Time Trial Bike

Time trial bikes or trial bikes or TT bikes can be considered as the fastest road bike ever built. Riding one will grant you speed and power. They are also very fancy to look at!

They are more famous as road time trial bikes due to the Tour de France sport, although a lot of people compare them to track bikes that are used in velodromes. This is because road and track time trials look similar to each other.

Features of a Time Trial Bike

All of them are aerodynamic and light. When building a custom time trial bike for pro riders, these 2 factors are often maximized by analyzing them in wind tunnels and then optimized using CFD (Computational Fluid Dynamics) software. A new prototype time trial bike is manufactured. Then, it is tested in the wind tunnel again. Bike companies are constantly improving the aerodynamics of time trial bicycles. New designs emerge from time to time.

Aerofoil Designs

Almost every part of the bike has a thinner profile. This includes the frame tubes, fork, wheels and sometimes even the saddle post. For example, rather than using a rather round shape, the frame tubes are shaped more like an oval, giving it the aerofoil design.

Aerobar Handles (or Time Trial Bar)

Numerous wind tunnel studies have shown that riding with aerobars help decrease drag by about 25 %. However, using these special aerobars require specific frame geometry. Riding with these bars give you the aero position. Most aerobars have gear levers at the end. Riders can reach them and change gears anytime.

Note that there are no drop downs for the wider handlebar's ends. Instead, you will have short "bull horns". The wider handlebars are also thinner.

Frame

The main features of a time trial bike's frame are shorter and sloping head-tube, aero handlebars and aerodynamic frame tubes.

Like the track bike, it has shorter top tube length. This way, you could move more forward and place your hands on the aerobars.

Frame materials are often made from carbon (or carbon fibre) and titanium as they are light. Time trial frames are usually stiffer than usual. But with advancements of technology, stiff materials can be made to absorb shock as well. The reason for high stiffness is so that maximum power transfer from your legs to the wheels is possible.

Its lower tube is also much nearer to the front tire to reduce gaps. Smaller gaps are desirable because rotating tire influences the air movement.

Head tube

The top tube angle is more downwards, depending on design. However, most modern designs have the top tube are straight and parallel with the horizontal ground. This results in a significantly shorter head tube length. What is this feature for? Better stability for handling.

Seat Tube

Like the track bike, the seat tube angle is steep. A steeper seat tube angle allows the rider to go low and more forward, creating a better aerodynamic riding position.

The seat tube is also very close to the rear wheel, looking like it almost touches it. This is to reduce wind drag by closing any gap between the seat tube and rear wheel. This is because a high speed rotating rear wheel can turbulence. Smaller gaps can reduce turbulence.

Fork Rake

For older bikes, the fork rake is reduced. However, most modern designs have a rather straight fork, eliminating any fork rakes.

Front Wheel

You will never find the conventional 36-spoke wheel when it comes to time trials. Time is everything. The front wheel has only a few spokes (sometimes as few as 3). In addition, these spokes are not ordinary spokes. They are slightly larger or thicker, depending on individual company designs.

Like the disc wheel, it also resembles some "disc features" but the disc doesn't cover the entire wheel fully. The "disc feature" measures a couple of inches and starts from the rim. Then, it's all spokes. The standard term used to refer "disc feature" is profile. For example, most time trial front wheels have a 90 mm profile.

Disc Wheel

Most TT bikes have disc wheels for the rear wheel. This type of wheel doesn't have spokes. Instead, like its name, it's a solid disc. It has superior structure compared to wheels with rims. Reason for this design is to reduce wind drag. But disc wheels are at risk in the presence of cross winds. This is why the time trial frames have been built in such a way so that the rider's legs and part of the front chainring block the wheels.

Brakes

There are no brakes at the aerobar ends. You only have brakes at the wider handlebar's ends. Even choice of brakes, whether caliper or V-brakes (cantilever) affect the aerodynamics.

Gears

You will find yourself using very high gears. If you are a spinner (uses high cadence with relatively light gears), you might have to be a masher (cyclist with high gears but lower cadence). Because the course is relatively short (30, 50 or 100 km), you will have to maintain top speed at all times. Using heavy gears ensures consistent top speed.

Tires

The tires are more narrow with smaller widths. These tires are filled with very high pressures, often up to 8 bars (116 psi). On the other hand, professional cyclists are known to inflate their tires with helium gas. The advantage of helium is its lighter weight (compared with air). Using helium gas also means less 10 g of weight for each tire.

Pedals

You will never find toe clips (or straps) in a time trial bicycle. The bike is already high end. This is why professional riders only use clipless pedals. Even something as "trivial" as pedals are so important. Every factor is taken into account when optimizing for the best aerodynamics.

Water Bottle Holder

Despite all the aerodynamics, you still have to drink water for rehydration. Although some bikes in the market designed the water bottle holder to be horizontal instead of being inclined.

Cycling a Time Trial Bike

You will ride in the straightest line as you possibly can. Riding in a straighter path does 2 things; reducing actual distance cycled and maintaining top speed. In short, maximum performance and minimum comfort.

You have to wear special aero helmets. Understand that not all helmets are made for aerodynamics. An aero helmet has a teardrop shape that can reduce wind resistance.

Your elbows will be angled to be 90 degrees or more. This is the most comfortable hand position on the aerobars.

Wearing a pair of cycling sunglasses or goggles is essential. At high speeds, you never want foreign objects to interfere with your eyes.

For further aerodynamics, you have to wear overshoes. Overshoes cover your cycling shoes. As for jerseys, you must wear long sleeves. Your exposed forearm skin will affect your time. In time trials, every second matter.

If you are competing in an individual time trial stage competition, a good advice is just pedal as hard as you can non-stop. Remember, you are alone. There are no team strategies to contemplate. Ride the "race of truth", as most people call it.

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