E Bike Serial Number Location Guide By Brand

Your e-bike’s serial number is the key that unlocks warranty service, insurance claims, theft recovery, and correct replacement parts. Unlike a standard bicycle, an e-bike’s frame number can be tucked behind a battery mount, under a motor housing, or stamped into a folding hinge—locations dictated by where the manufacturer routed the wiring and drivetrain components.

Before you start hunting, gather a few tools: a bright flashlight (hold it at a low angle to catch shallow stampings), a clean rag to wipe away grime, and a phone camera to document the number once you find it. For stickers that have faded or partially peeled, a magnifying glass helps. Budget 5–10 minutes for your first search, especially if you need to remove a chain guard or battery.

The Three Standard Locations to Check First

Most e-bike manufacturers use one of three frame positions. Start with these before diving into brand-specific details:

• Bottom bracket – The cylindrical shell where the crank arms attach to the frame. This is the most universal location across all bike brands, e-bike or not. On e-bikes, the chainring and motor housing can partially obscure it.
• Head tube – The vertical front tube where the fork meets the frame. Check the side or front face, often near the brand decal. This spot is common on mid-drive bikes where the motor occupies the bottom bracket area.
• Rear dropout – The flat metal tab on the rear frame where the wheel axle sits. Hub-drive e-bikes often stamp the number here to keep it clear of the motor and wiring.

If you find a number but can’t read it fully, try the pencil-rubbing technique: lay a piece of paper over the stamping and rub gently with a pencil to reveal the characters. This works well on deep mechanical stamps but not on faded stickers.

Brand-by-Brand Serial Number Locations

Rad Power Bikes

Rad Power stamps the serial number on the bottom bracket, underneath the frame where the pedals connect. On RadRover and RadCity models, a plastic chain guard often hides the number—you’ll need to remove two Phillips-head screws to read the full 14-character code. On newer RadExpand models, the serial is duplicated on a sticker inside the battery compartment door.

Rad serials typically start with two letters that identify the model line (e.g., “RR” for RadRover, “RC” for RadCity), followed by numbers. The letter code matters: if you’re ordering a replacement battery or controller, the model prefix confirms compatibility with your specific generation. A 2021 RadRover and a 2023 RadRover share the same name but may use different connectors, so matching the prefix prevents ordering a battery that physically fits but won’t communicate with your display.

If you remove the chain guard and find only a partial stamping, check the battery compartment door before assuming the frame number is worn. Rad duplicates the serial there on most models produced after 2020. If both locations are illegible, the battery itself carries a sticker with the frame serial on its underside—remove the battery and look for a white label near the mounting rails.

Trek (including Electra)

Trek e-bikes (Allant+, Verve+, Powerfly) engrave the serial number on the bottom bracket shell rather than using a sticker. The engraving is deep enough to survive paint touch-ups, but dirt and chain grease can fill the grooves—wipe the area with a clean rag before trying to read it.

On Electra Townie Go! models, the serial sits on the head tube, behind the front reflector bracket. You’ll need to loosen the reflector bracket (one hex bolt) to see the full number. Trek serials are 15 characters and include a letter that identifies the model year—”T” indicates 2023, “U” indicates 2024. This letter is critical when ordering frame-specific accessories like racks or fenders, as mounting points changed between generations.

If you find a serial that starts with “WT” on a Trek e-bike, you’re likely looking at a frame made for the Electra sub-brand—these use a different numbering scheme. Don’t panic if the format doesn’t match the standard 15-character Trek pattern; the full string is still valid for warranty claims.

Specialized

Specialized e-bikes (Turbo Vado, Turbo Levo, Como) use a serial number sticker on the bottom bracket, covered by a clear protective film. On mid-drive models, the motor housing partially obscures the sticker—tilt the bike sideways to get a direct view. On Turbo models with a removable battery, check the inside of the battery slot on the downtube; Specialized duplicates the serial there.

The battery slot location is the better option for long-term legibility because it stays protected from road spray and UV exposure. The bottom bracket sticker, by contrast, sits directly in the path of front-wheel spray and can peel within 2–3 years of regular commuting.

