As a French wheel manufacturer we know our business and justly consider ourselves to be experts in the subject. So we are ideally placed to provide all the information and help you need to ensure you make the right choice. Before changing the wheels fitted to your gate or door there are some essential questions to ask: 1) What is the weight of the gate/door? The weight will determine the number of wheels to be used and their diameter. We offer wheels that have an individual maximum load weight from 25 kg to 900 kg. So for a gate weighing approximately 500 kg you only need two wheels each with a max load weight of 250 kg and a minimum diameter of 90 mm for any easy movement. Always remember that the larger the diameter of your door/gate wheel the easier it will be to open and close. 2) What fixing system should I use? If you are making a door or gate from scratch, the best solution is to purchase the wheel with its mounting and embed it to makes things easier. You can choose to screw it in with a self-tapping screw, bolt it or weld it. On the other hand, if you already have an existing door or gate, the wheel alone with a simple bolt will suffice as you already have the mounting. 3) What sort of groove should I choose? There are 4 types of groove: U-shaped, V-shaped, square and Y-shaped. The U-shaped or round groove is the most common. V-shaped avoids small stones getting caught up in the rail, square is rarely used and finally the Y-shaped groove is very similar to the V. 4) What finish should I choose? For cupboard doors, gates and wide doors we offer a range of different finishes. Bare steel: if you want to paint your wheels the colour of your choice, but bear in mind this type of product rusts very quickly. Bichromated steel: resistant to attack and yellow in colour. Grey zinc-plated steel: as for bichromated steel, resistant to attack. Electro-coated steel: a finish that is both decorative and tough. Acetal resin: the hardest wearing of all the plastics. The CAUJOLLE team of advisers are here to help you at any time, so never hesitate to ask!