Giving your road bike some triathlon-friendly adjustments may be the way to go when first entering the sport.
Teardrop tubes and pitchfork handlebars are the most noticeable differences between road bikes and tri bikes, but frame geometry—the way a frame positions the rider’s body—is the most important difference. Triathlon geometry is designed for riding as fast and efficiently in a straight line as possible. If you add aerobars to a road bike, you’ll want to change the rest of the bike’s fit (best done by a professional) to accommodate your new position.
Move the saddle forward. Sliding the saddle forward on the rails can help a little, but using a forward-oriented seat post further replicates a tri bike. Find a forward-set post such as the Profile Design Fast Forward or one that can be flipped forward, like the Bontrager Race Lite seat post.
Find a comfortable seat. Dropping into aerobars redistributes pressure onto different parts of your undercarriage, so a saddle that’s comfortable in a road position might not work in a triathlon position. Find a saddle that feels best for you—some tri-specific shops will let you try various models on a fit bike in the store.
Position the aerobars. The location of the aerobar grips and elbow pads have a significant impact on fit. Get a professional fit before picking your new aerobars to find a pair that allows your body to sit in your preferred position rather than contorting to accommodate the bars. Adding aerobars also has several subtle influences on position, and a good bike fitter will address those subtleties to ensure comfort.
Other tri gear questions:
What are triathlon-specific shoes? Tri-specific running and cycling shoes are versions of their single-sport relatives adapted for quick transitions. Until you’re interested in saving seconds, regular running and cycling shoes will do the job.
Why aerobars? Aerobars are for going fast. Leaning elbows-first against the handlebars might look more comfortable, but many riders find it easier to quickly get comfortable riding in a road position. Get aerobars if you want to ride faster or go the same speed using less energy.
What is a race belt? A clipable race belt prevents wasting time with safety pins in transition. You can find one for less than $10.