You heard it here first...

[ny biker]

astronomic, colossal, considerable, enormous, epic, gigantic, ginormous, humongous, jumbo, mammoth, massive, mega, monster, monumental, prodigious, sizeable, tremendous, vast, very big, very large, whopping, bigger than life, bold, classic, courageous, daring, dauntless, doughty, elevated, epic, exaggerated, fearless, fire-eating, gallant, grand, grandiose, gritty, gutsy, gutty, high-flown, impavid, inflated, intrepid, lion-hearted, mythological, noble, stand tall, stouthearted, unafraid, undaunted, valiant, valorous

-- gnat! (Dude, that ride was fire-eating!)

Hmmm...let's try some of these out...

Dude, that ride was very big!!

Dude, that ride was gutsy!!

Dude, that ride was stouthearted!!

Dude, that ride was lion-hearted!!

Dude, that ride was prodigious!!