Specialized serials are 12–14 characters and don’t follow a public model-year code—unlike Trek, you can’t decode the year from the string. If you need to verify the model year, you’ll need to contact a Specialized dealer with the serial in hand.

If the bottom bracket sticker is gone and the battery slot is empty, check the motor casing itself. Specialized mid-drive motors (Brose and Specialized 2.0/2.2) have a separate serial stamped near the cable exit. This motor serial is what Specialized service centers need for firmware updates and warranty repairs—the frame serial alone won’t suffice for motor claims.

Giant/Liv

Giant e-bikes (Explore E+, FastRoad E+, Trance E+) stamp the serial number on the bottom bracket and also place a sticker inside the battery mount cavity. The battery cavity sticker is easier to read because it’s protected from road grime and never gets covered by the chainring.

Giant serials are 12–14 characters and start with two letters indicating the factory code. The bottom bracket stamp is deep mechanical engraving, so it survives even if the battery cavity sticker peels off. Liv models (like the Amiti E+) follow the same pattern.

If the battery cavity sticker is present but the bottom bracket stamp is unreadable, trust the sticker—Giant’s cavity stickers are printed on durable polyester and typically outlast the frame’s paint. However, if the sticker and stamp show different numbers, stop and contact Giant support before proceeding with any registration or warranty claim. Mismatched numbers can indicate a frame replacement that wasn’t properly documented, and filing a claim with the wrong serial will delay your service.

BAFANG Conversion Kits

If you have a custom build using a BAFANG Mid Drive Kit, you have two separate serial numbers to track. The motor itself has a serial stamped on the motor housing, near the cable exit point. The frame’s original bicycle serial remains on the bottom bracket.

BAFANG motor serials are 12 digits and often begin with “M” for mid-drive units. This motor serial is what you need for warranty claims, firmware updates, and ordering replacement controllers or wiring harnesses. BAFANG uses the serial to verify compatibility with specific firmware versions—a controller ordered without the correct serial match may not communicate properly with your motor.

If you’re ordering a replacement BAFANG motor, check whether your existing motor serial starts with “M” or a different prefix. Older BBS01 and BBS02 units use different serial formats than the newer BBS02B and BBSHD models. The prefix determines which mounting bracket and wiring harness you need, so don’t skip this check before purchasing.

If your BAFANG motor serial is scratched, ground off, or otherwise illegible, stop and contact BAFANG support directly. Unlike frame serials, motor serials are required for firmware updates, and attempting to flash firmware without a valid serial can brick the controller. BAFANG support can look up your motor by purchase date and retailer if you have the original order information.

Dahon Folding E-Bikes

Dahon folding e-bikes (like the VYBE D7 or Mariner D8) place the serial number on the steering tube—the part of the frame that inserts into the headset—or on the rear dropout. On the Dahon VYBE D7 Folding Bike, the serial is on the bottom of the frame near the folding hinge. You’ll need to unfold the bike completely and look at the hinge plate from underneath.

Dahon serials are 10–12 characters and include the production date code in the middle digits. The hinge location is unique to folding bikes—traditional frame locations like the bottom bracket may not exist or may be covered by the folding mechanism.

If you find a serial on the hinge plate but it’s partially obscured by the hinge pin, try rotating the folding mechanism slightly to expose the full stamping. If the number remains hidden, check the steering tube by removing the front reflector bracket—Dahon often duplicates the serial there on newer models.

Aventon

Aventon e-bikes (Level, Pace, Sinch) stamp the serial number on the bottom bracket and also place a sticker on the seat tube—the vertical tube that holds the seatpost. The seat tube sticker is more visible but can peel after exposure to rain. On the Aventon Sinch folding model, check the rear dropout on the non-drive side; the number is engraved into the frame.

Aventon serials are 12–14 characters, and the first two digits indicate the production year. If you’re buying a used Aventon, check that the seat tube sticker matches the bottom bracket stamp—mismatched numbers can indicate a stolen bike with a swapped frame.

If you find a seat tube sticker but no bottom bracket stamp, the bike may be a pre-2020 model that used a sticker-only serial. Aventon switched to dual-location serials in 2020, so a missing bottom bracket stamp on an older model isn’t necessarily a red flag. However, if the seat tube sticker looks recently replaced or shows signs of tampering (bubbles, misalignment, cut edges), treat the bike with suspicion and run the serial through BikeIndex.org.

