[Rata]

Other builders get good results from laminating layers to get the required thickness for their wheels. Usually this involves sanding the tread to get a rounded and realistic appearance. I have tried this method but unfortunately the PVA glue I use doesn't sand but if you're one of those builders getting good results this way then keep doing it- when done well these wheels always look better than the 'box' types I'm about to describe.
You can use the 'shark's teeth' tab method to construct wheels but I prefer to do the following. Without tabs there is edge gluing so to give these edges a bit of thickness I laminate another layer under after removing the joiner tab on the 'tread' part as shown. This avoids the four thickness lump at the join point. One tip for beginners is when using a blade and steel rule for cutting straight edges ALWAYS have the part itself UNDER the steel rule. This applies to things like struts on biplanes too.
After joining the ends of the tread part, slide it onto a tapered shaft like a medium size paintbrush handle and press around it with finger tip to get it as round as possible.
Using the trusty Blu Tack, put each wheel side part on the end of a dowel so it's aesier to handle when gluing.
After the wheel is constructed leave it on the dowel and paint out the white edges with matching paint. Most S&P tyres are black which makes life easier.
One of the advantages of wheel fairings is if there's a part of the wheel you're not happy with, you can hide the offending bit inside the fairing.
On this model the wheels are a snug fit which makes positioning much easier. Before the glue sets check the model sits level and adjust either or both wheels accordingly.