There’s a lot more to sprinting than just gunning it as hard as you can at the end of a race. There is of course the physical raw speed and power of the sprint, but there is also positioning, and some technique.
First, there are those who are natural sprinters and those who are not. If you are among the many that are not, you need to train yourself to gain a sprint. You may never be as fast as the natural sprinter, but some work at it will help you to better placings and wins. Some sprinting ability is naturally better than none at all.
The main ability that natural sprinters possess that most of the rest of us do not is accelerating throughout the sprint. The non-sprinter will start a sprint with a sharp acceleration, and the speed then tends to stay the same throughout the sprint. The sprinter will accelerate sharply, and continue to accelerate all the way to the line.
What the non-sprinter needs to do in training is to learn to continue accelerating. This is usually more of a problem with leg speed rather than power. Most non-sprinters have plenty of power, but simply need to train themselves to apply that power to a sprinting situation. The biggest mistake in training for sprints is (here it is again) to use too big a gear. By training for sprints in a large gear, you merely reinforce the habits that make you a less effective sprinter. The trick in training for sprints is to use a light gear you can accelerate with relative ease, and continue to accelerate throughout the sprint.
For the non-sprinter, find a 250m stretch of road with a slightly downhill approach and that is relatively free of distraction (intersections etc.). Come into the sprint at normal riding rpms and at the start of the 200m stretch, without shifting, stand a bit to accelerate sharply. Once you’ve accelerated as much as you can standing, sit down and work on continuing to accelerate. If you find yourself unable to continue accelerating, you’re using too big a gear. Do a set number of these (say, maybe 6-10), and you’re sprinting will improve, I promise. It won’t turn you into a mass dash master, but it will give you something to fight with.
Another method to improve sprinting, also very useful to the natural sprinter, are short uphill ‘power sprints’. I would caution that these should only be used once you’ve gained good form…say, a month or two after you’ve begun quality training. While the light gear leg speed sprint workout isn’t too terribly onerous in terms of workload, the uphill power sprints are very taxing. Find a 150-200m steep hill with (preferably) a downhill approach (a flat approach will do if need be. Also, its better if the hill gets gradually steeper toward the top). Roll into the hill with good speed on a medium big gear and accelerate sharply just before the hill begins. Here the idea isn’t to continue accelerating, but to continually increase the power output throughout the sprint (if only a little). Without a power meter to determine this, you can tell you’re increasing the power output if you can keep the effort going while staying ‘on top of’ the gear you’re in. If you can’t find a gear that you can ‘stay on top’ of, or you can’t keep the power going up, you’re probably not ready for this particular drill. Put it off for a few weeks and try again.
Positioning for the sprint is every bit as important as having the ability to sprint. Obviously, if you’re out of position, you won’t be able to use your sprint, no matter how good or bad it is.
When the entire bunch is coming to line together positioning yourself can be more about luck than fitness. You could seemingly be in the perfect spot with 500m to go, and get swarmed on the other side. To keep position, you have to take chances and have a bit of luck. It is of course important not to take dangerous chances (trying to push into holes that aren’t there), but take calculated chances. It is of course better if you have teammates to keep the bunch fast and strung out close to the finish, but this isn’t an easy thing to do, and it requires a strong understanding as to who the team’s sprinter is, or for whom they want to get a result.
Positioning for a sprint from a smaller bunch will depend on the situation. Sometimes being second wheel is best; sometimes it’s better to be at the back of a 6-rider group. Recognizing where it’s best to be is a matter of experience, and knowing your sprinting abilities vs. others. Some generalities though: If the sprint is a tailwind, or slightly downhill, go for a longer sprint. The reason to go longer is that the speed will be higher in a tailwind or downhill. If you reach top speed early and it’s easier to keep that speed because of the gravity/wind assist, it will be harder (by the laws of physics and mathematics) for someone to get by you. On the opposite end of the spectrum, in a headwind or uphill, you want to start your sprint much later (shorter). If there is an impediment to speed, it will be more difficult to maintain or increase your speed throughout the sprint. Riders in your draft will have a very good chance to accelerate and get around you late. Also take note of which direction the wind is blowing at the finish. Sprint on the side of the road where no one can take advantage of your draft.
Positioning is easier if your team has a lead-out organized. In a small group, the sprinter stays immediately behind the lead-out rider. From 450m to 200m to go the lead-out rider should be sprinting as if the 200m to go sign is the finish (with a less sharp initial acceleration). The idea of the lead-out is to deliver your sprinter a clear line to the finish, at such a speed that it will be too difficult for anyone to come around. About 10m before the 200m sign, the lead-out rider should move gradually a bit to the left or right depending on which side the wind is coming from (if the wind is blowing from the right, you would move right to protect your sprinter). The more teammates you have, the earlier the lead-out process can begin. Don’t start the process to early, lest you burn yourselves out and can’t deliver a fast enough lead-out for the last 500m.
First, standing or sitting? Sitting is faster in general but for the initial acceleration standing will usually provide a sharper initial acceleration. Once that initial acceleration is finished, however, get back in the saddle and keep accelerating. On steeper uphill sprints, standing all the way may work best, depending on how steep it is.
The only other technique point is upper body use. Use your arms like a fulcrum, as if you were trying to pull your handlebars into your chest, and hold your torso rigid. Do this throughout the sprint, whether you are standing or sitting. Finally, you will get more leverage out of your bars if you are in the drops. If you’re up on the hoods you will be more stretched out and less able to leverage your body.
I will also point out here that while the track is a good place to work on sprinting; sprinting is an entirely different ballgame on the road. Momentum and positioning is more important on the track while power takes more of forefront role on the road.