won’t engage while the system is paired to the app.
What settings you end up will depend on your personal riding style, and your expectations of range and power output. It also depends on the bike too. With the Spectral:ON for example, which has very short chainstays and a relatively slack seat tube angle that puts your weight further over the rear axle on steep climbs, it helped to dial down the Assistance Character (to 6/10), the Maximum Torque (to 78Nm) and the Assistance Start (to 4/5) to soften the bike’s power and acceleration. This reduced the tendency for the front wheel to lift on really steep tech climbs.
Also worth noting is that you can create two riding profiles, which you can alternate between via the menu and push-button on the display. We like to setup Profile 1 with softer settings for maximum range when riding solo, and Profile 2 with the punchier factory settings for faster e-MTB group rides.
Maximising the EP8 motor’s range
Though the new EP8 motor is claimed to be more efficient than its predecessor, there is of course more power too. And more power requires more juice. This means that if you ride in the default Trail and Boost settings, you’ll actually end up with a similar total range as the old E8000 motor, albeit with the benefit of more power and assistance throughout the ride. You don’t necessarily go further, but you will be riding and climbing faster.
There are a lot of factors that influence range including rider weight, tyre choice, trail conditions, and elevation. But to give you some numbers, we’ve consistently achieved around 1,500m of climbing during our 30-50km test rides.
For riders scoping out bigger rides than that, you’ll want to consider dialling down the Assistance Character to improve efficiency. Again, shift it down one notch at a time to get a feel for the change. If speed and maximum power output is less of a concern though, switching into the factory Eco mode is a sure-fire way to get more ride time – expect range to double from those figures above.
The range estimation is unreliable
One note on range – Shimano’s range estimation is not reliable. In addition to the challenge of having remaining battery life displayed as five bars, the range estimation tends to drop quite quickly during the final two bars. On one ride with the Canyon Spectral:ON, the range estimation initially showed 25km. A kilometre later that estimation dropped to 14km, then not long after to 9km, then to 5km, before the motor automatically switched into emergency limp home mode. It’s almost as if the battery drains faster in that final 20%. That makes it tricky to work out how much assistance you’ll be finishing your ride with.
Our advice is not to rely on the range estimation in the first place. Instead, we recommend setting aside some time for a battery-drainer test ride, somewhere that is accessible and easy to ride out with a flat battery, in order to work out your maximum range you can get during typical riding conditions. Start with a full battery, select the Trail mode, and see how far you can go before you run out of juice. If possible, repeat this ride on the Eco and Boost modes too. Take note of how much elevation you achieve during those rides (elevation is more important than distance when determining range), and keep that number in mind when you’re planning future all-day epics. This will be a far more accurate method for determining your estimated range.
Shimano EP8 vs the competition
While we’ve certainly been impressed by the power, ride feel and tuneability of the Shimano EP8 system, how does it stack up against the likes of Bosch and Brose/Specialized?
Bosch Performance CX Gen 4
We’ve ridden the latest Bosch Performance CX Gen 4 motor on a variety of e-MTBs, including the Cube Stereo Hybrid 160 and the Trek Rail. The Bosch motor produces the same 85Nm peak torque output as Shimano EP8, and it offers a similarly drag-free ride quality beyond the 25km/h cutoff due to the motor decoupling from the cranks. Of course this means it also ‘clacks’ when coasting over rough terrain, though again, we’ve gotten used to it within a couple of rides.
As mentioned earlier, the Bosch motor does feel punchier than Shimano EP8, with noticeably stronger support at lower cadences. It also responds a fraction quicker at the pedals, and delivers more overrun power when ratcheting the pedals over technical features up a climb. Despite the musclier performance, we’ve had excellent results in terms of range, with the Bosch motor regularly achieving more miles and elevation over EP8. Furthermore, the range estimation is more accurate in our experience too.
On top of that, you can’t tune the Bosch motor like you can with EP8 – there’s no fancy app, and the stock assist settings aren’t adjustable – what you see is what you get.
The downside for Bosch is that its display options leave a lot to be desired. The Kiox head unit has a nice colour screen with plenty of useful data on it, but we’re not sold on the magnetic attachment and the fact that the motor won’t turn on without the head unit. The Purion controller is vastly simpler and easy to read, but it looks cheap and it’s bulky, making it an awkward fit with brake and dropper levers. On top of that, you can’t tune the Bosch motor like you can with EP8 – there’s no fancy app, and the stock assist settings aren’t adjustable at all.
Still, the performance in the adaptive E-MTB mode is excellent, with smooth and flexible power delivery, and riders wanting plenty of grunt will certainly dig the Bosch motor. Occasionally it can feel a little peakier compared to EP8, but for the most part both motors are easy to get used to within a few rides.
