2024 surron ultrabee

want my ultrabee to go faster top end, hits 96kmh pinned on flat ground, 100 downhill.

has anyone put a few different sprockets on there one? what are your best results? and how fast have you got on flat ground… stock powertrain

would like to get it to go as fast as possible

what size sprocket would you guys recommend and do i need to buy a new chain or just change the length of mine please educate me, cheers