The American revolution seems to have been a pretty middle-class affair. The Czech(oslovakian) "Velvet Revolution" and the Estonian "Singing Revolution" too, I think. [EDITED to add:] In so far as there can be said to be a middle class in a communist state.
Yeah, Eastern Europe / Russia is an interesting case. First, as you mention, it's unclear to what degree we can speak of the middle class there during the Soviet times. Second, some "revolutions" there were velvet primarily because the previous power structures essentially imploded leaving vacuum in their place -- there was no one to fight. However not all of them were and the notable post-Soviet power struggle in the Ukraine (the "orange revolution") was protracted and somewhat violent.
So... it's complicated? X-)
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