That load (gross trailer weight and lumber) adds up to around 450 lbs, and then being able to haul it up a 10% gradient is only made possible by the installation of a Sick Bike Parts shift kit and heavy duty front freewheel bearing because the front chainwheel low range gearing (24 tooth sprocket) on the tetra chainwheel setup places considerable axial loading on the freewheel.
3 years later, and to this day, i still have to pinch myself at just how much punishment the shift kit can take.