How to turn your road bike into a triathlon bike

You’ll ride quicker on the vast majority of triathlon courses if you’re on a triathlon-specific bike rather than a road bike. The trouble is, a triathlon bike costs money and isn’t as versatile as a road bike.

You can’t head out for a group ride with your local cycling club on a triathlon bike, for instance; you need something more manoeuvrable for riding in a pack and a road bike is way more suitable for riding in traffic.

So if you’re only going to buy one bike, a road bike would be the better choice for you.

• The best road bikes for triathlon
• The best triathlon bikes reviewed

Adapting a road bike for race duties is a whole lot cheaper than buying a triathlon bike and you can achieve many of the same aerodynamic advantages.

About 80% of the drag when you’re riding is down to you rather than your bike and/or equipment.

There may be nothing you can do to make your road bike’s frame tubes slice through the air as efficiently as a tri bike’s, but you can make big gains by adjusting your body position. Here’s your guide on how to do just that…

Aerobars

Adding clip-on aerobars to your existing drop handlebars will allow you to lower your torso and create less drag, with your weight resting on your forearms so you can comfortably maintain that position.

Aerobars are usually extremely easy to fit. You simply bolt them to the central section of your handlebar – but bear in mind that some handlebars, carbon ones in particular, aren’t designed to have anything clamped to them and you run the risk of them failing if you fit tri-bars. Check with the manufacturer if you’re in any doubt.

Before you buy tri-bars, check that the clamping diameter matches the diameter of your handlebar.

Manufacturers often make the clamping areas a single size and include shims for use with different types of handlebar, but make sure you err on the safe side.

Some tri-bars come with much more adjustability than others. If you want to experiment with your ride position, buy some that allow you to alter the length of extension and the position of the armrests in relation to that extension – comfort is vital.

Profile Design’s T2+, for instance, give you plenty of scope for fine-tuning.

• What are aerobars?
• When to go down on to the aerobars
• Best clip-on aerobars reviewed

Saddle

A triathlon bike has a steeper seat angle than a road bike. In other words, the saddle on a triathlon bike is further forward in relation to the bottom bracket.

This makes it easier to get into an efficient ride position with your torso parallel to the ground – or close to it.

When you modify a road bike, you don’t have that advantage, so you’ll need to shift your saddle forward.

You could simply move it as far forward as the rails allow on your existing seatpost, but you’re probably better off swapping to a seatpost with less layback (where the clamp sits closer to the centre line of the post).

See our test of the best triathlon saddles for some upgrade inspiration.

Reach

Even if you move the saddle forward, you’ll probably need to adjust the reach to the tri-bars or you’ll end up too stretched. So fit a shorter stem.

As on a tri-specific bike, you’re looking for angles of about 90° between your torso and your upper arm, and the same angle at your elbow.

These are start points, though. If we’d shortened the stem any further or steepened the seat angle any more on the road bike in the picture, we’d have messed up the handling, so we’ve ended up with an elbow angle greater than 90° and it works fine.

Bar height

As on a triathlon bike you need to balance aero efficiency with comfort when adjusting the height of the front end.

Bear in mind that it’s harder to get your torso flat, or near flat, on a road bike than it is on a tri bike, unless you move the saddle forward to steepen the seat angle. You’ll be bending over more sharply to achieve any given upper body position.

If you have headset spacers underneath your stem, it’s easy to move them above the stem to lower the bars. You could swap to a stem with less rise, too.

Remember: a road bike’s head tube is usually longer than the head tube on a triathlon bike of a similar size, so you might not be able to set the front end as low.

And there you have it. All that’s left is to try out your new set-up and position.

Inevitably it’ll feel slightly strange to begin with but that’s all it should feel – strange. If discomfort’s high, change it. It’s worth getting it right as it’s free savings

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Top image credit: Pablo Blazquez Dominguez/Getty Images for Ironman

• Women’s guide to buying a triathlon bike
• Triathlon gear buying guides
• Basic Bike Prep: is your bike ready to race?