My norm for quite a while has been 2 single bikes - gotta have a backup bike - plus 1 tandem shared with spouse. Have had brief periods of owning 3 single bikes. And owned 2 tandems for a short time.
Guitars? I have 2. Have never owned more than 3 and there were times of 1 guitar in my past.
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Bacchetta Giro A20, RANS V-Rex, RANS Screamer