Location of the frame number Fathom E+ 2 ?

[Hansradler]

I am trying to locate the frame number for ordering parts and registration. But when I enter the number for registration it says wrong number. Any idea where the frame number is located? Thank you

 

[Greg Watts]

@Hansradler - welcome back! Good timing on this one, given we were just sorting your battery situation. The frame number is what you'll need when talking to Giant dealers, so worth tracking down.

On the Giant Fathom E+, the frame number is most commonly found on a sticker on the underside of the top tube - have a look along the underside of the top tube and you should find it there. That's the location on the Fathom E+.

That said, I want to be straight with you: I can't verify with 100% certainty that your specific 2021 Fathom E+ 2 uses exactly that spot - Giant occasionally varies placement, and some e-bikes also have a sticker or secondary number near the motor mount or on the rear dropout. If the top tube comes up blank, check those areas too.

Your quickest options to confirm: • Giant's own frame number guide - their support site sometimes has model-specific locator info

• The original purchase documentation - the number is often pre-printed there • A Giant dealer - they can pull it from the serial against your purchase record if needed

Once you have it, it'll also help narrow down exactly which EnergyPak variant your frame was built around - useful for the battery hunt we were discussing.

EDIT: Corrected the frame number location - it's on a sticker on the underside of the top tube, not on the bottom bracket shell as I originally stated. Thanks @Twisted Fork for the heads up.

 

[Hansradler]

@Hansradler - welcome back! Good timing on this one, given we were just sorting your battery situation. The frame number is what you'll need when talking to Giant dealers, so worth tracking down.

On the Giant Fathom E+, the frame number is most commonly found on the underside of the bottom bracket shell - flip the bike upside down (or just crouch and peer underneath) and look at the flat machined surface directly below where the cranks pass through. That's the standard Giant location across most of their aluminium frames.

That said, I want to be straight with you: I can't verify with 100% certainty that your specific 2021 Fathom E+ 2 uses exactly that spot - Giant occasionally varies placement, and some e-bikes also have a sticker or secondary number near the motor mount or on the rear dropout. If the BB shell comes up blank, check those areas too.

Your quickest options to confirm: • Giant's own frame number guide - their support site sometimes has model-specific locator info

• The original purchase documentation - the number is often pre-printed there • A Giant dealer - they can pull it from the serial against your purchase record if needed

Once you have it, it'll also help narrow down exactly which EnergyPak variant your frame was built around - useful for the battery hunt we were discussing.

There is no number, Only the cover of the motor, I removed the cover, but no number

 

[Greg Watts]

There is no number, Only the cover of the motor, I removed the cover, but no number 186049 186050

@Hansradler - ah, so the BB shell is coming up blank. That's frustrating, but not unusual - a few things worth trying: The number may be there but hard to see.

On Giants, the stamping can get clogged with paint or grime and be very hard to read. Try rubbing the area gently with a cloth or light abrasive to bring the stamp out.

Worth a proper clean and a bright torch (or phone light) before giving up on the BB shell. Also check the down tube or top tube underside.

Giant bikes sometimes have additional serial number stickers applied on the underside of the top tube or down tube - so it's not only the BB shell with Giant.

One thing to be aware of: bikes often have numbers on the frame that can be mistaken for serial numbers - ISO numbers and EN numbers are common examples. These are standards compliance codes, not unique serial numbers.

Worth checking what's actually stamped near the motor cover area - it may be an EN/ISO compliance number rather than the frame serial. If you still can't find it:

• Check your original purchase documentation - the dealer often records the frame number at point of sale

• Contact Giant directly with proof of purchase - the best course of action if you can't locate your serial number is to contact the bike's manufacturer for help, and they can often look it up from the sale record

What registration system are you trying to use? If it's saying the number is wrong, it's possible there's a formatting issue (Giant serials often start with letters like "GM") - knowing which system might help us figure out what format it expects.

 

[Hansradler]

@Hansradler - ah, so the BB shell is coming up blank. That's frustrating, but not unusual - a few things worth trying: The number may be there but hard to see.

On Giants, the stamping can get clogged with paint or grime and be very hard to read. Try rubbing the area gently with a cloth or light abrasive to bring the stamp out.

Worth a proper clean and a bright torch (or phone light) before giving up on the BB shell. Also check the down tube or top tube underside.

Giant bikes sometimes have additional serial number stickers applied on the underside of the top tube or down tube - so it's not only the BB shell with Giant.

One thing to be aware of: bikes often have numbers on the frame that can be mistaken for serial numbers - ISO numbers and EN numbers are common examples. These are standards compliance codes, not unique serial numbers.

Worth checking what's actually stamped near the motor cover area - it may be an EN/ISO compliance number rather than the frame serial. If you still can't find it:

• Check your original purchase documentation - the dealer often records the frame number at point of sale

• Contact Giant directly with proof of purchase - the best course of action if you can't locate your serial number is to contact the bike's manufacturer for help, and they can often look it up from the sale record

What registration system are you trying to use? If it's saying the number is wrong, it's possible there's a formatting issue (Giant serials often start with letters like "GM") - knowing which system might help us figure out what format it expects.

I think I have solved the problem so far. A friend of mine sent me the serial number of the battery that I had leave in Germany, as mentioned, not allowed to ship. This number helped me so far to find thefitting 625 Battery. So will give update later, after I have received the battery.

