Narrative:

Upon departing [runway] 24L in ZZZZ I called 'positive rate; gear up'. The first officer selected the gear handle to up. A couple seconds after selecting it to up; we both heard a loud bang that came from somewhere behind the cockpit. No adverse flight conditions were noticed nor were there any airframe vibrations. The gear retracted normally as did the flaps. The first officer and I began discussing what might have caused the noise and narrowed it down to one of two potential problems. Either a blown tire or a weight shift. I gave all PF and pm duties to the first officer and contacted the flight attendants to see if they could better locate where the noise had come from. None of the flight attendants reported hearing any noise. We retracted flaps on schedule and continued on our assigned route. Once clearing 10;000 feet; I contacted dispatch and was patched through to [maintenance control]. I then requested that the [chief pilot] be included in the conversation. Without any of us really knowing for sure what the problem was or if there even was one; we all came to the same conclusion that the safest course of action would be to [advise ATC] in ZZZ. The [chief pilot] contacted ZZZZ to see if there was any debris on the runway and there was not. As we checked on with center; I [advised ATC] for a possible blown tire anyways. We had a normal landing and taxied to the gate under our own power after confirming with arff that everything appeared normal. Upon inspection at the gate a ramp supervisor noted that cargo in the aft baggage compartment was not loaded properly and that is was most likely a weight shift that made the noise. The ZZZZ ground crew appeared to be training what appeared to be new hire employees but nobody told us if that was the case.

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Original NASA ASRS Text

Title: B737 Captain reported 'loud bang' after selecting gear up on departure. No adverse flight conditions were noticed.

Narrative: Upon departing [Runway] 24L in ZZZZ I called 'positive rate; gear up'. The First Officer selected the gear handle to up. A couple seconds after selecting it to up; we both heard a loud bang that came from somewhere behind the cockpit. No adverse flight conditions were noticed nor were there any airframe vibrations. The gear retracted normally as did the flaps. The First Officer and I began discussing what might have caused the noise and narrowed it down to one of two potential problems. Either a blown tire or a weight shift. I gave all PF and PM duties to the First Officer and contacted the flight attendants to see if they could better locate where the noise had come from. None of the flight attendants reported hearing any noise. We retracted flaps on schedule and continued on our assigned route. Once clearing 10;000 feet; I contacted Dispatch and was patched through to [Maintenance Control]. I then requested that the [Chief Pilot] be included in the conversation. Without any of us really knowing for sure what the problem was or if there even was one; we all came to the same conclusion that the safest course of action would be to [advise ATC] in ZZZ. The [Chief Pilot] contacted ZZZZ to see if there was any debris on the runway and there was not. As we checked on with Center; I [advised ATC] for a possible blown tire anyways. We had a normal landing and taxied to the gate under our own power after confirming with ARFF that everything appeared normal. Upon inspection at the gate a Ramp Supervisor noted that cargo in the aft baggage compartment was not loaded properly and that is was most likely a weight shift that made the noise. The ZZZZ ground crew appeared to be training what appeared to be new hire employees but nobody told us if that was the case.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.