To rhyme with rubles I presume...
There's a reason why rubble has a double B.
It's absurd; they are all bad attempts to reinvent this wheel;.
ˈtrʌb(ə)l
On the other hand, I gather that spelling contests are only national TV in anglophone countries...
It's quite entertaining to get anyone- particularly a well educated native English speaker- to read this out loud.
"I take it you already know
Of tough and bough and cough and dough
Others may stumble, but not you
On hiccough, thorough, laugh, and through.
And cork and work and card and ward
And font and front and word and sword
Well done! And now you wish, perhaps
To learn of less familiar traps,
Beware of heard, a dreadful word
That looks like beard and sounds like bird.
And dead: it’s said like bed, not bead–
For goodness sakes don’t call it deed.
Watch out for meat and great and threat,
They rhyme with suite and straight and debt.
A moth is not a moth in mother,
Nor both in bother, broth in brother.
And here is not a match for there,
And dear and fear for bear and pear.
And then there’s dose and rose and lose–
Just look them up–and goose and choose,
And do and go, then thwart and cart.
Come, come, I’ve hardly made a start!
A dreadful language?
Man alive! I’d mastered it when I was five."
We also have route pronounced the way Americans pronounce route and the two bits of equipment, a router and a router with different pronunciations.
It depends if it's a modem like thingy where it's pronounced like roux; or a woodworking tool where it's pronounced like row.