Roller of bearing as small handcart
A wheel bearing directly due to the cart, but the outer circle diameter is small, it is difficult to travel in uneven places
Furthermore, cylindrical bearings in contact with the ground will produce indentation increase the resistance, such as silt into the bearing will cause stuck failure at the same time, the noise will be great.
Now, there's an enhanced small wheel on the hardware market that suits your stuff. Just weigh the 170KG at least!
