After getting my bicycle stolen, I decided it would be a worthwhile investment to buy tracker(s) of various types for my easily stolen goods. As always, Aliexpress comes in clutch offering affordable items that aren’t instanely marked up, here the Sinotrak ST901. This is not yet a review of the Sinotrack ST901 GPS tracker, but may give you some ideas for your motorcycle or bicycle:

Be wary to purchase the 4G model, and do not overpay! It should be around 8-10€

The antenna is integrated in a very compact fashion

The modem and gps(?) modules

Integration into the bike involved some creative fixing. This position was not final, but shows a good location. Be sure to put the antenna (and gps antenna too!) facing the sky.

Size:

Acquiring a sim card is also a bit complex, I am trying to use a prepaid one, tbd how this goes. The online platform is very clunky, and the power draw can be a bit high if you don’t configure the sinotrack to use as little power as possible. To do so, lower the refresh rate, disable 4g unless it receives an sms, and reduce the sensitivity from shock.