7Kinesins are molecular motors that walk along microtubules, hauling cargo through the 8 crowded cytoplasm of eukaryotic cells. At low load, kinesins almost always step towards 9 Significance statement 1 Kinesin-1 molecular motors typically walk towards microtubule plus ends. Under load 2 however, backsteps also occur. Backsteps have previously been thought to occur by 3 directional reversal of forwards walking. We report that kinesin waits before forward steps 4 for less time than before backsteps and detachments, that it waits for the same amount of time 5 before backsteps and detachments, and that the relative numbers of backsteps and 6 detachments can be shifted experimentally without affecting forward stepping. As we 7 discuss, this argues for a mechanism in which motors that fail to step forward within a time 8 window can slip back, re-engage, and retry forward stepping. Our findings speak to the 9 mechanisms of directional bias and mechanochemical coupling in kinesins, and potentially 10 other motors. 11 12