My Permanent Questions Thread

Wooden centred wheels (properly called Mansell wheels) gave a bit of extra insulation against noise and vibration compared to a solid meal wheel. They only stopped being used when carriages got heavier and required something stronger. Heavier vehicles also require more brake force which requires a wheel that can absorb more heat without being damaged.

John's point also has some validity. Old fashioned railway wheels have a separate tyre that is shrunk onto the centre part (and sometimes additionally secured with rivets). The technology to create a suitable centre part from a metal casting wasn't available in the early years so the wheel centres had to be built up in another way, usually from a number of separate pieces. Later on when casting technology improved it became much easier to make the middle section of the wheels in one piece of metal. Nowadays the whole wheel is usually a single piece of metal without a separate tyre.

https://en.wikipedia.org/wiki/Mansell_wheel
 
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