Juiced Bikes

Juiced models (Scorpion, RipCurrent, HyperScrambler) place the serial number on the head tube on the right side, just above the front fork. On the Scorpion X, the number is also stamped on the bottom bracket under the battery tray.

Juiced serials are 13 characters and include a two-letter prefix for the model line. The head tube location is convenient because it’s visible without removing any components, but it’s also exposed to direct sunlight—the sticker can fade within 2–3 years of outdoor storage.

If the head tube sticker has faded beyond recognition, remove the battery and check the bottom bracket stamp. Juiced uses a mechanical stamp there, which survives UV exposure much better than the sticker. If both locations are illegible, check the controller box (usually inside the frame near the bottom bracket)—it often carries a matching serial.

When the Serial Number Is Missing or Illegible

If the serial number has been ground off—a common sign of a stolen bike—or if the sticker has faded beyond recognition, you still have options:

• Check the motor controller – On hub-drive e-bikes, the controller box (usually inside the frame or under the battery) often has a separate serial that matches the frame. You may need to remove the battery and look into the downtube opening with a flashlight.
• Contact the retailer – If you bought from a shop, their sales records include the serial. Many shops keep a copy of the bike’s serial in the service log. Even if you bought online, the original order confirmation email may list the serial.
• Use the battery serial – Some brands (like Rad and Aventon) print the frame serial on the battery casing as a backup. Remove the battery and look for a sticker on the underside. The battery serial itself is different from the frame serial, but the sticker often lists both.

A serial number that appears “sandblasted” or uniformly scratched off is almost always deliberate tampering, not normal wear. Normal wear produces partial legibility—you can still make out some characters. If the entire serial area is uniformly smooth, the frame was likely ground down to hide theft. In this case, do not attempt to re-stamp or alter the frame; contact local law enforcement and provide the bike’s make, model, and purchase documentation.

How to Record and Protect the Serial Number

Once you find the serial, write it down in two places: a digital note (phone or email to yourself) and a physical card kept with your owner’s manual. Take a clear photo with your phone, ensuring the entire number is in focus.

For extra security, consider engraving the serial onto a small metal tag and attaching it to the seatpost clamp—this creates a visible deterrent if the frame number is tampered with. If you use a Rightcar Solutions Motorcycle License Plate Frame on a cargo e-bike with a rear plate mount, you can also record the serial on a small sticker placed behind the plate for discreet backup.

Another practical method: use a permanent marker to write the serial on the inside of the battery compartment cover. This spot is protected from weather and won’t be visible to thieves, but you’ll see it every time you swap batteries.

If you’ve spent 20 minutes searching and still can’t find the serial, stop and contact the manufacturer’s support line with your purchase date and retailer. Most brands can look up the serial from their sales records. Do not attempt to disassemble the motor housing or bottom bracket to find a hidden serial—this can void your warranty and damage components that require specialized tools to reseat.

Frequently Asked Questions

Can I use the serial number to check if an e-bike is stolen?

Yes. Run the serial through BikeIndex.org or the local police department’s stolen bike database. Most manufacturers also keep a theft registry for warranty claims.

What if the serial number has letters and numbers? Do I include the letters?

Always include every character. The letters indicate the model year, factory, or production batch, and warranty claims require the full string.

Does the serial number change if I replace the motor?

No. The frame serial remains the same. The motor has its own separate serial number. Keep both recorded separately for warranty and insurance purposes.

Where is the serial on a folding e-bike that doesn’t have a bottom bracket?

On folding bikes like the Dahon VYBE D7, check the hinge mechanism plate, the steering tube, or the rear dropout. The frame’s folding joint often carries the stamping.

How long does it take to find the serial number on a typical e-bike?

Usually 2–5 minutes if you know where to look. Removing a chain guard or battery adds another minute.

What should I do if the serial number is partially worn but I can read some characters?

Record what you can read and contact the manufacturer. Many brands can narrow down the full serial using the partial string plus your purchase date and model name. Don’t guess at missing characters—an incorrect full serial can cause warranty claim delays.