Wheelsucker

Stark.

I've heard a lot about how riders reduce the amount of energy they expend by riding in the draft of another. But how close do you need to be before this effect seriously kicks in?

simbil1

Depends on lots of factors but usually you'll want to be within 50cm or so. On a windy day or when descending at speed you can feel the effect several feet back.
Just remember not to cross wheels, if you draft very close it can take a lot of concentration.
Also, it helps if they are 'on your side' in which case they will signal pot holes, parked cars etc.

Uranus

If you're closing up on another rider who's going at a fair speed, then you start to feel the effect from a few metres back. Having ridden hard to catch them, as you close up you will have to ease up, change up a gear, dab the brakes, etc.

But as SIMBIL1 says, the effect gets much stronger the closer you get, so you want to hold station with less than a foot between your front tyre and their back tyre - with attendant dangers if one or other of you is not concentrating :shock:

Monty Dog

The real benefits are drafting are when you're about a foot behind the rider in front, but as said try to avoid overlapping your wheels because if the rider in front moves over, he'll wipe you out. If you brake, be very progressive, not sudden as you'll annoy the rider behind. Try to ride behind an experienced rider, they generally ride smoother and at a more consistent speed and won't make any sudden movements - this will improve your confidence and control. I've taught my two triathlon buddies the art of close bike control - we ride faster and longer as a consequence and they've started getting top-10 finishes too.

mea00csf

huh? but aren't triathlons run as time trials for all races except the elites? You get disqualified for drafting in triathlons. Unless you mean an increase in mileage on training runs. But surely you'd want to train in the conditions you race??