Originally Posted by reddog3

This is totally normal on geared bikes. First there's a certain amount of chain slack that must be taken up- then the engagement pawls in the freehub need to "find" the next position in the ramps that can be engaged.

If you put the bike in a workstand (or raise the rear wheel) and turn the cranks- coast- turn the cranks, you'll see times when it engages almost immediately- and other times when it takes a bit of rotation to engage the rear. It's a matter of "lucky" timing.

Sometimes it's disconcerting- especially if coasting at high speeds and you have selected too low a gear for the speed you're traveling. Suppose you've ascended a grade, and coast down the other side without gearing up before reaching speed. It takes a long time to catch up! The rear wheel is simply spinning faster than the hub.

Riding technique can go a long ways toward eliminating the effect. Don't "mash" when going from coasting to pedaling. Instead transition smoothly as you pedal back into engagement. Also, I don't notice much, if any difference in this phenomonon with hubs having more or less engagement pawls or ramps.

The only real way to eliminate this is to go "fixie" and even then you have a certain amount of chain slack to overcome.