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Check out below for our most Frequently Asked Questions.
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Frequently Asked Questions
Will a Hilltopper Kit Fit My Bike?
Hilltopper Kits Fit Most Bikes
Most adult bicycles and adult tricycles can work with a Hilltopper conversion kit. Our kits are designed to fit a wide variety of bikes, and our wheels work with both rim brakes and disc brakes.
There are a few important things to check before ordering:
- Wheel size
- Fork dropout type
- Front hub/fork spacing
- Pedal Assist Sensor (PAS) compatibility, if you plan to use PAS
Use the sections below to check each one. If you're still unsure after measuring your bike, our customer service team can help.
What wheel size do I need?
Your Hilltopper wheel needs to match the wheel size of your existing bike.
We currently offer:
- 700c / 28" / 29" — these all use the same 622 mm rim diameter
- 650b / 27.5"
- 26"
- 24"
- 20"
We do not currently offer a 27" wheel, and custom wheel sizes are not available.
The easiest way to find your current wheel size is to look for the size printed on the sidewall of your existing tire.
NOTE: Do NOT attempt to measure your wheel. You absolutely must use the label printed on your tire or you will order the wrong size.
What type of fork dropout does my bike need?
The dropout is the part at the bottom of your front fork where the wheel axle sits.
Hilltopper conversion kits require a traditional open or slotted dropout — the familiar U-shaped opening found on most bicycles.
Our conversion-kit axles are 10 mm wide.
If your bike has a closed dropout designed for a thru-axle, our conversion kits are not compatible with that fork.
How do I check my front hub/fork spacing?
Our conversion-kit hubs use 100 mm (about 3.9") of axle spacing, which is standard on many bicycles.
To check yours, measure the distance between the inside faces of your fork dropouts where the front hub sits. You're looking for approximately 100 mm / 3.9".
There's one additional measurement that's important because the Hilltopper motor is larger than a traditional bicycle hub. Ideally, the fork should maintain approximately 100 mm / 4" of spacing for at least 3" above the dropout.
If your measurements are close but you're not sure, contact us before ordering and we'll help you determine whether your bike is a good fit.
Will the Pedal Assist Sensor (PAS) fit my bike?
PAS is an optional feature on our 36V Horizon and 48V Summit kits.
The PAS sensor mounts near the bike's bottom bracket and uses a magnetic wheel to detect when you're pedaling. Because bottom brackets and crank setups vary, compatibility depends on the design of your bike.
For detailed compatibility information, see our PAS Compatibility & Installation Guide and installation video.
Do Hilltopper wheels work with disc brakes?
Yes! All Hilltopper wheels are compatible with disc brakes and rim brakes.
Our wheels use standard spacing and a 6-bolt rotor attachment for disc brakes.
If you're installing a disc brake rotor on your new Hilltopper wheel, check out our installation video:
Can I use a different tire on my Hilltopper wheel?
Absolutely. Every Hilltopper kit comes with a tire already installed, but you can swap it for another tire if you'd like a different size, tread, or riding style.
Our rims accommodate a wide range of tires, from approximately 25 mm road tires up to 2.2" mountain-bike tires.
How Do I Know Which Hilltopper Kit Is Right for Me?
The right Hilltopper kit depends on how much power you need, how far you want to ride, and how much you want to pedal.
Sprinter — 36V, 250W
The Sprinter is a good option for shorter rides and riders who are comfortable doing some pedaling, especially on hills. It can reach about 16 mph on flat ground with minimal pedaling.
Horizon — 36V, 350W
The Horizon offers more power and range than the Sprinter. It can reach about 20 mph with minimal pedaling and has an estimated range of 25–50+ miles under ideal conditions. An optional pedal-assist system (PAS) is available.
Summit — 48V, 500W
The Summit is designed for riders who want more power for heavier loads or steeper hills. It can reach about 20 mph and has an estimated range of 25–50+ miles under ideal conditions. An optional PAS system is available.
Quick comparison
- Sprinter: 250W · 16 mph · 10–20+ miles · Shorter rides and more pedaling.
- Horizon: 350W · 20 mph · 25–50+ miles · More range and less pedaling.
- Summit: 500W · 20 mph · 25–50+ miles · Heavier loads and steeper hills.
*Speed and range vary depending on rider weight, bike weight, terrain, wind, and how much you pedal. The range estimates above are based on a 170 lb rider, 30 lb bike, flat paved surface, no wind, and motor-only riding.
If you're still unsure which kit is right for you, our technical support team can help you choose based on your bike and riding needs.
How much power do I need?
It depends mostly on how fast you want to ride, how steep your hills are, and how much weight you're carrying.
