Weak lemonade or limeade made with a minimal amount of sugar and a generous pinch of
for potassium and sodium. Green tea with a shot of lemon juice and honey, and a pinch of the Morton lite salt works as well.
Alternatively, you can just drink water and get your electrolytes from food sources. A combination of lightly salted almonds (Blue Diamond has a lite sea salt roasted almond that is quite tasty) and some dried fruit like raisins, craisins, berries, dates or figs will give you all the sodium, potassium, calcium and magnesium you need as long as you maintain appropriate hydration. You can buy commercial, or make homemade, granola that includes the almonds, fruit, and some coarse rolled oats. Even oatmeal raisin cookies provide everything a cyclist needs as far as electrolytes and carbs.
In this age of sports gels, drinks, blocks and beans we seem to have forgotten that real whole foods are still a perfectly acceptable source of nutrition, including electrolytes.