The closing date for this event has now been extended until Wednesday 19th June as it sin't on the main BSCA website.
Entry Form is below with age categories etc.
Grass Entry Form
GRASS TRACK - Competitors in Regional and National Championships must
use a machine with a single fixed gear and may not have brakes or any
dangerous projection. This rule does not apply to under 7′s, under 9′s
under 11′s, and under 13′s who must use free wheel machines. The use of
Spinache style bars shall not be permitted in massed start races.