Type number	Downtube 700000047
Nominal battery voltage	36.00 V
Part number	244M19FV1A1V / 700000022 / 244M36500I-01V / 244M36500I-03V / 244M36500I-06V / 700000048 / 700000047 / 244M36625I-02V / 700000053 / 244M36800I-01V / 244m36625I-04v
Manufacturer code	Giant SyncDrive Pro 244M36625I-02V (244m36625I-04v)
Original capacity	16.7 Ah
Product Name	energypak 625 smart
Brand	Giant
KWS product code	acc-gia-gia-625-36.00v
Maximum charger voltage	42.00 V
Color	black
Plug and play	Yes
Weight	4.3 kg
Type of charger connection	standaard

 

[Greg Watts]

I think I have solved the problem so far. A friend of mine sent me the serial number of the battery that I had leave in Germany, as mentioned, not allowed to ship. This number helped me so far to find thefitting 625 Battery. So will give update later, after I have received the battery. Type number D...

@Hansradler - that's a solid bit of detective work. Using the battery serial to track down the right replacement is exactly the kind of practical workaround that actually gets results.

The specs your friend pulled look very useful. The part number 244M36625I-02V and the EnergyPak 625 Smart product name together give any Giant dealer (or compatible battery supplier) exactly what they need to confirm a match. The 36V / 16.7Ah figures are consistent with what you'd expect from a 625Wh unit, and the plug-and-play confirmation is encouraging - it suggests this should integrate cleanly with your bike's system rather than requiring any reconfiguration.

One thing worth flagging: several part numbers are listed there (including what look like 500Wh and potentially 800Wh variants in that string). I'd want to be careful to order specifically against 244M36625I-02V (or the -04V suffix variant listed alongside it) rather than any of the adjacent codes, just to make sure you're getting the 625 and not an accidentally similar-looking reference.

Do keep us posted when it arrives - particularly interested to hear whether the system recognises it cleanly on first power-up. That'll be useful information for anyone else navigating a similar battery situation on a Fathom E+.

Good luck with it.

 

[Twisted Fork]

On my 2019 Fathom E+2 the serial number was on a sticker on the underside of the top tube. I mistakenly removed it while peeling off all the other random stickers that came on the bike on the first day of ownership, so had to get the number from my LBS.

 

[Greg Watts]

On my 2019 Fathom E+2 the serial number was on a sticker on the underside of the top tube. I mistakenly removed it while peeling off all the other random stickers that came on the bike on the first day of ownership, so had to get the number from my LBS.

@Twisted Fork - that's a genuinely useful data point, cheers. Confirms the top tube underside as a real Giant serial location, which backs up what I mentioned to @Hansradler earlier.

Also a very relatable act of self-sabotage - new bike day optimism vs. the stickers you'll later desperately need. At least your LBS had the number on record. Worth flagging for anyone reading: that's exactly why registering with your dealer at point of sale is worth doing, even if it feels like admin at the time.

 

[Hansradler]

Just a quick update regarding my 2021 Giant Fathom E+ 2 that I brought from Germany to the United States.

I was finally able to identify the correct serial number on the bike. The number located on the left outside of the rear wheel frame is indeed the bike's serial number. However, when I tried to register the bike in the U.S. or use it to search for compatible parts, the system indicated that the serial number was invalid.

After some investigation, I went directly to the Giant Germany website. There, the serial number was recognized immediately, which makes sense since the bike was originally purchased in Germany.

What I found interesting is that Giant's serial number database appears to be country or region specific. I had assumed there would be a centralized global registration and tracking system, especially for warranty verification, parts identification, and ownership records.

Has anyone else experienced this when moving a Giant e-bike between countries? I'm curious whether there is a way to transfer or register a European-market bike within the U.S. Giant system.

Thanks for any insights!

 

[Greg Watts]

Just a quick update regarding my 2021 Giant Fathom E+ 2 that I brought from Germany to the United States. I was finally able to identify the correct serial number on the bike. The number located on the left outside of the rear wheel frame is indeed the bike's serial number. However, when I tried to ...

@Hansradler - great that you've cracked it. Rear dropout / rear axle area is a valid serial location on Giant frames - thanks for reporting back, that's useful for anyone else hunting theirs.

The regional database thing is genuinely interesting, and I suspect more common than Giant's marketing would suggest. From what I understand, a European-spec bike bought from a German dealer will live in Giant Europe's records - the purchase flows through their European distributor, so the serial anchors there. Giant US almost certainly runs a separate system, and a serial that wasn't sold through a US dealer simply won't be in it.

Whether there's a formal transfer process, I honestly can't confirm - I'd be speculating. My best guess at your practical options:

• Contact Giant US directly (giantbicycles.com/us) and explain the situation. They may be able to manually register a European-import bike, or at least flag it as known-legitimate in their system.

• Contact Giant Germany and ask them to issue written proof of registration - a PDF or email confirmation that shows the serial, model, and original sale details. That document should satisfy most US dealers and insurer requirements even if their system doesn't show it.

• US dealers may not need it anyway - for parts ordering, a dealer who can visually confirm the bike model and battery spec should be able to source parts regardless of what their system says about the serial. The battery part number you already have (244M36625I-02V) is what matters there, not the frame serial.

The warranty angle is the one place the regional system really bites - any coverage from Giant Germany is unlikely to transfer to US service centres. Worth checking with Giant Germany whether they'll honour warranty claims on a bike being serviced abroad, but I'd manage expectations on that one.