36V 250W Sprinter
The Sprinter can reach about 16 mph with minimal pedaling on flat ground. It's designed primarily as a boost to your own pedaling and is a good choice if you want an affordable assist for everyday riding and moderate terrain.
36V 350W Horizon
The Horizon can reach up to 20 mph with minimal pedaling and provides more power for hills, faster commuting, and heavier loads.
48V 500W Summit
The Summit can reach up to 20 mph with minimal pedaling and provides the most power of the three systems. It's designed for riders who want strong acceleration, steeper hill-climbing ability, or more assistance while carrying heavier loads.
If you're deciding between systems, think about your typical terrain and how much help you want from the motor.
How fast can a Hilltopper go?
Hilltopper electric bikes and conversion kits are limited to a maximum assisted speed of 20 mph.
Actual speed depends on the system, rider weight, terrain, wind, battery charge, and how much you're pedaling.
The 250W Sprinter is designed for approximately 16 mph with minimal pedaling on flat ground, while the 350W Horizon and 500W Summit can reach up to 20 mph with minimal pedaling.
How far can I go on a charge?
Range depends on many factors, including rider weight, bike weight, terrain, wind, tire pressure, temperature, and how much you pedal.
As a general guide, the current published ranges are:
- 36V Sprinter: 10–20+ miles
- 36V Universal Replacement Battery: 20–25+ miles
- 36V Horizon: 25–50+ miles
- 48V Summit: 25–50+ miles
These estimates are based on a 170 lb rider, a 30 lb bike, flat paved terrain, no wind, and using the motor without pedaling. Your actual range may be higher or lower.
For the best range, pedal whenever the motor is running.
What is the variable-speed throttle, and will it fit my handlebars?
The variable-speed throttle lets you control the amount of power going to the motor — similar to a gas pedal.
It can be installed on either side of your handlebars and positioned to suit your riding style. We generally recommend installing it on the left, between the handlebar grip and the brake/shifter controls.
The throttle is designed for handlebars with a 22.2 mm grip diameter, which is common on flat and riser handlebars.
If you have road-bike drop bars or another unusual handlebar shape, the standard throttle may not fit directly. An adapter or handlebar accessory can provide a workaround.
How do I install my Hilltopper kit?
Installation is designed to be straightforward and can generally be completed with basic tools.
The exact steps depend on your kit. Choose your model below for the appropriate installation guide.
36V Sprinter Installation
The Sprinter installation involves:
- Remove your bike's original front wheel.
- Install the Hilltopper electric wheel, making sure all axle hardware is correctly positioned.
- Install the battery mount on your bike's water-bottle mounts or rear carrier, then secure the battery.
- Install the throttle on the handlebars.
- Connect the battery to the motor using the thick black cable. Align the arrows on the connectors.
- Connect the battery to the throttle using the thin cable with yellow connectors.
Download the Sprinter installation guide
36V Horizon Installation
The Horizon installation includes the same basic wheel, battery, and throttle setup, plus the optional Pedal Assist Sensor.
Download the Horizon installation guide
Watch the Horizon installation video
48V Summit Installation
The Summit installation includes the wheel, battery, throttle, LCD display, and optional Pedal Assist Sensor.
How do I charge my Hilltopper?
Charging is simple:
- Plug the supplied charger into a wall outlet. For best performance, plug it directly into the wall rather than using an extension cord or power strip.
- When the charger light turns green, connect the charger to the battery.
- The light should turn red while the battery is charging.
- When the battery is fully charged, the light will turn green again.
That's it — you're ready to ride!
When should I charge my battery?
You can recharge your Hilltopper whenever you like. Our batteries do not need to be fully drained before charging.
For regular riding, we recommend charging after each ride or at the end of the day so your battery is ready for your next trip.
If you're storing your bike for an extended period, charge the battery fully, disconnect it from the charger, and store it indoors in a temperature-controlled space when possible.
For long-term storage, we also recommend checking the battery about once a month and topping it up as needed.
Do not leave the battery connected to the charger indefinitely.
How should I store my battery?
For long-term storage:
- Remove the battery from the bike when practical.
- Charge it fully.
- Disconnect it from the charger.
- Store it indoors in a temperature-controlled location.
If you live somewhere with very cold winters, bringing the battery indoors for the season is a good idea.
How do I replace my battery?
If your battery needs replacing, you can order a replacement online or contact us at contact@hilltopperbikes.com for assistance.
If you're not sure which replacement battery you need, contact us before ordering.
Is my kit compatible with the 36V Universal Replacement Battery (URB)?
If you're wondering whether your existing Hilltopper kit works with our Universal Replacement Battery, check our compatibility guide:
Hilltopper URB Compatibility Cheat Sheet
If you're still unsure, contact contact@hilltopperbikes.com and we'll help you determine compatibility.
