Tern HSD S+ Folding Electric Bike
Enormously useful yet surprisingly small—the Tern HSD S+ folding electric bike is shorter than a standard bicycle, yet carries a whole lot of cargo, while offering a ride so easy, it shifts itself.
Key Details
- Next-generation Bosch® Performance Line motor with Intuvia display delivers pedal assist up to 20 mph, helping you carry groceries and tackle steep hills, without the sweat
- enviolo AUTOMATiQ shifter and Sport 380 internally geared rear hub offer effortless, stepless automatic shifting across a wide gear ratio range of 380%
- Perfect for longer rides, the Bosch PowerPack 500 battery offers a range of up to 74 mi., depending on conditions and assist settings
- Custom Suntour suspension fork smooths out rough roads with 70mm of travel
- Cane Creek® Thudbuster ST suspension seatpost offers additional comfort without sacrificing performance or control; tunable to match your weight and riding preferences
- Magura® MT4 hydraulic disc brakes deliver consistent, powerful braking, even in wet conditions
- Gates Carbon Drive® CDX belt lasts more than twice as long as a typical chain and works without lubrication, meaning no greasy, dirty buildup to get on your hands or clothes
- ABUS® keyed-alike frame lock offers light security for quick stops and can be matched to use the same keys as a higher-security ABUS lock (not included)
- Fits riders from 4'11" to 6'5" (150 to 195 cm)
- Fits one Thule® Yepp Maxi, Yepp Nexxt Maxi or Bobike® GO Maxi child seat—no adapters needed (child seats not included)
- NOTE: Specs and images are subject to change based on component availability
Imported.
- 1 year of free adjustments (see more below)
- In-store bike assembly
- Pickup in store or curbside
- Bike experts available at 170+ bike shops
- 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)
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
| Best Use | Urban Cycling |
|---|---|
| E-Bike Classification | Class 1: pedal assist up to 20 mph |
| Motor | Bosch Performance Line (Gen 3) |
| Motor Type | Mid-Drive |
| Motor Torque (Nm) | 65 |
| Battery Type | Lithium Ion |
| Battery Capacity (Wh) | 500 watt hours |
| Battery Removable | Yes |
| Charge Time (hrs) | 2.5-4.5 hours |
| Pedal Assist Range | 32-74 miles |
| Frame | 6061 aluminum |
| Foldable | Yes |
| Step-Through | Yes |
| Bike Suspension | Front Suspension |
| Fork | Suntour custom for Tern |
| Fork Travel | 70 millimeters |
| Crankset | Tern HSD custom |
| Bottom Bracket | Motor integrated |
| Shifters | enviolo AUTOMATiQ |
| Rear Cogs | Gates CDX, precision CNC machined cog |
| Internally Geared | Yes |
| Brake Type | Hydraulic Disc Brake |
| Brakes | Magura MT-4 hydraulic disc |
| Brake Levers | Magura hydraulic |
| Rims | Tern Atlas H, Cargo |
| Front Hub | Novatec, thru axle, sealed bearings |
| Rear Hub | enviolo Sport 380 |
| Wheel Size | 20 inches |
| Tires | Schwalbe Big Ben 20 x 2.2 in. (55-406mm), RaceGuard Puncture Protection |
| Tire Width | 2.2 inches |
| Handlebar Shape | Flat Bar |
| Handlebar | Tern Sweep, 6061-AL, Tern Andros Adapted |
| Stem | Tern Physis 3D with Andros Stem |
| Seat Post | Cane Creek Thudbuster ST, Tern Telescope, 34.9/30.9mm |
| Saddle | Tern HSD |
| Pedals | Urban platform with nonslip surface, sealed bearings |
| Headset | Tern Flux Pro Taper, 1.5 in., angular contact bearings |
| Chain | Gates Carbon Drive CDX Belt |
| Belt Drive | Yes |
| Weight | 58 lbs. 11.2 oz. |
| Bike Weight | Bike weight is based on median size, as sold, or the average of two median sizes. |
| Gender | Unisex |
| One Size | |
|---|---|
| Height Range | 4'11''-6'5'' |
How we measure bikes
- 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.
