The combination of having to turn the cranks far enough to engage a pawl, added to the fact that the outer portion of the mechanism is moving, with the added variable of fairly high speed, could easily result in a delay of 1/8 turn, especially if you also pedal at relatively low rpm's. If by singlespeed you mean fixed gear then yes, you need to get used to a freewheel bike (has nothing to do with whether it's a road bike). Every benefit has a cost.