024 IF DUMOULIN WERE THE OWNER OF THIS TIME TRIAL BIKE

Tom Dumoulin during his winning time trial, the 17th stage, Vuelta Espana 2015

Bicycle manufacturer Giant designed the ideal time trial bike for Tom Dumoulin. Many gadgets are not allowed yet by the UCI.

Time Trial bike
Time Trial bike
Aerodynamic bidon
Aerodynamic bidon
Time Trial helmet
Time Trial helmet


A built-in water bottle, a camera on the frame or an extremely aerodynamic position of the rider. Each bike manufacturer has many ideas to improve his time trial bike, but many new things are delayed by the rules of the UCI, the International Cycling Federation. Every bicycle must meet strict requirements. Sponsor Giant, philosophizes with Dumoulin’s mechanic about the ideal time trial bike.

On Service Course of cycling team Giant Alpecin many frames and wheels hung on the wall of a large factory hall, to the wall. Between them also the time trial bike of Dumoulin. Excluding development costs, it is worth ten thousand euros. ( 385.000,00 THB)

The trick of a good time trial bike consists briefly of two steps. Aerodynamics is paramount, because the biggest opponent of a time trial specialist is the air resistance. The perfect posture resembles the shape of an airplane. Along with the bike, the rider must take the form of a water droplet. The front is convex so that the compressed air is able to glide smoothly alongside. Because of the smooth cycle suit and the smooth tubes of the frame the air does not swirl. The end of the drop is a point to let the air flow quietly together behind the bike.

Wind tunnel testing

The shape of a water droplet.

If you look closely Dumoulin’s bike you see all the tubes have the shape of a water droplet. At the front of the frame, the tubes are thick, in order to further toward the rear to be increasingly thinner.

Water droplet
Water droplet

Secondly, all the power to the pedals must be converted into speed. That means that the frame should be as rigid as possible. Exaggerating: the frame of a rider, who rides a frame that is not super rigid, wobbles a bit and that costs speed and energy. Each time trial frame is now made of carbon. Before the frame goes into the oven, carbon looks like mats made of textile. The mats are processed according to a secret recipe to get the right strengths in the right areas of the frame. How the manufacturers do exactly that, is secret. “It’s the tricks of the trade,” according to the Giant’s mechanic. The frame of is built up in a factory in Taiwan, where the brand Giant comes from.

In recent years there have been many innovations in the bicycle industry. The solid rear wheel provides less air resistance than an open wheel and gear changing always goes smoothly with the rise advent of electronic controls. Moreover, almost all the cables of the bicycle are concealed in the frame.

Tony Martin
Tony Martin
Tom Dumoulin
Tom Dumoulin
Fabian Cancellara
Fabian Cancellara


Innovations and technology often come from the aerospace and automobile industries. Mike Burrows is regarded as the founder of Dumoulin’s bike. He comes from Formula 1, and started working 25 years ago at Giant. In Formula 1 carbon was already used, Burrows brought it to the bicycle industry. Burrows designed the bike of Chris Boardman; with this aerodynamic model he cycled in 1996 in one hour 56.375 kilometers. This world hour record was taken away by the UCI because the bike was made too aerodynamic.

Chris Boardman
Chris Boardman


24-14 24-15

Material

Several factors are important for a good time trial. Correct posture on the bike and training are essential. It can thus train. So it can be trained. What you cannot train, important is the choice you make for the right material: aerodynamic modifications to the bike and other stuff like clothes help to reduce wind resistance and therefore save time.

24-16
A notable difference with the standard road bike is the aerobar. This makes it easier to adopt the right posture. A good handlebar is a not a particularly expensive adaptation to the bike, but it delivers a huge advantage in time. Other changes include different wheels, 3-spoke front and at the rear a closed wheel, suit and helmet, with divergent point behind, and another frame. Below we present what profit can be achieved in Watts.

The biggest investments in terms of money are the set of wheels and the frame. With all adjustments you can reach around 75 Watts profit. What does this mean? Imagine riding a regular bike 45 kilometers per hour, then ride the bike with all the adjustments. Your speed will be 50 km per hour. A very big difference.