Someone starting out in the sport they may wonder what a triathlon bike is. Any bike that you ride at a triathlon could be considered to be a triathlon bike. However this phrase tends to refer to a specific kind of bike which is optimised for use in a triathlon.
I want to start off by reassuring you that you do NOT need a triathlon bike to participate in the sport. They are expensive, difficult to ride and are generally reserved for those already racing at a relatively high level in the sport.
You can see a visual example of a triathlon bike below.
This is very different to your average bike, so let’s break down the features of a triathlon bike.
Handlebars replaced with aero cockpit
If you are used to hybrid or mountain bikes, you will probably have ridden bikes with wide, flat handlebars for stability. Meanwhile, a road bike (such as the one below) will have what we call dropped handlebars.
These handlebars are narrower, and allow you to ride in a more aggressive position. The rider in the picture above is riding on the hoods, where he has easy access to his brakes and gears. He can also ride on the drops, by placing his hands on the curved sections. This is a slightly faster position, but it does affect access to the brakes and gears.
Meanwhile, a triathlon bike will have a completely different setup. The handlebars and replaced with a base bar and aero bars. This is sometimes referred to as a cockpit.
In this position we do not have access to our brakes(!). We lay our elbows on the pads, and hold onto the bar for stability. This is known as being in an aero position, or simply “in aero”.
The reason for this is that it places us in a very aerodynamic position. This vastly reduces the drag we encounter when cycling. As air resistance is the biggest factor that slows cyclists down. Tucking ourselves into a lower, more narrow position makes us notably faster for less effort.
The downside to this is that the position is a lot twitchier. You won’t have access to the brakes either, and it places strain on our neck. These are all factors which you will adapt to over time, but it will take several rides on a triathlon bike before you are confident enough to ride it at the speeds required to gain an advantage.
When you need to go round a tight corner or brake, you need to break from this position. Over time this will become easy, but it is intimidating to start with.
If you’re too scared to go fast in the aero position, you will be faster on a road bike.
Tapered frame
The majority of bikes are constructed with rounded tubes. These provide a good level of durability and are cheap to manufacture.
Triathlon bikes (and certain road bikes) are instead manufactured with a tapered frame. This helps improve airflow around the frame. When riding solo as you will in a triathlon, this will help you ride faster for the same effort due to improved aerodynamics. Between the riding position and the tapered frame, everything about a triathlon bike is designed with aerodynamics in mind.
However, the bike frame only accounts for around 10% of drag, with the rider making up the other 90%. So a frame that is marketed as being 10% faster than the competition will still only provide you with a 1% improvement in overall speed. If said bike is £3000 more expensive, you have to take a long hard look at whether it is the best place to spend your money.
Storage
Some top end triathlon bikes come with a storage compartment in the frame. This allows you to store tools, clothing, nutrition or anything else you’d like to cart around with you during the bike leg.
These are not especially spacious, but do provide a very aerodynamic solution. Triathlon suits have very limited pockets to avoid creating drag in the swim. This makes difficult to take equipment with you. If you are taking on an IRONMAN, you cannot afford to head out with what you need to confidently complete the bike. The storage within a triathlon bike is a great way to achieve this.
Integrated bladder
Carrying enough fluids to get you round a bike course without dehydration can be challenging. You can place bottles on the downtime and seat tube, but this causes a lot of aerodynamic drag. There are solutions involving bottles mounted in the aero bars or behind the saddle, but these can be fiddly to use. Watching professional athletes race, some of them struggle to replace their bottled into rear mounted hydration systems.
Some triathlon bikes include an integrated bladder which allow you to drink through a conveniently placed straw. This is the perfect solution, in many respects, but it does come with a couple of considerations.
For a start it is slow and difficult to refill on the go. You probably don’t want to be stood stationary at an aid station slowly emptying the contents of a bottle into your bladder. You want to be able to grab a bottle and go. Over shorter races this is less of an issue, but over a longer event you will need to pair it with traditional bottle systems.
The second issue is cleaning it. You need to dry it carefully after using it to prevent mildew. If you fill it with sugary carb mix this is going to involve quite a complex process to get it clean. I recommend only using it for water during training rides, and keeping the carb mix out of it until race day.
Geometry
The geometry of a triathlon bike is one of the more significant things that makes a triathlon bike stand out. It’s not super obvious or sexy, but it is important.
The main different is where the saddle sits in relation to the bottom bracket. This is what your cranks are mounted to. You are positioned further forward on a triathlon bike in the aero position, so you will want your saddle to be further forward..
Triathlon bikes also have a shorter wheelbase, which is the distance between the wheels, than a road bike. This gets you into a better, more comfortable position, but does mean the bike doesn’t go round corners as well. Combine this with deep section wheels and you’re looking at a bike that excels on the flats, but will be left behind on technical downhills.
It is generally a more aggressive setup, but I won’t go into concepts such as seat tube angle and reach here. It is beyond the scope of this article and unlikely to mean much.
How much faster is a triathlon bike?
This is an incredibly difficult question to answer. It depends on the setup, the position, frame and the like. However, ten minutes over a middle distance, and twenty minutes over an Ironman are rough estimates. It’s very much a nice to have, but it still comes down to your performance at the end of the day. I’ve blitzed past bikes worth 20X mine in the past.
Conclusion
Triathlon bikes are high end bits of kit for experienced triathletes. I generally recommend against buying one in your first season of racing to prevent investing a lot of money in something that may end up collecting dust in a year’s time.
If you have money to spend on your triathlon performance, you would be much better off looking into training plans or even coaching. Where a triathlon bike might save you a handful of minutes, I have helped people take hours off of their PBs with my coaching.
