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Hilltopper | Horizon Electric Bike Conversion Kit (350W Motor)

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Hilltopper | Horizon Electric Bike Conversion Kit (350W Motor)


Zoom up the hardest hills and turn heads as you show off your new super powers. The powerful and compact 350W motor provides a speed of 20+ mph at the push of a button and the pedal assist system provides a steady 15 mph cruising speed with each pedal stroke (throttle is optimized for speed, PAS is optimized for greatest battery range).


New features this year include an easy to remove Hilltopper lithium battery with 25 to 50+ mile battery range, a battery lock, led battery gauge that tells you how much power you have left, disc brake compatible hub, a USB charging port for your phone, a thumb throttle that allows you to control how much power the motor gives you, an easy to install pedal sensor that gives you power with every pedal stroke, a lithium battery charger optimized to ensure a long battery, and a higher efficiency Hilltopper motor that gives more torque for energy used (this motor is more compact than the Sprinter and also 60% more powerful).


This is the original Hilltopper “Go Fast Now” kit, updated for 2024. Fast, with only the features you need. Rugged, with the battery range for long days. Awesome! 



20+ mph

25-50+ miles

350 Watts

36 Volt Front Wheel Drive

36 Volt 11.4 Ah Lithium-Ion

Pedal Assist & Throttle

Battery Gauge?

Battery Lock?

18 lbs

Free Shipping

Disc Brake Compatible



Your Wheel

Your wheel is customized to fit the wheel size of your bike. Stainless steel spokes are combined with a double wall rim. Nylon rim tape provides extra protection against flats. A complementary Kenda tire & tube is included to make installation easy (and save you money). The wheel is compatible with rim and disc brakes to give you as many options as possible.



At the center of things is a 36V Hilltopper 350 Watt Electric Motor in black. Small & compact with a high torque to size ratio, this motor provides a 20 mph top speed and higher with pedaling. Torque roughly doubles the average persons pedal power. Hilltopper motors are legendary for their long lifespan, typically outlasting your bike.



Motor is powered by a 36V 11.4 Ah Lithium Ion battery. Range of 25 - 40+ miles depending on how much you pedal and the terrain. Built in a rugged duraplastic case, this battery mounts on your downtube using the water bottle cage mounts. Or on a rear rack or in a basket. Battery has a LED gauge that tells you how much charge is left, plus a lock that keeps the battery safe and makes it easy to remove when you need to recharge. Very energy dense, with a lots of range for the battery size. The complete battery pack is 378(L) x 78(W) x 99(H) mm.


Variable Speed Throttle and Pedal Assist System (PAS)

Activates your super powers and allows you to control how much assist the motor gives you. Fits most handlebars (hybrid, mountain, cruiser, etc.). For drop bars (found on road bikes) please see FAQ for fit. Installs by sliding on, you must remove your grips first to install. Very easy to use and long lasting.



Charges your 36V battery in 4-5 hours. Optimized for Lithium-Ion chemistry, this charger ensures a long lifespan for your battery.


How to Install



Disc Brake Compatibility

Yes, all Hilltopper wheels are disc brake compatible with standard spacing and 6-bolt rotor attachment. All of our wheels are also rim brake compatible giving you the most options to fit your bike!

For instructions on how to install a rotor on your new Hilltopper, check out the following video:


What is a variable speed throttle? How do I make sure it will fit on my handlebars?

Our variable speed throttle is just one piece of our kits that allows the rider to control the amount of power fed to the motor - kind of like a gas pedal!

The throttle is a versatile piece that can be installed on your handlebars and adjusted to whatever suits you and your bicycle best. We recommend putting the throttle on the left, placing them between the handlebar grip and the brake/shifter levers.

The most common type of handlebars on the market today would be a flat or riser handlebar. Our throttle is specifically made to match these handlebars with its 22.2mm grip diameter.

While the throttle grip is too small to fit most road bikes, drop bars, and any other handlebars with uncommon geometries, there is a pretty simple workaround - a handle bob (a quick Google search should get you plenty of result) can be attached to any of these handlebars for a quick and easy install.

Check out our video on how to install the variable speed throttle!


How Far Can I Go (Battery Range)?

• 36V 2020 Sprinter battery has 10 - 20+ miles of range.

• 36V Universal Battery Replacement has 20 - 25+ miles of range.

• 36V 2020 Horizon battery has 25 - 50+ miles of range.

• 48V Summit battery has 25 - 40+ miles of range.

Mileage rates are based on a 170 pound rider on a 30 pound bike on a flat paved surface, with no wind, using the motor and not pedaling. Your mileage may vary, though most people get more than advertised mileage. For the best possible mileage we suggest pedaling anytime the motor is engaged.


