Assuming it's not an event run under UCI rules, a disc cover is the most cost effective answer. About $100. It will make a measurable difference in speed.
And unless it's a very hilly course, the speed advantage will trump the weight.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.