For the sake of this article let's assume you have an good quality carbon fiber road bike such as a Kuota Kharma with SRAM Rival. It's not freaky high end by any means but a good solid bike. You love how it rides but now want to make it faster. Do you need to get a new frame or upgrade your groupo? What about wheels? Will a stiffer crank give you more speed? If I make my bike lighter, how much faster will I be?
While people obsess over weight the best ways to faster are put out more power, reduce rolling drag and reduce wind drag. The three upgrades I recommend cover these areas
Here's the 3 equipment upgrades to make your road bike faster.carbon bike parts
These are non-round rings that have been optimized to match the power curve of your legs. The road version have 5 settings so you can adjust the position of the power stroke. A simple chainring upgrade will yield a power increase of 4-5% and a decrease in fatigue. This is one of my favourite upgrades as you notice it from the first ride. You have just a little more going up hill and it never feels like your are pedaling squares no matter how tired you get.
Most road bikes come with relatively cheap tires. The stock tires have a lower thread count to the casing and denser, slower rolling rubber. Upgrading your tires can make a big difference in both speed and the ride quality of your bike. Now there are a number of high quality clincher tires www.bikeonway.com that roll fast and are pretty puncture resistant. My favourite is the Kenda C2C 700 X 23mm. They are light, roll fast and have good puncture resistance. The best part is they are half the price of comparable tires from other brands.
Most road bikes have pretty heavy wheels that come stock on them. A lot of companies put the Mavic Aksiums which are pretty tough but they weigh a ton. In addition to the weight, most stock wheels aren't very aerodynamic. What a bad combination. Upgrading to a deeper aero wheel set that is also lighter will feel like a totally different bike. For speed the deeper the better up to around 60mm. Beyond that will be good for time trials and triathlons but be harsh riding and poor in cross winds. Rims this deep will almost always be make of carbon fiber. This allows companies to make deep rims are still light. Good options are available from Edge Composites, Zipp and Spinergy. Expect to pay a lot more for a set of carbon fiber wheels but they are lighter for the hill climbs and much more aerodynamic the rest of the time. And on top of it all the deep wheels look cool.
A set of 58 mm deep aero wheels will be a couple minutes faster over 40 km. This will make a difference in both long road races and crits.