How Fast Can I Go?

All Hilltopper electric bikes and kits have a maximum speed of 20 mph. This keeps them street legal and compliant with state laws and city ordinances in the US.

For choosing a power system, here's what to keep in mind: The 36v, 350 watt kits (Horizon) can go 20 mph with minimal pedaling. This is great for steeper hills, faster commutes & carrying bigger loads.

The 36v, 250 watt kits (Sprinter) can go 15 mph with minimal pedaling on flat ground, but they perform best as a boost to your pedaling with pedaling required on hills. Perfect if you are looking for an added boost to your ride at an affordable price. Cuts your commute time by 25%, gives a boost up hills & puts a smile on your face.


How Do I Charge My Hilltopper?

For all of our electric bikes and conversion kits we've made sure charging is easy as can be. Just a few simple steps:

• Grab the charger supplied with your Hill Topper and plug it into the wall. For the best possible performance we recommend plugging directly into the wall, avoiding the use of extension cords and power strips whenever possible.
• Once the green light on the charger comes on, go ahead and plug the barrel end into the battery.
• When the charger is connected to the battery the light should turn from green to red to indicate that it is filling up the battery.
As soon as the battery is full the light will turn back to green so you know it's done.

That's it! Follow these steps and you can rest assured you'll be ready to roll!


When Should I Charge My Hilltopper?

You can charge your Hilltopper whenever you like! All of our batteries are smart batteries with no memory affect, so there is no need to drain it fully before recharging like you would with older battery types like NiCad or others.

Generally we suggest simply charging it after every ride, or at the end of the day if you are a regular commuter. That way you always know your battery is ready to go when you are.

If you are putting the bike away for the winter or just know you won't use it for some time, we suggest charging it fully first and storing it in doors. For the absolute best life of your battery we would also suggest plugging it back into the charger every month or so to keep it topped up. Before you ask, no, unfortunately we cannot suggest simply leaving the battery plugged into the charger long term.


Need a Bigger or Smaller Tire? No Problem!

All HillTopper kits come complete with a tire already installed so you can get going quickly. That said, our awesome tires might not be the best fit for you bike or your style. No problem, swapping out the tire to meet your needs or match your other wheel is super easy. Our rims can fit a wide variety of tires, everything from skinny road tires (25 mm minimum) to big 2.2" mountain tires.

For instructions check out the following video:


When You Buy a Bike Hilltopper Gives a Bike To a Child In Need

When you buy a bicycle from Hilltopper we donate a bike in your name to a child in need here in Seattle. Your gift of a bicycle helps young people develop self-reliance, leadership, and life skills at, a community driven non-profit here in Seattle. Low-income children at Bike Works receive their donated kids bike at a family bike swap. Teens receive their donated bike as part of the Earn-a-bike program, where they learn how to build and repair bicycles, put their new skills to good use by volunteering to help others fix their bike, and earn a new bike at the end.


Free Shipping / Delivery Time

Free Shipping on All Orders!

You read that right, get free shipping* on all orders! (*Applies only to orders in the contiguous 48 states.)


Shipping & Delivery Time

Hilltopper kits are hand built in batches by our team of craftspeople, and each kit is rigorously tested before leaving our shop.

For full kit purchases and any purchases containing a battery, please expect 7 - 14 business days for our team to build, test, and ship your kit.

For smaller items, such as accessories or components, please expect 1 - 3 business days for our team to process and ship your items.

For more detailed information, please check the product page of each kit for the latest updates regarding availability or email us at


Warranty & Returns

Warranty & Returns

For all returns or warranty claims contact

• 30-day money back guarantee. Returns of undamaged conversion kits may be issued full refunds less a $50.00 restocking fee. Returns of undamaged complete bikes may be issued full refunds less a $100.00 restocking fee.
• Warranty only applies to original owner (non-transferable).
• 1-year standard warranty on all batteries. 2-year standard warranty on all other components.
• Warranties can be used for an exchange of a component only once.
• Customer pays return shipping on warrantied component inspections. Please note some battery returns may require special documentation and packaging, and these instances will encounter extra fees. This is in order to correctly comply with lithium battery shipping regulations. For all return shipping we recommend using a local shipping service like FedEx office or the UPS Store.
• If you have a quality issue with a product please contact support to help diagnose the problem. If a product does not meet our high quality standards, then we will issue you a replacement component or fix the original at no additional cost. Replacement components will only be sent after we have received your returned component and finished an inspection to determine the cause of any problems. Hill Topper Bikes is not responsible for return shipping.
• Do-It-Yourself modifications, normal wear, and damage due to gross negligence or abuse are not covered by the warranty.