HSD Gen 3 basics article banner image, with HSD S9i

HSD Gen 3 Electric Cargo Bike: The Basics

This article refers to Tern HSD Gen 3 cargo bikes. Click here if you have an HSD Gen 2.

Thank you for choosing Tern, and congratulations on your new HSD! We're excited to be part of your journey. This article introduces the basic functions of both HSD P-Class and S-Class models. But if you'd rather watch than read, you can also check out the HSD Gen 3 Owner Briefing video playlist on YouTube.

Contents

 1. Introduction

The HSD Gen 3 lineup includes both P-Class and S-Class models. Both are equally fun to ride and built for everyday utility, but there are a few important technical differences. Unless otherwise indicated, the information below applies to all models.

2. Adjusting the bike fit

Your HSD comes with an adjustable stem and telescopic seatpost that help you find your optimal riding position.

2.1. Adjusting the saddle height

The saddle height is adjusted by opening the quick-release lever, setting the seatpost to your preferred height, and closing the lever again to secure it. For your safety, please ensure that you stay within the minimum insertion point marked on the seatpost.

To adjust the tightness of the quick-release, open the lever and then twist the clamp screw nut. The quick-release should be loose enough to open the lever, but tight enough to prevent the seatpost from sliding down. Please remember to properly adjust and close the quick-release to prevent injury.

2.2. Adjusting the Andros Stem

The HSD also comes with the Andros Stem, which helps you adjust the height, angle, and orientation of your handlebar. To adjust the Andros, raise one lever at a time, adjust the stem and handlebar to your desired position, and finally, close both levers firmly.

2.3. Adjusting the suspension seatpost

For S-Class owners, your bike is equipped with the shock-absorbing Cane Creek Thudbuster Suspension Seatpost for an extra comfortable ride. To optimize your comfort, it’s possible to switch out the inner elastomer in the seatpost for one that’s more suitable for your body weight. For more information, visit Cane Creek’s website.

3. Important bike parts & functions

Your HSD comes with a shifter that allows you to control the speed and pedaling resistance. How you shift gears depends on which HSD model you have.

3.1. Changing gears

3.1.1. HSD S9i/S9i Sport

The 3X3 NINE gearbox on the HSD S9i and S9i Sport supports Bosch eShift, allowing fast, precise electronic gear changes through a wireless connection that eliminates traditional shift cables for a cleaner cockpit and consistent shifting performance.

One of its key features is automatic downshift, which shifts the bike to a preselected starting gear whenever the bike comes to a stop, making it easier to start again, especially when carrying cargo or passengers.

By default, the gearbox shifts to 4th gear, but you can customize the starting gear using the 3X3 Servicetool on a computer. After connecting to the bike via Bluetooth, you can select your preferred starting gear in the AutoDownShift menu, disconnect to save the setting, and reconnect at any time to verify the change.

More on this: Customizing 3X3 NINE on the Tern HSD S9i & S9i Sport

3.1.2. HSD P10e/P10e Sport

The TRP E.A.S.I. drivetrain on the HSD P10e and P10e Sport combines a traditional derailleur with Bosch eShift to provide automatic or manual gear shifting based on your riding preference.

In Manual shifting mode, you shift gears yourself, while Automatic shifting mode continuously adjusts gears to maintain your selected cadence as your speed, terrain, and pedaling effort change. You can customize your preferred cadence through the Purion 200 display and switch between Automatic and Manual modes at any time using the Mode button on the TRP shifter, allowing the drivetrain to be tailored to different riding styles and conditions.

More on this: Customizing TRP E.A.S.I. on the Tern HSD P10e & P10e Sport

3.2. Braking

All HSD models have front and rear hydraulic disc brakes for excellent stopping power.

When looking at your handlebar from the rider’s position, the rear brake lever is on the right, and the front brake lever is on the left. In a few countries, this orientation may be reversed. Before going for a ride, we recommend double-checking each lever separately just to be sure.

Please apply even pressure to both brake levers when stopping. Braking suddenly can result in dangerous situations, particularly in wet or slippery conditions.

Due to their heavy use, brake pads may be the first components of your HSD that you need to replace. So, keep a good eye on your brake pads, especially if you regularly make steep descents.

3.3. Adjusting the suspension fork

Your HSD comes with a shock-absorbing Suntour front suspension fork that has two adjusters: a Speed Lock adjuster and a Preload adjuster.

To enable suspension, turn the Speed Lock adjuster to the open position. To disable suspension, turn the Speed Lock adjuster to the lock position. The Preload adjuster lets you adjust the hardness or softness of your ride. Turn the Preload adjuster clockwise for a harder ride or turn it counter-clockwise for a softer one.

 4. Bosch Smart System

4.1. The HSD is a pedelec

Before you venture out into the world with your HSD, we’d like to remind you that the HSD is a pedal-assisted electric bicycle—pedelec for short. This means that the Bosch motor will only provide power while you pedal. The motor will stop providing power once your local speed limit has been reached.

