A change in technical components, but not only that. A shift in trend, style, safety, and habits. Rim brakes vs. disc brakes: who wins? It's impossible to say; as always, there are different schools of thought and philosophies. Both types of brakes have advantages and disadvantages, varying performance in specific situations, and differences in maintenance. Let's explore the most important differences, the pros, and the cons.
The truth is not in the middle
All cycling enthusiasts, from the moment they can remember watching their first races on TV, in any era, remember bikes with rim brakes . These are the classic brakes, the ones that have always been fitted to bikes and that we probably all learned about as children. Disc brakes , on the other hand, represented for everyone, including professionals, not only a major technological innovation, but also something that took some getting used to, both visually and in terms of use. But while for some this innovation guarantees greater braking safety, for many the rim brake on racing bikes represents a habit and a guarantee that they don't want to change, considering the disc brake a novelty that they can even do without. Where does the truth lie? Probably, as often happens, somewhere in the middle? In reality, in this case it would be reductive to stop there. In fact, there is significant data demonstrating that perhaps innovation has truly improved the situation for cyclists, both amateurs and professionals. Let's investigate further.
The rim brakes
The brake pads on racing bikes are the parts that work in contact with the rim, pushed by the brake calipers. They are made of a soft, rubbery material that ensures maximum friction. The pads' rubber is extremely dense and must not deteriorate too quickly when subjected to the high temperatures created by kinetic energy during braking. The pads' rubber has grooves that drain water and more easily remove any dirt that may build up. The direction of these grooves is very important for proper installation of the pads. If installed backwards, they won't function as they should and may even come off. This detail already highlights that installing the pads is not a straightforward task, and must be performed by experts. Brakes are not to be trifled with. Therefore, if you have even the slightest doubt about how to proceed when replacing the brake pads on your racing bike, contact a bicycle mechanic who will perform the job professionally. Let's now see how they work in the two main phases, the actuation and the distribution of the braking:
- Braking is actuated by a metal cable that is under tension and therefore subject to loosening over time.
- Braking distribution: the contact point is the braking track of the rim which is “crushed” by the two pads and therefore slows down its travel.
What are the advantages of rim brakes?
- Without a doubt, compared to disc brakes they have a significantly lower purchase and maintenance cost .
- Grams count, especially for professionals, and rim brakes guarantee a much lower weight compared to disc brakes.
- Less inertia, due to the absence of the disc.
- Now, it's even easier to find rim brake- compatible brakes, frames, and wheels .
What are the disadvantages?
- In case of long and frequent braking , as can happen on very steep descents, the pads can overheat and lose modularity and efficiency.
- Similarly, skates may perform less effectively in rain , as the water changes their grip on the rim.
- To brake, the effort required by the cyclist is more intense than that required when using disc brakes.
Disc brakes
It's a fact that more and more professionals are choosing to use disc brakes rather than rim brakes. This revolution is rapidly taking place, yet it still faces many skeptics, but it will most likely be complete and mature within a few years. Significant technical advances are being made, and soon all the difficulties associated with disc brakes may no longer exist. Compared to traditional brakes, how do disc brakes work? Here too, let's analyze the actuation and distribution of braking power.
- Braking actuation : the system consists of the pump (coupled to the lever), the hydraulic circuit, and the caliper. The operating principle consists of pressurizing an incompressible fluid, thus transferring the force applied to the lever to the brake pads.
- Braking distribution : the force applied to the pads compresses the disc attached to the hub, slowing its rotation.
What are the advantages of disc brakes?
- The disc brake offers greater braking power than traditional brakes, allowing for better slowing at high speeds.
- Less force applied to the lever for the same deceleration
- Greater modularity. Braking is more controllable and smooth.
- On wet asphalt they guarantee better grip : disc brakes significantly reduce the risk of losing control and braking is less difficult.
What are the disadvantages?
- Disc brakes are more expensive than traditional ones
- Frame and wheels: You can't upgrade from traditional brakes to disc brakes on an older road bike, as disc brakes require special wheels and frames .
- Weight: As always, this is an important variable that can make a difference for competitive riders. Disc brakes weigh more than rim brakes (although increasingly lighter disc brakes are available).
- Greater inertia, due to the presence of the disc
Speed or difficulty in changing wheels?
We haven't included this detail among either the advantages or disadvantages, as there are still different schools of thought regarding this specific situation: the moment of changing a wheel . This is a circumstance that concerns professionals in particular, since in a race, in the event of a puncture, changing a wheel is often a crucial moment, and saving even a few seconds can make a difference.
Changing a wheel with a disc brake requires great care when inserting the rotor into its seat, and in most cases, especially during races, this operation is not trivial. In recent years, more and more professional teams have been replacing their bikes directly in the event of a puncture, thus avoiding this problem.
In favor of the disc, however, it should be noted that this configuration always comes with a thru-axle attachment system, rather than the classic quick-release system (used with rim brakes). The wheel is secured to the frame by screwing directly onto an axle, which for racing bikes is 12 mm in diameter, greatly simplifying removal and attachment.
Another very important aspect of this configuration is that the introduction of this thru-axle system has brought a significant increase in stiffness with a significantly reduced weight. This stiffness gives the rider an ever-increasing feeling when braking, benefiting performance and safety.
Conclusion
As always, we're not here to provide definitive answers (because there aren't any), but to discuss them with you. There's no denying that disc brakes are the future, and for many, they're already the present, especially in the professional world. In a field where performance is everything, it's obvious that the safest and most effective solution is the one to choose. However, it's fair to assume that rim brakes will never disappear. A world of amateur and competitive cyclists will continue to prefer traditional brakes for various reasons, such as cost, maintenance, or even simple habit. Therefore, the two types of brakes will most likely coexist over time, engaging in healthy competition, just like two riders in a race.
