Tern GSD S10 Folding Electric Bike

Color: Tabasco
Size: One Size
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Members get an estimated $539.90 back on this item as a part of your annual .

Members get an estimated $539.90 back on this item.
To buy,  sign in as an REI Co-op Member or join now.

Built to carry 2 kids plus groceries—or a whole lot of cargo—and featuring dual-battery technology that's ready to ride all day, the Tern GSD S10 electric bike just might be able to replace your car.

  • Features

    • The same length as a regular bike, the GSD S10 is incredibly easy to own and use, thanks to space-saving features like FlatFold and Vertical Parking
    • With FlatFold, the handlebar and stem fold down next to the frame, and the seat post telescopes all the way down, enabling the bike to fit in larger vehicles and tight spaces
    • Regular bikes take up a lot of floor space, but the GSD S10 parks vertically, so it takes up about as much space as a potted plant—perfect for city apartments and elevators
    • Bosch® Cargo Line Motor provides up to 85 Nm of torque and 400% support, making it easier to tackle big hills and ride with heavy loads
    • Shimano Deore shifting with Deore Shadow+ rear derailleur offers crisp, reliable changes across the wide-range 10-speed cassette
    • Adjustable cockpit comfortably fits riders 4'11" to 6'5" (150 to 195 cm)
    • Super tough Atlas Lockstand™ automatically locks when engaged—just press a button on the handlebar to unlock
    • Heavy-duty frame-integrated rear rack and integrated lower decks offer plenty of kid and cargo capacity—this bike handles up to a 440 lb. (200 kg) Maximum Gross Vehicle Weight
    • Magura® MT5 eSTOP 4-piston hydraulic disc brakes deliver powerful and responsive braking in all conditions
    • Always-on RearStop™ brake light helps you signal stops
    • Integrated Abus® wheel lock is keyed-alike with the battery
    • Upgraded Atlas wheels feature custom CNC-machined hubs for extra strength and durability
    • Integrated Tern Valo direct head light provides 150 lumens (41 lux) to help you see and be seen
    • Compatible with a wide range of cargo- and passenger-carrying accessories (not included)
    • Fits up to 2 Thule® Yepp Maxi seats (not included) with no adapters needed
    • Specs and images are subject to change


    This e-bike comes with Coast to Coast Support, which includes:
    • 1 year of free adjustments (see more below)
    • In-store bike assembly
    • Pickup in store or curbside
    • Bike experts available at 170+ bike shops
    REI Co-op Members get more:
    • An additional year of free adjustments (2 total years; see below)
    • Free flat tire repairs (labor only; parts not included)
    • 20% off shop services
    More about our free adjustments:
    New bikes go through a normal break-in period, after which they should be readjusted. All electric bicycles sold at REI include free adjustments for the defined period (one year after purchase date for non-members, or two years for REI Co-op Members)—as many times as you need. Included: derailleur and brake adjustments, lateral wheel truing, hub and headset bearing adjustments, tire inflation, chain lubrication and e-bike firmware updates. Not included: replacement or installation of new components or accessories, any other services. Call your local REI Co-op Bike Shop for more information.

    View the Tern GSD Product LineView all Tern Electric Cargo Bikes
  • Technical Specs

    Best Use

    Urban Cycling

    E-Bike Classification

    Class 1: pedal assist up to 20 mph


    Bosch Cargo Line Motor

    Motor Type


    Motor Torque (Nm)

    85 Newton meters

    Battery Type

    Lithium Ion

    Battery Capacity (Wh)

    400 watt hours

    Battery Removable


    Charge Time (hrs)

    2.5-4 hours

    Pedal Assist Range

    26-53 miles


    6061 aluminum



    Bike Suspension

    Front Suspension


    Chromoly steerer; 32 mm stanchions

    Fork Travel

    70 millimeters


    6061 aluminum DH crankarm

    Bottom Bracket

    Motor Integrated


    Shimano Deore

    Rear Derailleur

    Shimano Deore Shadow+

    Rear Cogs

    10-speed 11-36T

    Number of Gears

    10 gear(s)

    Brake Type

    Hydraulic Disc Brake


    Magura MT5

    Brake Levers

    MT5 E-Stop, hydraulic, with brake sensor


    Tern Atlas, ultrawide 36 mm, dual reinforced joint

    Front Hub

    Tern Atlas, Boost thru axle, cargo-optimized design, sealed cartridge bearing

    Rear Hub

    Tern Atlas, Boost thru axle, Syntace X-12 standard, cargo-optimized design

    Wheel Size

    20 inches


    Front: Schwalbe Big Ben Plus 20 x 2.15 in. (55-406); rear: Schwalbe Super Moto-X 20 x 2.4 in. (62-406); both with Green Guard puncture protection and Reflex

    Tire Width

    2.4 inches

    2.15 inches

    Handlebar Shape

    Moustache Bar


    6061 aluminum


    Tern Andros, adjustable, forged construction, patented technology

    Seat Post

    Tern Telescope, 34.9/30.9 mm, 2014 aluminum, telescopic


    Tern GSD by Velo with rear handle


    Urban with nonslip surface, sealed bearings


    Tern Flux Pro Taper, 1.5 in., angular contact bearings, Physis integrated


    10 speed, DHT for eBike, GST corrosion-resistant coating


    74 lbs. 0.5 oz.

    Bike Weight

    Bike weight is based on median size, as sold, or the average of two median sizes.




    Contains recycled materials

  • Size Chart

    One Size
    Height Range4'11''-6'5''

    How we measure bikes

    1. Standover Height Standover Height is a measurement from the ground to the top of the top tube, measured at the midpoint of the top tube.
    2. Reach Reach is the horizontal distance from the center of the cranks to the center of the head tube, measured at head tube level.
    3. Stack Stack is the vertical distance from the center of the cranks to the center of the head tube, measured to the top of the head tube.
    4. Effective Top Tube Effective top tube is the distance from the center of the head tube to the center of the seat tube/seat post, measured parallel to the ground.
    5. Seat Tube Center to Top Seat Tube length is the measurement of the seat tube, from the center of the cranks to the top of the seat tube.
    6. Head Tube Length Head Tube Length is measured from the bottom to the top of the head tube.
    7. Head Tube Angle Head Tube Angle is the acute angle between the head tube and the ground (measured towards the rear of the bike)
    8. Seat Tube Angle Seat Tube Angle is the acute angle between the seat tube and the ground (measured towards the rear of the bike).
    9. Bottom Bracket Height Bottom Bracket Height is a measurement taken vertically from the ground up to the center of the cranks.
    10. Wheelbase Wheelbase is the measurement from the center of the front axle to the center of the rear axle.
    11. Chainstay Length Chainstay Length is the measurement from the center of the cranks to the center of the rear axle.
    12. Fork Offset Fork Offset, or rake, is the distance from the front axle to a line drawn parallel to the center of the head tube or steering axis.
  • Reviews
    7 reviews with an average rating of 4.7 out of 5 stars

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