4.2. Bosch Smart System basics

The HSD Gen 3 is outfitted with the Bosch Smart System, which links the motor, display, battery, control unit, and the eBike Flow App to create a personalized riding experience.

4.3. Control units

Your HSD comes with either the Purion 200 or LED Remote. These control units let you operate the motor system, switch the integrated lights on or off, adjust personalised settings, connect your bike to the eBike Flow App, and more.

4.3.1. Turning the bike on/off

To turn the motor system on and off, press the power button on your control unit. The system will automatically turn itself off if you don’t move the bike or press any buttons on the control unit for 10 minutes. It’s best to turn it on and off when standing next to or straddling the bike. Please never do it while you’re applying pressure to the pedals.

4.3.2. Assistance levels

You can select how much assistance the motor provides at any given time during your ride. To switch between the assistance levels—Eco, Tour, Auto, and Turbo—you can press the plus (+) or minus (-) button on the control unit.

When you switch between assistance levels, the control unit indicates with colors which level you are in. Green is for Eco, blue is for Tour, purple is for Auto, and red is for Turbo. Auto is a Bosch Smart System level that automatically adjusts how much assistance the motor provides based on your riding conditions.

4.4. Display

4.4.1. P-Class bikes

The P-Class bikes come with the Purion 200, a two-in-one display and control unit.

It shows the battery level, speed, and your current e-assist level. To view more information, press the left and right arrow buttons. Sometimes, you may receive a notification about your e-bike system and road safety. After reading the notification, you press the selection button (♦) to delete the message. It is not possible to remove the display from the bike.

Learn more: Bosch Purion 200 Display Settings for Tern Bikes

4.4.2. S-Class bikes

The S-Class bikes come with a Bosch Kiox 300 display, which is full of helpful information divided into different categories.

You can scroll through the categories by pressing the left and right arrow buttons on the LED Remote to view details about your speed, trip, range, and more. If you’d like to see more information within each category, press the selection button.

You also may receive notifications about your e-bike system and road safety. To close the notification, press the selection button (♦) on the LED Remote after reading it.

If eBike Lock is enabled in the eBike Flow App, removing the display automatically activates the lock. To reinstall it, align the display with the mount, then gently push it down and toward the rear until it clicks into place. Reinstalling the Kiox 300 automatically disables eBike Lock.

Learn more: Bosch Kiox 300 Display Settings for Tern Bikes

Safety Tip

To prevent theft or tampering, we highly recommend that riders remove their display when leaving their bike unattended.

4.5. Walk assist

The Bosch Smart System has a Walk Assist function that lets you push your bike with less effort. This feature comes in especially handy when you need to push your bike up a steep hill or ramp.

Before activating Walk Assist, always make sure the bike is in one of the four e-assist modes. If the motor system is set to “Off,” you won’t be able to activate it.

To activate Walk Assist, press the (-) button on your control unit for more than 1 second and keep it pressed. Then either walk the bike forward, push the bike backward, or tilt the bike sideways to engage this function. To stop using Walk Assist, just stop holding the (-) button and press the (+) button or wait for 10 seconds.

Good to know: The speed of this function depends on which gear you’re in. The higher the gear, the more Walk Assist you’ll get.

4.6. Integrated lighting system

The HSD Gen 3 bikes have an integrated lighting system that connects the front and rear lights to your e-bike system.

To turn the lights on, slide the switch at the rear of your front light to the right and press the (+) button on your LED Remote or Purion 200 for three seconds. To turn the lights off, press the (+) button again for three seconds. You don’t need to change the position of the switch on the rear of the front light.
 

Safety Tip

Always keep your lights on while riding, and adjust the front light beam angle downward to avoid blinding oncoming traffic.

4.7. Battery

Your HSD bike includes a Bosch battery and a Bosch battery charger. It is possible to charge the battery either on or off the bike.

Safety Tip

Before you charge the battery, always make sure the motor system is turned off and the battery is completely dry. Ensure charging is performed on a fireproof surface in a well-ventilated area.

4.7.1. Charging the battery ON the bike

To charge the battery on the bike, open the rubber lid on the top tube, plug the connector into the socket, and connect the connector to an electric outlet.

4.7.2. Charging the battery OFF the bike

To charge the battery off the bike, insert the key into the lock, turn, lift, and pull out the battery. Once the battery is off the bike, plug the connector into the socket, and plug the charger into an electric outlet. To insert the battery, place it on the battery mount and push the battery until you hear a click.

4.8. eBike Flow App

The eBike Flow App is the control center for the Bosch Smart System. You can use it to enable anti-theft features, customize the motor’s performance and riding modes, install the latest software updates, and a lot more. Once you’ve downloaded the app, it will give you step-by-step instructions on how to connect it to your bike. For the latest updates, please refer to the Bosch eBike Systems website.

