The humble road brake caliper has been with us for generations and save for the occasional modest update, it has gone largely unchanged over the years. This stalwart component was introduced back in the days of steel bikes and has continued performing its primary task right through into the carbon era.
As bikes have changed, however, so has the form of the simple rim brake caliper. Carbon fiber manufacturing methods have allowed designers and engineers to create shapes never before imaginable. Some of this is done with strength and ride quality in mind, but more and more, carbon’s amazing adaptability is being utilized to create more aerodynamically efficient bicycles. It is this evolution that has forced changes to rim brakes.
Nowhere is this more evident than in the sport of triathlon. With its well-earned reputation for early adoption of new, ground-breaking technologies, any given triathlon race can serve as a showcase of this aerodynamic evolution. A tour through the transition zone will reveal amazing bikes displaying any number of aerodynamic features and fit options. They are all meant to shave drag from the bike-rider system, helping the racer go faster and more efficiently than their competitors, and certainly faster than they themselves would ride a regular road bike.
Some of these speed-enhancing designs have changed the nature of the seemingly ageless rim brake caliper. In seeking incremental aerodynamic gains, designers started repositioning brakes out of the wind. Finding space for calipers while at the same time seeking to optimize frame and fork shapes necessitated changes to the calipers themselves due to space restrictions, or redesigning the brakes altogether. This was common practice as triathlon bikes continued evolving, and in many instances lead to proprietary calipers made to fit specific frames.
All this was done in the name of gaining additional speed, but in the process something unintentional happened, something arguably counter productive to overall performance. By prioritizing aerodynamic optimization, every effort was made to limit the aerodynamic liability of brakes, and ensuring that they work well or being easy to set up and service was relegated to a lower position on a list of design objectives. The job brakes are meant to do, namely slow and stop a bike safely, was put in jeopardy in the race for more speed.
The emergence of disc brakes in triathlon this year is a game changer and will effectively mark the next tick on the sport’s timeline. The safety and reliability gained by moving to disc brakes should be a no-brainer even for the casual observer, but the advantages go beyond this. While some express reservations over the aerodynamic attributes of disc brake equipped bikes, they actually give designers greater latitude to accomplish their goal of creating more aerodynamic machines.
On no part of the bike is this more true than the wheels. As the aero carbon wheel wars continue amongst manufacturers, the removal of the brake track from the rims circumvents one of the largest obstacles remaining in seeking to aerodynamically optimize rim shapes. It will change the conversation in the next phase of wheel development and will also help provide aerodynamic benefits that erase any added drag incurred by disc rotors and calipers. Preliminary testing already shows parity between current rim and disc systems, and the future improvement in rims will almost undoubtedly tip the balance in favor of discs in the coming years. So as we look to the future of braking systems on triathlon bikes, the trend will soon become evident. Gone is the era of manufacturers spending inordinate amounts of time and money trying to develop aerodynamic brakes that don’t work well. Instead what we’ll see is the move to disc brakes that both work and beg designers to do what they do best– innovate fast bikes.