Doors and windows that open and close by a sideways movement usually depend on roller bearing components to provide the smooth action required.
There are two main types: overhead track systems and base mounted systems. The weight of the joinery unit supported on the roller bearings dictates what bearing unit should be used.
It is best to buy high quality roller bearings at the time of purchasing the joinery. The advantages are that you will be offered rollers that are designed for the unit they are fitted into and they will be factory aligned to operate without undue wear, ensuring trouble-free service.
Upgrading rollers later may be difficult, especially if the fixing points are different to the original.
Consider the following when consulting with your supplier:
The Industry is currently developing new standards for rollers. We will post the specification reference on this site when complete.