As a first pass I suggest you model the wheel without spokes, i.e., focus on the hub and rim. For this type of simulation (axi-symmetric components) you can just specify an angular velocity on the rotating components as in the rotating wheel tutorial. This keeps the geometry and physics setup relatively simple.

If you choose to model the spokes then there is no limit on the geometry complexity, but you need to ensure that:

• There are definite intersections at junctions. Having spokes just touch in a tangent condition will cause the meshing to fail. This constraint may make your geometry modeling difficult.
• The rotating spoke region is confined within a cylinder within your outer flow volume. You will then need to construct (connect all faces) a multi-volume flow-domain, so that you can apply a Moving Reference Frame (MRF) condition to the cylinderical volume,
• There is adequate resolution (using the Accuracy tool) of the spokes, likely requiring a massive number of cells, meaning your simulation runtimes will be long

If you are looking to simulate laminar to turbulent transition using the kt-kl-omega turbulence model (as opposed to a wall function-based turbulence model) then you will need to have an even finer mesh on the spokes to make sure you resolve y+ down to ~1.

In summary I think modeling spokes would be a complex process and be time consuming both in interactive model setup and in simulation runtime. I would not recommend this approach unless you are confident that retaining (as opposed to a disk or enclosure) and optimizing spokes is likely to significantly impact your overall design.