E-Bike Serial Number Location Guide: Where to Find It on Every Major Brand

If you need your e-bike’s serial number for a warranty claim, police report, or insurance registration, the three most common places to look are: on the bottom bracket (where the pedals attach to the frame), on the head tube (near the front fork), or on the rear dropout (where the rear wheel mounts). Serial numbers are typically 7–17 digits and may include letters. This guide walks you through exactly where to find them on every major e-bike brand, how to decode the number, and what to do if it’s hidden or worn off.

What You’ll Need Before You Start

• A bright flashlight (phone light works)
• A clean rag or paper towel
• A 4mm hex key (to remove plastic guards or battery covers on some models)
• A pencil and paper (for rubbing worn numbers)
• Your phone for photos and lookup

Having these ready will speed up the search and prevent you from missing a faint number.

Why Your E-Bike Serial Number Matters

Your serial number is the single key that ties you to the bike’s history. Without it:

• Warranty claims are often denied – manufacturers use the serial to verify the model year and purchase date.
• Police reports for stolen bikes rely on the serial to enter the bike into national databases (e.g., Bike Index, 529 Garage).
• Insurance policies (homeowner’s, renter’s, or dedicated bike insurance) require the serial to list the bike as a covered item.
• Theft recovery is nearly impossible without a recorded serial – shops and pawn shops check numbers against stolen-bike listings.

Where to Look First: The Three Common Spots

Check these locations in order. Dirt and grease often hide the number, so clean the area before giving up.

Location	Typical Appearance	Best Way to See It
Bottom bracket (underside of frame where cranks attach)	Stamped or etched into metal, often horizontal	Flip bike upside-down or lean against a wall; wipe dirt away
Head tube (front of frame, near the fork crown)	Sticker or laser-engraved, sometimes on the left or right side	Turn handlebars to full lock; use a bright light
Rear dropout (flat tab on the frame that holds the rear axle)	Stamped or engraved, small digits	Remove rear wheel if needed for clear view; check both sides

A typical bottom-bracket serial appears as a line of numbers and letters milled into the cylindrical metal surface between the crank arms. Dirt often collects here, so a rag and flashlight can help. If you find a number on the bottom bracket but it’s too worn to read clearly, try the pencil-rubbing method. Lay a piece of paper over the area and rub gently with the side of a pencil lead. If that still doesn’t produce a legible result, check if your brand prints a duplicate serial on a sticker under the battery tray or inside the head tube cover. Use that duplicate as your primary record.

Brand-by-Brand Serial Number Locations

Each major e-bike brand places the serial in a specific – and sometimes unusual – spot. Use the list below for direct guidance.

Trek / Bontrager

• Location: Bottom bracket, on the underside of the frame, oriented horizontally.
• Also check: Some 2023+ models have an additional sticker on the down tube (near the water bottle cage) that lists the serial alongside the model name.
• Format: 14-digit alphanumeric code, often starting with “WTU” or “E” for e-bike models.
• Tip: If the bottom bracket is covered by a plastic guard (common on the Allant+ and Verve+ lines), remove the guard with a 4mm hex key.

Specialized (Turbo series)

• Location: Head tube, on the left side (when sitting on the bike), laser-etched into the metal.
• Also check: On older models (pre‑2022), the serial is also repeated on a small sticker under the battery mount.
• Format: 16-digit code beginning with “WSBC” or “WUD.”
• Hidden note: Turbo e‑bikes with a fully integrated battery/tube design (like the Turbo Como) hide the serial under a plastic cover on the head tube. Pop the cover off with a plastic pry tool.

Giant / Liv

• Location: Bottom bracket, stamped into the flat area just behind the crank arm on the non‑drive side.
• Also check: On models with a removable battery (e.g., Explore E+), a matching serial appears on the battery casing itself.
• Format: 12-digit number starting with “GF” or “GL.”
• Practical tip: Giant uses a very light stamp – use a rubbing technique (pencil and paper) to reveal worn digits.

Rad Power Bikes

• Location: Rear dropout, on the right side (where the rear axle nut sits). The serial is stamped into the flat metal tab.
• Also check: Under the battery – lift the battery out and look at the top of the frame’s battery tray. Some RadCity and RadRover models also show the serial there.
• Format: 10–14 characters, often starting with “RP” or “RAD.”
• Caution: Rad bikes that have been repainted or heavily used may lose the dropout stamp. If so, check the battery tray.

Bosch‑Powered E‑Bikes (generic – applies to brands like Cannondale, Cube, KTM)

• Location: Bottom bracket, on the motor housing itself (not the frame). The Bosch motor serial is printed on a silver sticker wrapped around the motor.
• Also check: The drive unit’s side casing often has a smaller barcode with the same number.
• Format: 16 digits, usually starting with “B” or “0B.”
• Why it matters: Bosch serial numbers are used for motor‑specific warranty and firmware updates – keep a photo of this sticker.

