There is no lock that is going to guarantee the bike is safe from theft. Many riders use both a U-lock and cable. That allows the bike to be locked to something and the cable run through the wheels. I have seen the cable also run through the chain rings. I know nothing about bike alarms. There are threads on these forums regarding bike locks.
Last edited by delbiker1; 06-30-19 at 07:23 AM.
Reason: spelling/language