Currently, the resource headers in TimelineView are vertically stretched to fill the entire space of the control and there is no way to set them with predefined height. If more people request such feature, we will consider implementing it in a future release.
Currently, you can only set their width by using the ResourceHeaderWidth property:
I hope this is useful. In case you have any additional questions, feel free to write back.
Best wishes,
Ivan Todorov
the Telerik team
Q2’11 SP1 of RadControls for WinForms is available for download (see what's new); also available is the Q3'11 Roadmap for Telerik Windows Forms controls.