The phrase "a flimsy one" is correct and usable in written English.
It can be used to describe something that is weak, insubstantial, or lacking in strength or support, often in reference to an argument, excuse, or object.
Example: "His explanation for being late was a flimsy one, lacking any real justification."
Alternatives: "a weak one" or "an insubstantial one."
Their criticism of Ms Spielman for lacking "passion" is a flimsy one based on the style of her response to questions, not the substance of her answers.
But at least a roof shelters their heads, even if a flimsy one that allows the rain to pour through.
Your question gives us an excuse -- a flimsy one -- to mention that at 597 feet, the Board of Education radio tower, which was built in 1938, is the tallest structure in Brooklyn.
The Alberta group was taken aback by the pointed Avatar attack, considering the comparison to be a flimsy one.
This crisis seems like an excuse--and a flimsy one, at that--to put distance between the U.S. and Israel.
Smith has a folder for her receipts, too, but it's a flimsy one, from which paper escapes and gets lost.
The hospital was on the town's outskirts, a flimsy one-story construction that looked like a rural elementary school.
If you're running a conference, would you rather pay for a flimsy one-off app, or get paid to use a data-driven one your attendees may already have?
The group of eight breakaway Democrats in the state Senate caucused with Republicans, guaranteeing a conservative majority in the chamber ― now only one holdout, Brooklyn Democrat Simcha Felder, has left Republicans with a flimsy one-vote majority.
Nonstick makes it easier, but it has to be a heavy nonstick pan, not a cheap, flimsy one.
Part of the problem is that MacFarlane doesn't seem to have added too much to the film script, so this is a novella-length novel and a noticeably flimsy one, lacking detail and context.
