What are the different parts of a triathlon bike?

Here’s a quick guide to the different components that make up a tri bike...


If you want to ride fast, you need to get out of the wind’s way. That’s why the tri bike is the race-day weapon of choice. It’s full of features designed to help you cut through the air as efficiently as possible and make the most of the effort you’re putting into riding. Despite being a similar shape, they can differ quite drastically from road bikes, so here’s a quick guide to what makes up a tri bike…



Di2 battery

The battery that powers Shimano’s Di2 electronic shifting system, from the shifters to the derailleurs.


Usually have small brake levers mounted on the end (with Di2 you’ll also find shifter switches).


There to hold onto in order to maintain some control of the bike when you’re in the aero position. They have shifters mounted on the end so you don’t have to sit up to change gear.

 Arm rests

Pads to rest your lower arms/elbows on when you’re on the extensions.


Connect the front wheel to the handlebars. The steerer tube at the top of the fork goes through the head tube of the bike and is clamped by the stem, which allows you to turn the front wheel with your handlebars.

 Integrated brake 

Most commonly found on tri bikes, the brakes are integrated into the fork at the front and hidden under the bottom bracket at the back to improve the aerodynamics of the bike.

Aero wheels

Wheels that have added carbon sections to improve aerodynamics. Can come in a variety of depths, most commonly between 35-90mm. You can also purchase a solid ‘disc’ wheel at the back.


These days usually 10 or 11 cogs mounted on the freehub of the rear wheel, but can be as few as eight or nine on older bikes. Shifting between sprockets changes the effort needed to move the bike.


The edge of the wheel. The upper part of it is the braking surface, where the brake blocks squeeze the rim in order to slow down. The inner part connects the spokes to the hub.



Join the hub to the rim. They pull the rim inwards at high tension, which makes the wheel extremely strong. If one loosens or breaks, it can imbalance the whole wheel.