The phrase "a clumsy effort" is correct and usable in written English.
It can be used to describe an attempt that is awkward or lacking in skill.
Example: "Despite their good intentions, the presentation was a clumsy effort that failed to engage the audience."
Alternatives: "an awkward attempt" or "a bungled effort".
Mubarak's government was deliberately terrorizing the country's suburban upper class, in a clumsy effort to make the protests look bad.
So even a clumsy effort like "The X Factor" can find a few gems with relative ease.
Yet it was a clumsy effort from Bennett, who missed the ball, and ultimately Sterling was too quick for him.
It was a clumsy effort, and voters saw through it, rejecting that commission's proposals by a 3-to-1 margin.
What was overlooked was the obvious: that Camby, all along ridden so hard by Van Gundy as soft, had snapped in a clumsy effort to prove his mettle.
But the effort to throw the election into a second round was interpreted by the opposition as a clumsy effort by Mr. Milosevic to escape his fate.
In December 1994 Russia began a cruel, clumsy effort to reassert control by carpet-bombing Grozny.A frustrated deal-makerAfter that, Mr Maskhadov often found himself cast in the role of quiet but increasingly marginalised conciliator, doing his best to restrain his wilder compatriots, often unsuccessfully.
Though the novel does a dexterous job of capturing the gossipy, hot-house atmosphere of small town life and though it ably showcases Ms. Dew's gift for delineating children (and the myriad ways they embody and rebel against their parents' expectations), it remains a decidedly clumsy effort, hamstrung by contrived storytelling effects and subsidiary characters who verge on caricature.
My big, lumbering shaggy-dog stuff is a kind of clumsy effort to do what they do in the only style I know.
But I've never seen a film that really made such a good faith, if clumsy, effort to try.
The sporadic shooting heard over the next three hours over the incessant wah-wah of the fire alarm came, in fact, from Swat teams pumping bullets into locked classroom doors in a painfully slow and clumsy effort to track down the killers.