Flow+ is an optional subscription that unlocks premium features in the eBike Flow App, such as extended navigation and ride statistics. On bikes with a ConnectModule, it also includes eBike Alarm, GPS Tracking, and battery status monitoring. Bikes with a ConnectModule include a free 12-month trial. Bikes without one come with a free 1-month trial.

After the free trial ends, Flow+ automatically renews as a paid subscription. You can choose monthly or yearly billing. Please note that subscription pricing varies by country. You can cancel at any time before the next billing cycle. Some of the key Flow+ features are explained in the following sections.

More on this: eBike Flow App Basic Settings for Tern Bikes

5. Securing your bike

Thanks to the Bosch Smart System, the HSD has anti-theft features that will put your mind at ease when it’s time to park your bike. These digital security features are designed to complement a physical bike lock, adding an extra layer of protection while a physical lock secures the bike to something sturdy.

Tip: After activating the following functions in the eBike Flow App, we recommend checking the settings to make sure all security functions are turned on.

5.1. Activating the eBike Lock & Alarm

You can activate the eBike Lock function in the eBike Flow App. Once eBike Lock is activated, the motor support will automatically lock when you turn off the system or leave the bike stationary without pressing any buttons for 10 minutes. If your bike ever gets stolen, the thief won’t be able to get any power assistance from the motor.

For S-Class bikes equipped with the Bosch ConnectModule, activating the eBike Lock also activates eBike Alarm.

If someone tampers with or significantly moves your bike, an alarm will sound and a notification will be sent to your connected phone, allowing you to track your bike through the eBike Flow App. The locked motor will not provide power assistance.

Because eBike Lock and Alarm use Bluetooth pairing with your smartphone, making it the key to your bike’s motor system, you cannot turn on the system unless your phone is nearby and Bluetooth is turned on.

Learn more: GPS Tracking on Tern Bikes

5.2. Locking the frame lock

Your HSD has a frame lock located at the top of the rear wheel. The key stays in the lock after unlocking and while riding. To engage the lock, turn the key and slide down the knob until you hear a click. Then pull the key out. Please keep in mind that you can't remove the key unless the frame lock is locked, so always make sure the lock is firmly closed before attempting to remove the key.

6. Frame & battery keys

The key to your frame lock matches the one for your Bosch battery, so you can use the same key to remove the battery and (un)lock the frame lock.

The key stays in the frame lock after unlocking (while you are riding), so it’s always easy to find and won’t get lost. For safekeeping, we recommend emailing the key serial number to yourself and registering your keys with the lock manufacturer. They will need this serial number to order the replacement key for you. In addition, when you sign up for Tern Care, we recommend entering your key serial number as part of the registration process.

7. Flat-folding your bike

The HSD’s cockpit can be folded in such a way that it fits into an SUV and can be taken on public transport. It might take some practice, but once you’ve memorized the following steps, you’ll fold your HSD in no time.

  1. Open both Andros Stem levers.
  2. Angle the stem upward so that it’s in line with the handlepost.
  3. Properly close both Andros Stem levers.
  4. Rotate the handlebar 180°.
  5. Slide the security knob on the handlepost upward, and pull down the lever.
  6. Fold the handlepost down and secure it to the frame with the rubber strap.
  7. Lower the saddle.

When you close and open the lever, be sure that the lever feels stiff—but not too stiff. The stiffness is just right if you need to firmly pull the lever to open it and feel some resistance when you close it with your hand. Not correctly closing or adjusting the lever can pose a risk of injury.

8. Vertical parking and rolling

Your HSD is not only easy to ride, but also easy to store. Vertical Parking helps you fit your HSD in narrower spaces (including an elevator) and make room for other stuff. This is how you park and roll your HSD vertically:

  1. Stand on either side of your bike and hold the handlebar with both hands. 
  2. Apply the rear brake and walk backward until the bike stands up. Don’t pull the bike backward; just focus on walking.
  3. Ensure that all of the contact points on the rear of the bike are in contact with the floor and that the bike is parked on a flat, even surface. 
  4. To get your bike back on both wheels, hold the handlebars, apply the rear brake, and walk forward until the front wheel makes contact with the ground. For your safety, please do not catch the bike as it comes down, but just walk forward with control instead.

You can also roll your HSD when the bike is in a vertical position, but please make sure you’re not holding the rear brake when rolling the bike forward.

9. Daily riding checklist

Safety should always come first. To ensure that everything on your bike is secured and functioning properly,  we recommend you do the daily ABCQ test to check your air pressure, brakes, chain, quick release, and more.

Go through the list: What to Check Before Each Bike Ride

10. Accessories

With a max gross vehicle weight of 190 kg (419 lb) and a rear rack rating of 80 kg (176 lb), the HSD is a tough everyday bike made to carry both passengers and cargo. Check out the following guides for suggested accessories and setups:

11. Ready for the ride?

We hope that this list of basic information can help you get started. If you’d like to have support from fellow HSD riders, we invite you to join our Tern HSD Facebook Group, where you can share your experiences with other HSD enthusiasts.

Happy e-biking!