The phrase 'bulky of' is not correct and not usable in written English.
It is not a phrase that is used commonly in the English language. If you were to use it, it would not make sense in the sentence.
She found the coat the least bulky of the group.
It's probably the least bulky of the heavy-duty cases on the market and does not impede the phone's functionality.
It's big and bulky, of course, but it turns smoothly into corners, it hangs on to the road and soaks up bumps beautifully.
Theirs was the least bulky of the bodybuilding categories — which rose, in order of ascending mass, from Bikini to Figure to Fitness to Ms. International — but they looked as sinewy as velociraptors.
But despite all the high-tech gizmos crammed inside them, like laser pickups and computerized decoders, portable CD players played music on the go about as well as an old-fashioned record player, not quite as bulky, of course, but with a similar problem: whenever a CD player was moved or bumped, even a little, it skipped.
It's more bulky, of course, and less cool-looking, but if you've got to carry a lot of stuff, it looks like it'll get the job done.
Around the shore I caught sight of the impressively bulky headland of the Mull of Kintyre.
Carl Hall, the bulkier of the two, had converted the game's first layup.
The bulkiest of the sailors stood on a suitcase and pulled himself through the window as far as his waist.
"You feel a little like a walking snowman while wearing it," she said about this jacket, which she thought was the biggest and bulkiest of the bunch.
One of them, the bulkier of the pair, has planted his foot on that of the other one, who is, on closer inspection, better dressed.
