I think I’ve found the best place to hide a tracker on my Brompton: in its front carrier block!
It does require a Pebblebee Tag, as AirTag and Chipolo One are too big to fit. Just make sure to leave a space on top for the locking mechanism to fit.
Edit: I was told that AirTags fit as well, so I guess Motorola Moto Tag might fit too, as I believe they are roughly the size of AirTags.
I’m unfamiliar with the brand but I assume the part you are showing is solid metal?
If so, the tag isn’t going to be able to broadcast very far. You better hope the person that steals it has their tag tracking settings enabled on their phone.
@Blue_Morpho I don’t think it would interfere with the signal as the carrier block is mostly made of plastic. I haven’t tried the range yet, but I’m not too worried.