It’s worth noting that Bosch motor is only compatible with Bosch battery options though. You also need a special key to release the battery from the frame, which we’re not fans of, at least for a mountain bike anyway. In comparison, Shimano motors can be paired with third party batteries, and that opens up greater flexibility for bike designers (see the Orbea Rise and Pivot Shuttle for example).
Specialized 2.2 (Brose Mag S)
The Brose Mag S motor has been used in the Specialized Levo and Kenevo since 2018, though it was recently updated for the release of the new Levo. Simply named by Specialized as the ‘2.2’, the motor continues to offer 90Nm of peak torque, and externally it has the same mounting points and overall shape. It’s considerably bulkier than Shimano EP8, dominating the Levo’s frame profile while also putting limitations on rear wheel clearance. Indeed Specialized actually built the new Levo around a mullet setup with a 27.5in rear wheel, in order to shorten the chainstays.
5Nm doesn’t sound like much on paper, but on the trail the Levo’s 2.2 motor is noticeably musclier than Shimano EP8, particularly at the extreme ends of the cadence spectrum. The belt-driven design is also a touch quieter when pedalling, and there’s no clacking noise either. Power delivery is immediately intuitive thanks to the new MasterMind firmware that Specialized developed specifically for the 2.2 motor, which reduces power spikes from rapid changes in crank speed and pedal pressure. The way the 2.2 motor smooths out un-smooth rider input is very impressive, giving it the most natural feel on the trail of any full-power motor we’ve tested.
However, you do pay for all that refinement and integration.
A downside of the 2.2 motor is that it is noticeably draggy above the 25km/h cutoff though – something we experienced during back-to-back between the Levo and Canyon Spectral:ON. If you’re sprinting at speed, the Levo feels sticky and lazy in comparison to the drag-free EP8 motor.
Overall it is a very refined system though. Specialized’s Mission Control app continues to be the market leader in terms of connectivity, tuning options and user-friendliness. The MasterMind TCU head unit on the top tube is also as good as it gets, with a sharp and clear, but unobtrusive display that reduces clutter on the handlebars. You can display way more metrics on it too, and battery is usefully displayed as a percentage.
However, you do pay for all that refinement and integration. The cheapest Specialized Levo is the Expert model, which sells for just shy of $16K. Wowzers! In comparison, you can get a Polygon Mt Bromo N8 with a Shimano EP8 motor for $7,899 AUD. And in terms of backup service and support, the fact that there are far more Shimano dealers than there are Specialized dealers may also be preferable for some riders.
What other bikes are coming with Shimano EP8?
Indeed Shimano EP8 is starting to become available across quite a wide range of bikes at various price points. In addition to those we’ve tested, you’ll be able to find Shimano EP8 on the Santa Cruz Bullit & Heckler, Marin Alpine Trail E2, the Commencal Meta Power, YT Decoy, Pivot Shuttle and Mondraker Dusk.
The fact that the EP8 motor uses the same mounting points as the old E8000 motor means there are a few bikes out there that we’re anticipating will be updated with the new motor – like the Norco Sight VLT and Range VLT.
Another bike that features Shimano EP8 is the new Orbea Rise. It’s a little different though, with Orbea detuning the motor’s power and assistance to improve efficiency so it can use a smaller and lighter 360Wh battery. Along with the svelte carbon frame, that helps to reduce the total bike weight to as low as 16.2kg, creating a potentially worthy adversary to the Specialized Levo SL. As to how the de-tuned EP8 motor performs? Stay tuned, as we’ll have an Orbea Rise test bike arriving very soon.
Over the past six months of riding, the Shimano EP8 motor has really impressed us with just how much punch it delivers from such a lightweight and compact package. It’s clear why this motor is becoming popular with so many bike brands, given the flexibility it offers frame designers, particularly with the variety of battery options on offer.
The touch points are all up to typical Shimano standards of quality, though we would like to see improvements to the functionality of the display unit, notably having battery life shown as a percentage. And we certainly wouldn’t be upset if Shimano could quieten down the clacking noise.
Still, that clutch design means it is impressively drag-free beyond the cutoff point. And compared to E8000, the new EP8 motor is considerably more powerful on the trail, whilst retaining the smooth and intuitive delivery that we’ve always dug about Shimano’s drive units. The updated Trail mode is brilliant, and the option to fine-tune each assist mode is a welcome feature for achieving the desired feel while maximising range. Along with the fault-free performance we’ve experienced so far, we’d have no hesitation in recommending a bike built around Shimano EP8 – this is a high quality and well-rounded e-MTB system.