Founded in 1921, Shimano is a Japanese brand that needs no introduction. Leader in bicycle transmission components, Shimano also excels in producing integrated and semi-integrated pedal assist systems (PAS).
e903TRN PRO
FUN TO THE UMPTEENTH DEGREE
e903TRN PRO is the Full Suspended eMTB with all-mountain geometry introduced for excitement-seeking riders. The Shimano EP8 pedalling assistance system guarantees downhill adrenaline and uphill efficiency. The system has a 630 Wh Shimano battery inside the frame, autonomously providing up to 85 Nm torque and 250 W maximum power.
JAPANESE PRECISION
PRECISION AND RELIABILITY
EP is Shimano’s top-of-the-range line of e-bike components. EP8 offers intuitive trail support with the feeling of riding a normal mountain bike.
CENTRAL MOTOR
The motor generating traction is positioned in the bottom bracket to increase power to the pedals more directly and forcefully. Like the solution with the motor in the hub, no power is generated when bike speed exceeds 25 km/h.
EVEN MORE POWER
The 85 Nm torque is one of the most powerful on the market today. It’s perfect for off-road use with very steep slopes and rough surfaces. The 85 Nm torque generated by the central motor is directly related to the force applied to the pedals.
OVERSIZED CHARGE CAPACITY
Significant charge capacity for long, confident rides with no worries about residual charge. When you add 630 Wh to leg power, you greatly expand your pedalling horizons.
LONG-LASTING PERFORMANCE
More battery capacity means greater total system weight. This compromise enhances both performance and duration.
ANT+ CONNECTIVITY
The system uses ANT+ to dialogue with third-party devices. This provides all kinds of additional information that can be displayed on the latest cyclocomputers, such as Garmin and Polar.
EFFECTIVE PUSH
The truly lightweight motor’s maximal 250 W of power boosts pedalling effectiveness. The motor engages following the power delivery curve based on how you use the bike. Cadence triggers fluid and effective power with no feeling of resistance.
MAKE ROOM FOR POWER
The motor positioned inside the lower bracket needs more space to deliver all its power. As a result, the pedal cranks are slightly farther apart, increasing the Q-factor to 177 mm.

S | M | L | ||
H | [Cm] | 40,0 | 42,0 | 46,0 |
L | [Cm] | 59,9 | 61,9 | 64,1 |
L1 | [Cm] | 46,0 | 46,0 | 46,0 |
H1 | [Cm] | 11,0 | 11,0 | 12,0 |
A | [°] | 75,0 | 75,0 | 75,0 |
A1 | [°] | 66,5 | 66,5 | 66,5 |
REACH | [mm] | 440 | 460 | 480 |
STACK | [mm] | 592 | 592 | 601 |

Frame
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Drivetrain
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Wheelset
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Drive system
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Fork
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Rear shock
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Handlebar
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Stem
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Headset
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Shifters
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Brakes
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Rotors
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Rear derailleur
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Crankset
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Cassette
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Chain
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Tires
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Saddle
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Seatmast
![]() The prices, specifications and photos shown in this catalog are not subject to any contractual obligation and may change during the season. |
The most frequently asked questions
The Shimano EP8 pedal assist system installed on the e903TRN PRO delivers power up to 25 km/h.
The system installed on the e903TRN PRO has a 630 Wh battery installed entirely inside the frame. The Shimano EP8 motor delivers maximum torque of 85 Nm with maximum power of 250 W.
Yes, the e903TRN PRO is a pedal-assisted e-MTB: this means that if you do not pedal, the motor will not activate and will not assist pedalling.
Maintenance is quite limited and simple. The Shimano EP8 system requires no particular maintenance: wash your bike like a normal bike, lubricate the chain and check wear on the brake pads. However, Wilier Triestina recommends you have it checked regularly at an official reseller to avoid mechanical issues.
Contact your local Wilier Triestina dealer or Shimano service centre.
We recommend wiping it with a soft cloth and mild soap, then drying it completely before use. Do not use compressed air during washing.
Both the motor and the battery are water resistant, so you can use it in muddy or wet conditions.
29" wheels with 110x15 front boost axle and 148x12 rear boost axle.
You will need special permission to take your e903TRN PRO on a plane. You should contact your airline before booking your ticket.