Originally Posted by
topflightpro
A 24-ounce bottle weighs about 1.56 lbs or about 710 grams, while a 21-ounce bottle weights about 1.365 lbs or 620 grams.
Going from Rival to Red will save you about 320 grams, about half a small bottle and not quite half a large bottle.
You're a little light on the water weights (water is 8 1/3 pounds per gallon rather than 8), plus you need to add the weight of the water bottles themselves.
But the concept is sound. Spend another $1,500 on upgraded cockpit and wheels, and you've maybe killed off the whole water bottle.