Tern HSD S8i Electric Bike Review

Are you in the market for a low-maintenance electric bike or trying to understand the differences in Tern HSD electric bike models?

In this video and article, I’m going to be reviewing the Tern HSD S8i electric bike that utilizes a Bosch mid-drive motor, Shimano internally geared hub and a Gates belt drive. This is a great bike for many but a lot of bike shops don’t cover the fine details of this internal hub or motor so today we are going to be doing just that! 

Earlier this year, I did an overview of the Tern HSD electric bike which you should check out here. I have also done a pretty comprehensive Tern HSD P9 review and have found this is a wonderful e-bike that fits in many people’s lives. Make sure to check out the links for those articles and videos.

Tern HSD S8i Electric Bike

What Makes the Tern HSD Special?

Before we go too deep into the S8i HSD model, some of the key features of the Tern HSD in general for me:

  • One size fits most. You can easily change the fit and handling of this bike with the adjustable Andros stem or two-stage seatpost. This also allows you to share this bike between multiple height people.
  • Low step-through for easy on and off. These bikes weigh 50lbs and it is nice to be able to step off the bike instead of leaning the bike and swinging your leg over
  • The bike is capable but not a huge cargo bike. You can get a good amount of groceries on this bike with the additional accessories like the Cargo Hold 37 bags or front rack options BUT it isn’t a huge cargo bike designed to carry 400+ pounds or 2 kids on the back. Instead, you can carry about 130 lbs on the back or one decent-sized child. 
  • The depth of the available Tern accessories makes this one of my favorite electric bikes because you can make it whatever YOU want it to be. 
Tern HSD Frame

Tern HSD S8i Electric Bike Details

Retail on this bike is $3800. You get an internally geared Shimano hub, gates belt, and upgraded Magura brakes over the $3200 P9 model.

The internally geared hub is good, but it isn’t specifically designed for cargo hauling or shifting under load. The biggest benefit for this system is that you can shift at a stop and that the gears are all inside the hub so you don’t have a derailleur hanging down to get beat up or dirty.

Shimano Internally Geared Hub Note: You must pause your pedals when shifting this internal hub. It doesn’t handle the torque of the bosch motor and your pedaling well when shifting. If you live in a hilly area, this may not be the bike for you due to this.

The gates belt drive is super nice and quiet, it helps keep a cleaner bike as there is no lube to fuss with. To adjust the tension the gates belt drive is very easy with the help of an app to hear the sound of the snap in the belt. I like to check after 100 miles when the bike is new and then every 3-400 miles after that.

Tern HSD S8i with Bosch Active Line Motor

Is the Tern HSD S8i for you?

There are a few people I think the S8i is for:

  1. You want relatively maintenance-free biking. No chain to lube. Just keep the tires inflated and the battery charged.
  2. Newer or inexperienced riders – the internal hub system is very nice for people not used to shifting or remembering to shift before a stop. 
  3. The gates belt drive is sexy. I’m based in Colorado where the Gates US office is. There are many people that swear by the gates belt drive and love the look of it.

Who is it not for? 

  1. Someone that needs a lot of assistance from the motor. Check out the new P9 Performance model
  2. Someone that is going to be climbing lots of hills, again check out the P9 Performance model
  3. Someone that knows how to shift and doesn’t need anything fancy, check out the standard P9 non-performance model and save some money. 

Other Tern HSD Electric Bike Resources

Disclaimer: First off, since writing this article I have gone to work for Tern Bicycles. This article was written before this, and is in no way biased. If anything – I went to work for them because they make such wonderful bikes!!

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