There are two different situations that call for remounting the bike: following a running section when the bike is on your shoulder; and following an obstacle when the bike is just lifted up.
After a Running Section
Hold the bars with your left hand and the top tube with your right, then lift the bike off your shoulder and put it on the ground. Try to avoid dropping it too hard, as it can easily bounce out of control, wasting precious time.
1. For a remount with your hands on the tops, use as wide a grip as possible. Also note that Johnson is about to land on the saddle with the very top of the inside of his right thigh, which will give the appearance of "gliding" back on to the bike.
When the bike is on the ground, get both hands on the bars in the position best suited to the next section of the circuit: the drops for a descent; the levers for a climb or any section out of the saddle; or the tops for a relatively smooth section. Then jump on, with as few steps as possible.
You should be able to jump into the saddle smoothly, clip into your pedals, and accelerate as if it were second nature, but problems can arise while clipping your feet in.
If your pedals and shoes are right, then it is simply a question of practice, and this is the most important practice you can do. You should be able to get your feet clipped in ﬁrst time, every time. No excuses!
After an Obstacle
Following the rapid dismount for a hurdle, it is most important to make sure that the bike is under control before you jump on. This means putting it down straight and getting both hands on the bars securely.
This is awkward to do flat-out while trying to take only two steps before remounting, so practice slowly and build up speed, as with dismounting. There are two ways to get your bike over the hurdle as your feet are doing their thing; ideally you should lift the bike up into the air by bending your arms at the elbow.
2. Remounting with your hands on the brake levers makes immediate, out-of-the saddle, fast accelerations to get back up to speed more natural.
Keep the bike as vertically straight as possible so that it will go back onto the ground straight.
When you're getting faster, or when you're traveling too fast to pick up the bike quickly enough, you may tend to flick the bike outward (as if you were trying to show a spectator on the right-hand side of the course the bottom of your wheels).
This is okay, but you must make sure the bike is back on the ground in a vertical plane before you jump back on; otherwise you'll veer off to whichever side the bike is leaning. Good if you know the spectators you are heading for, bad if you don't!