Loose wheel with PP hub and PUR tread

Loose wheel in PUR with the hub in polypropylene

This is a loose wheel with a running surface in polyurethane and a hub in polypropylene, meant for lighter transport and equipment where the wheel is to sit directly on its own axle without a bracket. The tread is cast PU with a hardness of 98 degrees Shore A, that is at the harder end of the polyurethane scale. That gives a running surface that holds its shape well and takes load without deforming noticeably.

A harder PU tread rolls easily. The rolling resistance stays low since the tread does not sink into the surface, and the wheel gets going with little force even on a smooth floor. At the same time the polyurethane spares the floor considerably more than a wheel in hard plastic; it grips better and normally leaves no marks on painted or ground concrete. PU also takes most oils, greases and mild chemicals found in a workshop.

If you want to compare: a softer rubber or elastomer wheel damps more and runs more quietly over joints, but loses load capacity and drives up the rolling resistance. An even harder wheel in pure plastic rolls more frugally but is noisy and can scratch sensitive surfaces. This PU tread at 98 Shore A lands in between: hard enough to roll efficiently, elastic enough to spare the floor.

The hub in polypropylene is light and corrosion free, which keeps the weight of the wheel down and makes it indifferent to moisture and cleaning agents. The wheel comes with two bearing options. The plain bearing is simple and maintenance free, takes dirt and wet and suits where the wheel rolls seldom or slowly. The ball bearing gives lower rolling resistance and a smoother run where the wheel moves often or over longer distances.

The wheels come in diameters from 27 to 100 mm and handle load capacities up to 55 kg per wheel. A larger diameter rolls more easily over thresholds and joints and lowers the rolling resistance, while a smaller one keeps the overall height down where space is tight. Since the wheel is supplied without a bracket it is mounted straight onto its own axle through the hub, which makes it easy to build into a machine or a special design.

Where does it fit? A loose PU wheel with a PP hub often sits on equipment, lighter internal carts, machine underframes and fixtures where you build your own axle solution. The harder tread and the low rolling resistance make it a good choice where goods are to be moved smoothly without wearing on the floor. The low weight and the corrosion free hub also make it useful in damp spaces and where the wheel is cleaned often.

Think about the operating environment. Polyurethane is happiest at normal indoor temperature and in dry to slightly damp environments. If the wheel stands still for a long time under full load, the tread can take a temporary flat spot that rolls out after a while; that is normal for cast PU. The limited load capacity makes the wheel less suited to really heavy loads, where a wheel with a metal hub fits better.

Are you unsure which diameter and which bearing suits your axle and your load? Get in touch and we will go through the load and the surface together.