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2020

Powerfly 4

/
Model 29451

Powerfly 4 is our most affordable electric mountain bike. It's built with parts that hold up, like a dependable 9-speed Shimano drive train, a 120 mm SR Suntour fork and a powerful Bosch Performance CX motor. Plus, it features our user-friendly Removable Integrated Battery (RIB) system that's fully encased in the frame yet doesn't require tools for removal. This bike expands your boundaries and lets you travel to destinations that you never thought you'd reach on a mountain bike.

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It's right for you if...

You're sold on the e-bike revolution and want the capability and versatility of a mountain bike at a price that doesn't resemble the car you're trying to use less. You want bigger, better trail adventures and know that an e-MTB with the latest user-friendly tech is the best way to get them.

The tech you get

A lightweight and durable Alpha Platinum Aluminium frame that fully encases a long-range 500 Wh battery for sleek looks and protection on the trail, a Bosch Performance CX (250 W, 75 Nm) motor that assists up to 25 km/h, an ergonomic Bosch Purion controller, a Shimano drive train, a 120 mm SR Suntour XCR fork with lockout and hydraulic disc brakes. Plus, Smart Wheel Sizing means you'll get the fastest wheel that fits – 29˝ wheels on larger frames, 27.5˝ wheels on smaller frames.

The final word

Our most affordable electric mountain bike is equipped with performance parts, a high-end Bosch motor, powerful battery and intuitive controller for confidence and a fun boost on trails and roads.

favorite_borderWhy you'll love it

  1. Trek's Removable Integrated Battery (RIB) system looks great and is super user-friendly: it fully hides the battery in the frame for protection, makes it easy remove the battery without tools and lets you mount a water bottle cage
  2. This bike expands boundaries: the top-notch Bosch system is equally suited to commuting, recreation and a ridiculously fun time on the trails
  3. The Purion controller has Walk Assist and an intelligent eMTB mode that automatically delivers the right amount of power based on your terrain
  4. It's equipped with an external charging port for easy charging on or off the bike
  5. It rides like a trail bike because it is one: Powerfly is built according to Trek's trail heritage with mountain bike tech developed over decades of innovation


Features

Will my bike have a curved top tube?

Will my bike have a curved top tube?

Smaller frames (S) have a top tube that dips down as it approaches the seat tube. This design makes for a lower standover height, which is good for shorter riders because it allows them to straddle their bike more easily. The larger frames (M and ML) have a straight top tube because taller riders with longer legs typically don’t have the same issues with standover height.

New Bosch Performance Line CX

New Bosch Performance Line CX

The all-new Bosch Performance Line CX motor is lighter, smaller and quieter than previous versions, for cleaner integration and more nimble handling. It’s also more efficient so you can go further on a single battery charge. Use the intelligent eMTB mode to automatically adjust the amount of assist to match the terrain. It’s a set-and-forget mode that delivers just the right amount of power so you can focus on enjoying the ride.

Removable Integrated Battery

RIB is a one-piece battery and cover with a built-in handle that can easily be removed and re-installed in the frame with no tools and no hassle. It’s the most convenient way to remove your battery for transport, security or just easier charging.

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What is the range?

To see how far you can ride your electric mountain bike on a single charge, check out Bosch’s range calculator. We’ve auto-filled the variables for this bike model and the average rider, but you can make adjustments to get your most accurate estimate.

