The title of this will confuse many, how could a triathlon bike slow you down? They’re more aerodynamic, which means they’re faster, and all of the pros race them in non draft legal races, how could a triathlon bike slow you down?
If a triathlon bike was the outright fastest and most comfortable way to get round, why wouldn’t people ride them all the time? The answer is a triathlon bike involves a lot of compromises in the way of bike design, and they can be difficult to get comfortable on, something those of you who have ridden one can likely attest to.
For those who need a basic explanation, a triathlon bike makes you faster by lowering and narrowing your profile against the wind. The bike frame itself is also tapered to make it cut through the air as fast as possible, but as the least aerodynamic thing on the bike is you, the focus is on getting yourself lower and narrower. Most have shifters on the bar ends and electronic models also have shifters on the bullhorns to make it easier to change gear when braking, climbing or descending.
The compromise is that to improve airflow around the bike the frame, more material is needed to reduce turbulence, which results in a bulkier frame, increasing weight. On a pan flat course this isn’t a problem, but if you find yourself on an undulating course this can become an issue. Not only does this increase weight when climbing, but it makes the bike less stable on the descents, which combined with the fact that brakes on triathlon bikes are normally less efficient than on road bikes, can lead to you handing over minutes to those on the road bikes on the hills. If you can make that time back on the flats you’ll be faster overall, but if a course is especially hilly you may be better off going for a light, responsive climbing bike.
There is also the question of wheels, most stock triathlon bikes will come with a very basic set of wheels to make the price point more appealing, but most triathletes will upgrade the wheels into something more aerodynamic such as a rear disk wheel or deep section rims. These are not only heavier and slower to accelerate but are a handful in crosswinds, to the extent that certain courses especially prone to strong winds ban them. If you are on a flat piece of road in good conditions they can shave minutes off of your bike split, but they’re not always the right choice.
You also need to be going at a fair rate of knots for the aerodynamic benefit to really kick in, around 30-35KM/H depending on the course. Can you maintain that speed for the duration of the bike course? Chances are that on shorter distances you can, but over half iron or full iron distances you really need to be able to ride a bike well to reap the rewards of a tricked out triathlon bike.
Along with ability to maintain speed is also the question of core strength. While properly setup aero bars can be very comfortable as your weight rests on the elbow pads, you need to make sure you have the core strength to maintain that position for the duration of your race, as you will be in a plank like position. If your core collapses in the bike leg your run will likely be a disaster as your can’t support your body in an economical position, adopting what many call the “Ironman shuffle”.
If you race on your triathlon bike you really need to train on it. That’s not to say that you should bin your road bike, as it is important for group riding sessions (which I believe are an excellent way of building bike fitness), but you should stick your race bike on your turbo over winter and take it out at least once a week in the spring to get used to handling it on the road. You should get used to riding on all conditions in all terrain on your race bike, whether it’s descending down a steep hill in the rain or threading it through a series of fast corners, you need to be confident in your handling ability to minimise time loss in the hills.
You should also put it in for a full professional service at least once a year, clunky gear changes will not only frustrate you but lose you time hand over fist, not to mention the possibility of pieces falling off! I it is also important to re-index your gears when you re-build your bike on race day. Whether your flew it halfway round the world or stuck it in the boot of your car for the local sprint race, it doesn’t take much for your gears to take a knock and play havoc with your race.
Most importantly, make sure to get a proper bike fit to get yourself into a comfortable and economical position. Your aerodynamic position may save you 25W, but if you’re putting out 50W less than on your road bike because you’re not used to the position (which engages your hamstrings and glutes far more than a road bike position) you’re actually going slower than on a road bike. Your position doesn’t necessarily have to be as far forward and as low as possible, look at the picture below of the Great Britain men’s team pursuit squad at the 2016 World Track Championships.
Notice the variation in width of the aero bars and the height of the stack, there’s no ideal position as it’s very individual. Of course not all of us can afford £2500 to spend in the wind tunnel finding our optimal position, but notice how they’re not as low and as narrow as possible. I personally find having my bars close enough for the knuckles of my thumbs to rub actually makes me more stable than having them wide, but it’s very individual, and comfort is king. If you’re comfortable you’ll be able to put out more power for longer, if you’re scrunched up and can’t breathe properly, you’re just handing advantage to your rivals.
Just to add to the confusion, a lot of professionals will take a triathlon bike even on a very hilly course. This is because they’re exceptional athletes who can handle a bike better and put out more power than most of us ever will, allowing them to still put out some serious watts on the flats where most of us would struggle as our legs are trashed from the hills. Just because Daniela Ryf can pull it off, doesn’t mean you can.
In the Tour de France where they use both road and aero bikes in competition, some will even put clip on aero bars onto their road bike to offer the best of both worlds in mountainous time trials. This offers a sizeable advantage without any of the drawbacks of a full aero bike, but when using clip ons we have to reach away from the bars to the STI shifters to change gear, increasing our profile against the wind and slowing us down. They’re a great option for hilly races or for trying an aero position without buying a whole bike, but it involves a number of compromises so should be carefully considered before taking to a big race.
So to summarise, a triathlon bike will take minutes off of your triathlon time if you are accustomed to riding in an aero position, it is perfectly setup for you, you have the core strength to maintain the position, the course is flat, and you have the strength/endurance to hold high speeds for the duration of the bike. If however a triathlon bike is just something you throw your leg over on race day, the benefits will be much smaller than you expect, and in some cases may even slow you down compared to your tried and tested road bike.
If you have a triathlon bike and are looking to unlock it’s full potential, organise a 1 on 1 coached session with me for only £30. E-mail firstname.lastname@example.org to register your interest