Lots of HOAs have restrictions on parking for RVs and commercial vehicles. It's all laid out in black and white in the CCRs. If the HOA owns the streets as private roads, then they can tell you what you can and can't park in front of your house. However, if the street is owned by the town, then you can park any properly licensed vehicle there.
In the HOA where I live, the rules prohibit parking an RV or commercial vehicle in the driveway. I can park beside the house if there's a gate that shields the vehicle from view. But the street is owned by the town, so I can park on the street. HA!
The OP has a different problem. In his case, it's the town that has the ordinance against parking certain types of vehicles on the street. You can't fight city hall.