We often have riders looking to outfit their road bikes with aerobars for triathlon use. That’s fine, so long as the rider does not try to mimic the geometry of a true triathlon bike. Road bikes have longer top tubes and shallower seat tube angles than tri bikes–thus, when one installs an aerobar on a road bike, the rider will be too stretched out and will slide forward on the saddle, putting pressure on “soft-tissue” instead of on his or her tail bones. It is possible to put on a forward angle seatpost and adjust the stem length to create the same “cockpit” as on a tri bike, but doing so will distribute the rider’s weight forward on the bike, causing the bike to be unstable when in the aero position. (True tri bikes have longer wheelbases to increase stability.) Thus, in mimicking a tri bike position on a road bike, one eliminates everything good about a road bike–the good handling and versatile position–for the sake of getting a not-so-good Tri bike. (The foregoing isn’t to say that there aren’t plenty of riders who are very fast on such bikes.) The problem–and a solution–is illustrated in my more recent blog post, Fundamentals of Triathlon Fit.