Thinking about a triathlon bike for next season? Or maybe adding aero bars to your road, here are some thoughts from Blue Competition Cycles.
Everyone knows you can go faster by increasing your power output on the bicycle. Those who are into triathlon have spent hundreds, if not thousands of hours working to improve their power and efficiency on the bike. But a missing element for many is how to improve their speed on the bicycle at the same power. Aerodynamics holds the key to getting a faster bike split – wind drag is the number one force against you and prevents you from going faster on the bike. It’s not tire friction or the weight of the bicycle that matters most but the air force against the forward motion that slows you down. Wind drag increases exponentially with an increase in speed, so, in order to go only a few miles per hour faster you have to overcome a greater force.
Many people start off on a road bike for their first triathlon, maybe next they transition to the road bike with aero bars and then make the leap and buy a triathlon bike. Each time they think it means they will go faster. The real results they see may not change much or they may be going a bit faster because they have now put in more training and have some experience. Some people would be surprised to find they are riding in a non-ideal position for aerodynamics even on a triathlon bike. In order to maximize speed you have to understand how body position plays a key role.
The two primary ways to go faster are to 1. increase the power on the pedals and 2. increase aerodynamics. The trick seems to be doing one without hurting the other.
Lets look at the aerodynamic aspects of both the body and the bike. An example of a bicycle designed to maximize aerodynamics is the latest on the market for BLUE Competition Cycles the Triad Elite. This triathlon superbike utilizes SFT2 (Super Flow Tube Technology) tube shapes that are narrow and wing-shaped. The SFT2 carbon-fiber tubes slip through the wind easier as they allow air to flow over the tubes like the wing of a plane. This bike has aero covers on the front brake to reduce frontal area drag combined with an aero cover over the bottom bracket and rear brake to increase aerodynamics even further. While an aero bicycle will shave time off your Ironman bike split in order to maximize aerodynamics your body needs to also be more aero. This means your torso is in a horizontal position compared to the direction of the air flow and your head is lower than your shoulders. When you get in this position however their are several issues that come up regarding bike fit that may reduce your power with a net zero increase in speed. If you try to get in an aero position on a standard road bike your hips are not tilted forward so it is difficult to lean very far forward. A triathlon bicycle like the BLUE Triad Elite has a steeper seat tube angle than a traditional road bike. This steeper angle allows you to be more directly over the bottom bracket instead of behind it like on a road bike. This helps push your hips into a forward position allowing you to bend forward more and be lower on the front of the bicycle and utilize a lower handlebar position. As an example of the savings for estimation purposes we used a bicycle power vs. speed calculator to see the speed difference of riding a road bike vs an aero triathlon bike in a 112 mile Ironman bike leg. A 150lb rider producing 200 watts on a road bike in a more upright position would take between 5 hrs 20 min to 5 hrs 40 min (making some broad assumptions about factors such as wind and terrain). The same rider outputting the same power on a triathlon bike in an optimized aero position could ride it in 4 hrs 54 min to 5 hrs 10 min. Even if the rider had slightly less power in the triathlon position they are still going substantially faster. As a reference point if the same rider’s road bike was 1lb. lighter than their triathlon bike it would only shave 1 minute from their bike time.
The additional benefit to this “triathlon” position is it allows you to utilize your hamstrings and gluts on the bike so that your quads are not doing all the work. Done correctly this can help in that dreaded transition from bike to run so that your quad muscles are fresher for the run part of the race. A critical aspect to a good aero position is a balance between aerodynamics and power. Since you are leaned forward more you don’t want to decrease the angle between your torso and thigh so much that you lose power at the top of the pedal stroke. It is not an easy combination to figure out but a bike fit expert can help you setup your triathlon bike to maximize your power and increase aerodynamics.
If you ever find yourself riding along on the Queen K highway in early October surrounded by three or four Ironman Champions, you better hope you are riding a fast bike and in the best position possible. Why? Because you know you are going to have one heck of a race on your hands and going to need several things to go your way. You are going to need to save as much energy for that run to follow and you are going to need to come off the bike able to use that energy you saved.