- Reach Reach is the horizontal distance from the center of the cranks to the center of the head tube, measured at head tube level.
- 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.
- 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.
- 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.
- Head Tube Length Head Tube Length is measured from the bottom to the top of the head tube.
- Head Tube Angle Head Tube Angle is the acute angle between the head tube and the ground (measured towards the rear of the bike)
- Seat Tube Angle Seat Tube Angle is the acute angle between the seat tube and the ground (measured towards the rear of the bike).
- Bottom Bracket Height Bottom Bracket Height is a measurement taken vertically from the ground up to the center of the cranks.
- Wheelbase Wheelbase is the measurement from the center of the front axle to the center of the rear axle.
- Chainstay Length Chainstay Length is the measurement from the center of the cranks to the center of the rear axle.
- 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.
Review this Product
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smooth ride; doesn’t register the downhill
Pros: easy to store; fits in crosstrek; comfy ride due to suspension; still able to shift manually (hold down i twice); easy to attach child seat; adjustable seat post and handlebars means that more than one person in your household could potentially ride it Cons: auto shifting doesn’t register the downhill so bike will stay in a low gear and you will bottom out (on Seattle hills, at least) unless you switch to manual gear. Overall fun to ride; not sure if I would recommend unless Tern can solve the downhill issue; at this price point I would have thought that this wouldn’t be an issue at all. (Not an issue if you live in a flatter area). Absolutely test ride before you purchase; I wasn’t able to due to covid restrictions (purchased from my LBS) and May have made a different choice if I had in fact test ridden.
Love This Bike
This bike is the fun of a single speed with the power of a geared bike and a motor. It’s very comfortable, my kids can hop on the back and we can carry so much stuff. I store it on its end in a closet and there is basically no maintenance with the belt drive and Enviolo hub. I live in Seattle, like another reviewer, but I’m not having a problem bottoming out when going down hills. I did have a learning curve for setting my cadence (revolutions per min). If I set it too high or low it can feel like being in the wrong gear. It’s easy to adjust and after finding my preference (around 80) I can just enjoy the ride and let the bike do the shifting. I also learned to calibrated the hub before my initial ride. It’s a simple process if you look on Enviolo’s site for calibrating Automatiq with Bosch Intuvia display. The REI staff did a great job getting the bike setup and helping with Tern accessories. Thank you Tern and REI!
Impressive!
This e-bike is impressive... Light weight when compared to other e-bikes. I can easily ride another person around and/or haul packages... It's all around fun. Has all of the latest technology. Impressive!
Bought this for Santa Barbara 2nd home
This bike is fantastic. I have driven my truck once since we got the bike it is a serious replacement. The battery lasts for about 40-50 miles of beach/hills cruising. The build quality is high. The motor is powerful and the belt drive is silent. The shifting is very smooth. I test rode and decided within 2 minutes I was buying one. Grins ear to ear and you will feel like a kid again. Great investment.
I HATE AUTOMATIC SHIFTING!
I bought this version of the HSD because I'm heavy and I carry a lot of cargo, so I wanted the most powerful motor. I liked the idea of a belt drive, too. Because of stores being closed due to Covid-19 I didn't get to ride this before I bought it and now I know- I HATE AUTOMATIC SHIFTING! I refuse to buy an Active Line motor on the other HSDs. I refuse to buy an old CV motor on the GSD, so guess what? Tern has lost my business. Oh- the Cane Creek seatpost comes with the #5 elastomer that is rated for riders up to 200 lbs, and they are out of stock of #7 elastomers, so I can't ride this bike anyway without risking damage to the suspension seatpost. Tern does not tell you about this limitation in their literature. This bike is going back.