As would be expected. It really is a red herring to ask “which wheel” or even “which side” when it comes to spoke breakage. Front wheels very rarely break spokes and rear drive side spokes are almost always where spoke breakage occurs.

You will also get tons of people telling you that the problem is “tension”. It isn’t. Or that it’s because you don’t have strong enough rims by which they usually mean heavy rims. That’s not the problem either. The real problem is that you have spokes that aren’t up to the task. If you want to address the problem, actually address the problem and don’t go down rabbit holes that lead you nowhere.

Your spokes are breaking because your wheels are built with the least strong spokes you can buy. OEM wheels are built with 2.0mm straight spokes. It’s counterintuitive but a double butted spoke (2.0/1.8/2.0mm) with a narrower middle section is stronger than an unbutted spoke by about 15% to 20%. If you add 0.3mm to the head of the spoke…2.3/1.8/2.0mm…you increase the strength over a straight spoke by 30% to 50%. This article says that’s the equivalent of adding 10 spokes.

For big people or for little people carrying heavy loads or for big people carrying heavy loads, triple butted spokes are the solution. I suspect that your wheel has a freewheel hub as well. That’s another issue that will eventually raise its ugly head down the road…bent axle…and you might want to address that at the same time as the spokes. Having someone build you a wheel with triple butted spokes…maybe 36 hole…and a freehub will solve your problems nicely. Just about any other solution is only going to result in more broken spokes.