Yamaha‑Powered E‑Bikes (e.g., Haibike, Lapierre, some Giant models)

• Location: Head tube, on the right side, laser‑engraved.
• Also check: The drive unit (rear hub or mid‑drive) has its own serial – the frame serial is the one you need for registration.
• Format: 13‑digit code starting with “Y” followed by numbers.

Other Notable Brands

• Aventon: Bottom bracket, stamped into the metal. On models like the Aventure.2, look under the battery – there’s a sticker with the serial next to the charge port.
• Riese & Müller: Under the battery mount on the downtube, laser‑etched into the carbon or aluminum. Also on the main frame sticker (usually on the down tube).
• VanMoof: Hidden under the rear fender. You must remove the rear wheel and look at the inside of the right dropout. Very small – use a magnifying glass.
• Cannondale (with Bosch motor): Follow the Bosch guidance above. Stand-alone Cannondale e‑bikes (non‑Bosch) use the bottom bracket.

Decoding Your E-Bike Serial Number

Most serial numbers contain information about the model year and sometimes the plant. Here’s how to start decoding:

• Check the first two digits – many brands (Trek, Giant, Specialized) use the year as the first two numbers. For example, a serial starting with “23” likely means 2023 model year.
• Look for a letter in position 3 or 4 – on Bosch motors, that letter often indicates the motor generation.
• Search the brand’s website – most have an online serial‑number decoder or lookup tool specifically for warranty and registration.
• Use a third‑party decoder – sites like bikeindex.org can sometimes identify the brand and model from the serial pattern, but they won’t decode year reliably.

Caution: Serial number formats change across years and regions. If the month/year codes don’t match what you expect, contact the manufacturer’s customer service with a photo of the serial.

Step-by-Step Serial Number Lookup

Follow these steps to record and verify your e-bike serial.

1. Locate the serial using the brand guide above. Write it down and take a clear photo with your phone.
2. Clean and reveal – if the number is faint, use the pencil-rubbing method. If it’s under a sticker, peel back gently.
3. Check the brand’s official lookup page – most major brands have a “serial number lookup” or “warranty registration” section on their site. Enter the number to confirm model year, recall status, and any open service bulletins.
4. Register the bike with a recovery network – go to BikeIndex.org or 529 Garage. Enter the serial, your contact info, and photos. This makes it infinitely easier to get the bike back if stolen.
5. Verify the number works – enter the serial into the look-up tool. If the lookup returns the correct bike model and year, you have the right number. If it returns nothing or a mismatch, double-check the digits and revisit the location.

Common Issues and What to Do Next

Serial not found in any of the three common spots? Check under the battery tray, inside the motor cover, or behind a removable plastic panel (e.g., VanMoof under the rear fender). Some brands also stamp the serial inside the chainstay or seatstay near the bottom bracket.

Serial is too worn to read? Try the pencil-rubbing method first. If the metal is too smooth or the engraving is too shallow, contact the original seller with proof of purchase. They may be able to retrieve the serial from their records.

Stop and escalate: If the serial has clearly been ground off, scratched out, or appears tampered with, do not attempt any further DIY steps. This strongly indicates the bike is stolen. Report the situation to local police with the bike’s make, model, and any other identifiers you have. Never buy a used e-bike without a legible serial.

Frequently Asked Questions

Where is the serial number if I can’t see it on the bottom bracket or head tube?

Some brands hide it under the battery, inside the motor cover, or behind a removable plastic panel (e.g., VanMoof under the rear fender). Check the battery tray first, then look at the inside of chainstays or seat stays.

Can I look up an e-bike serial number by brand without the actual bike?

Not reliably – the serial itself is the only identifier. If you have only a photo of the serial, many brand lookup tools will accept it. If the number is illegible, contact the original seller with proof of purchase.

Do e-bikes have VINs like cars?

No – e-bikes use serial numbers, not VINs. Some states (e.g., California) require a frame number (essentially the serial) for registration, but there’s no standard 17‑digit VIN system for bikes.

My e-bike battery has a different serial number – which one do I use?

Always use the frame serial for ownership and theft reports. The battery serial is for battery‑only warranty claims. Write down both separately.

What if the serial has been ground off or scratched out?

That’s a strong red flag that the bike is stolen. Do not purchase a used e‑bike without a legible serial. If you already own it, report the situation to local police – they may be able to trace hidden markings left by the manufacturer.

Explore This Topic

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• Back to E-Bike Resources

Related guides in this cluster:
– E-Bike Warranty Comparison: Which Brands Offer the Best Coverage?
– E-Bike Error Code Reference: Complete Lookup Table for All Major Brands
– E-Bike Speed Unlock Guide: How to Remove Speed Limiters by Brand & Model
– E-Bike Battery Compatibility Guide: Replacement Options & Cross-Brand Alternatives