I’m not the first person to think about concealing an AirTag on my bike to help in its recovery if it is ever stolen. As a result, As a result, there are many commercial products on the market for this purpose. There are products to hide AirTags in the fork, under the saddle, in a bike bell, in a reflector, under the water bottle, etc. The sky is the limit for possible hiding places. In my case, I believe in keeping things simple so I just my found own place to hide my AirTag.
Since using AirTags to find stolen items is becoming more common, some people suggest hiding a second AirTag on your bicycle. Hopefully, if the thief finds one AirTag they will feel safe and stop searching, leaving the second AirTag to help in locating and recovering your bike.
Think about recovering your bike before it is stolen. Many bikes look the same and law enforcement will want to make sure that the bike you claim was stolen from you is indeed your bike. If your bike has a serial number, write it down now. I keep a photo of my bicycle serial number on my phone so that I have the serial number with me at all times. In addition, I keep a copy of the sales receipt at home just in case I need it to prove ownership.