Tern  GSD S10 Folding Electric Bike

This item is not eligible for Member Coupons.
Color: Tabasco
Size: One Size
Heads up! Bikes usually take 1-2 additional days to assemble but can take longer during busy periods. We'll email you when yours is ready.

Members get an estimated $449.90 (10%) back on this item as a part of your annual .

Members get an estimated $449.90 (10%) 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.


  • 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 on e-bikes
  • 20% off shop services
  • Free tubes with purchase of flat tire repair (Co-op Cycles brand tubes only; tube must be installed at time of purchase)
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.

UL2849 certified
View the Tern GSD Product LineView all Tern Electric Cargo Bikes

Technical Specs

Item #187356
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.

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