Perhaps industrial rotary bearings like these https://www.accu.co.uk/en/539-rotary-bearings could be made in a similar fashion for the bikes, i.e. precision machined. The precision machining would be smoother compared to standard bearings and last longer than ceramic.
Perhaps industrial rotary bearings like these https://www.accu.co.uk/en/539-rotary-bearings could be made in a similar fashion for the bikes, i.e. precision machined. The precision machining would be smoother compared to standard bearings and last longer than ceramic.