Calculate your range

Specifications

*spec applies to all sizes unless otherwise noted

Frameset
Frame Alpha Platinum Aluminium, Removable Integrated Battery (RIB), tapered head tube, Control Freak internal routing, Motor Armor, Boost148
Fork SR Suntour XCM 34, coil spring, preload, lockout, tapered steerer, 44 mm offset, Boost110, 15 mm thru axle, 120 mm travel
Max compatible fork travel 120mm (XS & S: 100mm)
Wheels
Front wheel NA
Rear wheel NA
Front hub Formula DC-511, 6-bolt, Boost110, 15 mm thru axle
Rear hub Bontrager alloy, sealed bearing, alloy axle, 6-bolt, Shimano 8/9/10 freehub, Boost148, 12 mm thru axle
Rim Bontrager Connection, double-wall, 32-hole, 20 mm width, Presta valve
*Tyre Size: S
Bontrager XR3 Comp, wire bead, 30 tpi, 27.5x2.35"
Size: M , L , XL
Bontrager XR3 Comp, wire bead, 30 tpi, 29x2.30"
Max tyre size 29x2.60" or 27.5x2.8" (XS & S: 27.5x2.60")
Drivetrain
Shifter Shimano Altus M2010, 9-speed
Rear derailleur Shimano Acera M3000, Shadow design, long cage
Crank FSA 310, 15T w/chain guard, 170 mm length
Cassette Shimano HG200, 11-36, 9-speed
Chain KMC E9S, 9-speed
Pedal VP-536 nylon platform
Components
Saddle Bontrager Arvada, steel rails, 138 mm width
*Seatpost Size: S
Bontrager alloy, 31.6 mm, 12 mm offset, 330 mm length
Size: M
Bontrager alloy, 31.6 mm, 12 mm offset, 360 mm length
Size: L , XL
Bontrager alloy, 31.6 mm, 12 mm offset, 400 mm length
Handlebar Bontrager alloy, 31.8 mm, 15 mm rise, 720 mm width
Grips Bontrager XR Endurance Comp
*Stem Size: S , M
Bontrager alloy, 31.8 mm, Blendr-compatible, 7-degree, 60 mm length
Size: L
Bontrager alloy, 31.8 mm, Blendr-compatible, 7-degree, 70 mm length
Size: XL
Bontrager alloy, 31.8 mm, Blendr-compatible, 7-degree, 80 mm length
Head set FSA IS-2, 1-1/8" top, 1.5" bottom
Brake Tektro HD-M275 hydraulic disc
Brake rotor Tektro, 203 mm, 6-bolt
Accessories
Battery Bosch PowerTube, vertical, 500 wh
Charger Bosch compact 2A (100-240 V) charger
Controller Bosch Purion
Motor Bosch Performance CX, 250 Watt, 75 Nm, 25 km/h max assist
Weight
Weight M - 24.47 kg / 53.95 lbs (with tubes)
Weight limit This bike has a maximum total weight limit (combined weight of bicycle, rider and cargo) of 136 kg (300 lb).
We reserve the right to make changes to the product information contained on this site at any time without notice, including with respect to equipment, specifications, models, colors, and materials.
Bike and frame weights are based on Trek pre-production painted frames at the time of publication. Weights may vary in final production.

Sizing & fit

Proper bike fit is essential for best performance and comfort. Any size and geometry measurements shown on trekbikes.com are for general comparison purposes only. To find your perfect fit, visit an authorised Trek retailer, where an expert skilled at sizing will help you find the appropriate bike and size for your individual needs.

 

Rider Height

Inseam

All measurements provided in cm unless otherwise stated.

Frame size number Frame size letter Wheel size A — Seat tube Effective seat tube angle C — Head tube length D — Head angle E — Effective top tube F — Bottom bracket height G — Bottom bracket drop H — Chainstay length I — Offset J — Trail K — Wheelbase L — Standover M — Frame reach N — Frame stack Stem length
15.5 S 27.5" 39.4 71.5° 13 67.6° 59.8 30.7 4.9 45.5 4.2 10.1 112.5 72.1 39 62.3 5
17.5 M 29" 41.9 71.7° 13 67.7° 61.7 32.4 4.9 45.5 5.1 9.8 115.5 79.4 40.6 63.9 6
19.5 L 29" 47 71.7° 14 67.7° 64.1 32.4 5 45.5 5.1 9.8 118 75.8 42.7 64.8 7
21.5 XL 29" 52.1 71.7° 16 67.7° 67.2 32.4 5 45.5 5.1 9.8 121.2 76.8 45.2 66.7 8

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