What should I do if my charger, throttle, or cables are damaged or missing?
No problem. Chargers, throttles, cables, and other small components can be replaced.
You can order replacement parts online by visiting the Batteries & Parts page or contact contact@hilltopperbikes.com for help identifying what you need.
What if my Hilltopper wheel is bent?
If your wheel has a small wobble, a local bike shop can often straighten it by truing the wheel.
If the wheel is significantly bent, truing may not be enough. A bike shop can inspect it and let you know whether the rim can be repaired or should be replaced.
If you need a replacement rim, you can purchase one through a bike shop or contact contact@hilltopperbikes.com for an identical replacement. Your bike shop can then lace the new rim to your existing Hilltopper hub/motor.
What if I'm missing hardware or another small part?
If something is missing from your order or you need a small replacement part, contact our customer service team at contact@hilltopperbikes.com.
We'll help you identify what you need and get you back on the road.
In a pinch? You can always check your local hardware store for standard nuts and washers. Sometimes this is the fastest way to get the simplest parts.
What is the Discover C9?
The Discover C9 is Hilltopper's gravel e-bike. It combines the riding characteristics of a road bike with features designed for a wider variety of surfaces, including gravel and rough city streets.
The Discover uses 650b wheels with wider tires, a more upright riding position, and a fork designed for rougher roads. It also includes mounting points for front and rear racks.
The Discover is designed for on-road riding and is not a mountain bike. It is not intended for jumps or large drops.
How long does shipping take?
For most orders, please allow 1–5 business days for our team to process and ship your order.
For the most current availability information, check the product page for the kit or bike you're ordering.
If you have a question about a specific order, contact contact@hilltopperbikes.com or click the WhatsApp icon for live chat.
What payment methods do you accept?
We accept major credit and debit cards, including:
- Visa
- Mastercard
- American Express
- Discover
- Diners Club
Hilltopper does not store your credit card information.
You may also use common online payment methods, including:
- Shop Pay
- Apple Pay
- Google Pay
- PayPal Wallet
If you'd prefer to pay by check, phone orders are also available. Please call +1 702-510-9027 for assistance. Orders paid by check ship after the check has been received.
What is your Warranty & Return Policy?
For all warranty claims or returns, contact contact@hilltopperbikes.com before sending anything back.
Returns
Hilltopper offers a 30-day money-back guarantee.
For undamaged products returned within the applicable period:
- Conversion kit returns may receive a full refund less a $50 restocking fee.
- Complete electric bike returns may receive a full refund less a $100 restocking fee.
For eligible returns within the 48 contiguous states, Hilltopper will reimburse basic UPS or FedEx Ground return shipping when the return is initiated with us and sent back within 30 days of receiving the item. Please contact us before shipping your return.
Warranty
Hilltopper products include a 1-year warranty on all components.
The warranty:
- Applies only to the original owner and is not transferable.
- May be used for a component exchange once.
- Does not cover DIY modifications, normal wear, gross negligence, or abuse.
- Requires the affected component to be returned for inspection when requested.
If you believe you have a quality issue, contact our support team first so we can help diagnose the problem. If the product is determined to have a covered quality issue, Hilltopper will repair the original component or provide a replacement component at no additional cost.
Replacement components are sent after the returned component has been received and inspected to determine the cause of the issue.
The customer is responsible for return shipping for warranty inspections. Some battery returns may require special documentation or packaging and may involve additional fees because of lithium-battery shipping regulations.
To initiate a return, contact contact@hilltopperbikes.com.
If instructed to return an item, include a note with:
- Your name
- Email address
- Phone number
- Order number
- Reason for the return
Return address:
Hilltopper Bikes Technical Support Team
Attn: (Order Number)
4786 1st Ave S, Suite 103
Seattle, WA 98134
USA
Why are Hilltopper bikes and kits priced so affordably?
We sell directly to customers rather than through dealers, distributors, or traditional retail stores.
That direct-to-customer model allows us to keep costs lower and make electric bikes and conversion kits more accessible.
We design our kits and bike wheels here in Seattle and sell directly to riders.
Does Hilltopper donate bikes to children in need?
Yes. When you purchase a bicycle from Hilltopper, we donate a bike in your name to a child in need in Seattle through Bike Works.
Bike Works provides bicycles and programs designed to help young people develop practical skills, confidence, and independence.
Do you offer technical support?
Yes. Hilltopper provides lifetime technical support.
If you have a question about installation, compatibility, replacement parts, or troubleshooting, contact our team at contact@hilltopperbikes.com or use our Contact form.