For the Chili Sugar Salt Rim:
Mix together equal parts chili powder, cane sugar, and kosher salt. Rub outer rim of glass with lime juice, then dip the wet rim of the glass into the salt mix.
For The Cocktail:
Muddle a lime round in your glass. Shake syrup and juice in a shaker tin with ice. Strain into a glass with new ice, and top with club soda. Stir briefly.