Originally Posted by B. Santos

C-Hubs are a must for spares.

The TB-04R comes with Part #54580 - "Carbon Reinforced Hub Carriers". These seem to break easily if your track uses boards and you come in contact with them often.

Most folks here seem to recommend Part #51293 - "TA05-IFS F Parts (Hub Carrier, 4 degrees)" as a much more durable alternative. To use these you also need a 3x0.7mm shim (Part #19805645) to sandwich in-between the top of the front upright and the top flange tube in the c-hub.

The TA05 hubs are not as rigid as the stock reinforced hubs, but I don't notice any difference in steering.