This post compares the advantages and disadvantages of disc and roller bicycle brakes in relation to one another.
Definitions
Disc Brakes – hydraulic or cable-operated calipers (jaws in simpler terms) that grab a rotor attached to the hub to slow the wheel.
Roller brakes – an enclosed braking system with rotating elements called “rollers”. When the brake is triggered, a roller presses a brake shoe against a drum. The friction between the brake shoe and the drum prevents the normal rotation of the hub and the wheel slows down.
The Advantages of Disc Brakes
- Supreme Braking Power
Currently, disc brakes offer the greatest stopping power. When maximum performance is the goal, a quality set of disc brakes is the recommended choice.
That said, there are also low-end disc brakes that do not perform as well as one might anticipate. Nonetheless, even basic models are not inferior to roller brakes.
- Lighter Weight
Disc brakes are smaller overall and thus tend to be lighter too. One is highly unlikely to see a roller brake on a bike that’s supposed to be as light as possible. (Note: Disc brakes are lighter but not as light as rim brakes.)
- High Availability
Disc brakes are significantly more popular than roller brakes. Truth be told, most recreational cyclists do not even know that roller brakes exist.
The higher demand, the satisfying performance as well as the availability of both mechanical and hydraulic disc brakes result in a fully saturated market allowing the user to choose between multiple models.
- Cable and Hydraulic Operated
There are mechanical (cable-operated) and hydraulic disc brakes. Mechanical disc brakes are cheaper and simpler to maintain but require more physical effort to brake. Meanwhile, hydraulic disc brakes allow one-finger braking and have the potential to produce more power.
In contrast, most roller brakes are cable-operated.
- Aesthetically-pleasing
It’s a subjective point, but many people find disc brakes more aesthetically-pleasing, especially when installed on a sports bike. One of the reasons for that is that disc brakes make bicycles look like motorcycles.
The Downsides of Disc Brakes
- Exposed to Contamination
The brake pads and the rotors of disc brakes are exposed and therefore potential subjects to contamination. When the upper layers of the pads are contaminated, the braking performance deteriorates.
Another side effect would be squeaking in wet conditions. Sometimes the noise may get so loud that pedestrians mistake it for a bike horn.
In different, roller brakes have an enclosure and are therefore a lot less affected by the conditions outside.
The Advantages of Roller Brakes
- An Enclosed system
The main advantage of roller brakes is that the braking mechanism is hidden and is, therefore, less susceptible to the effect of the elements.
Hence why roller brakes are reserved primarily for commuters and public bikes that remain locked outside throughout most of their exploitation cycle.
The Downsides of Roller Brakes
- Poor Heat Dissipation
Roller brakes are known to have poor heat dissipation. This is problematic when covering a demanding downhill terrain because the brakes could “burn out” and suffer damage and lowered braking power.
- Poor Modulation
The term modulation describes the control that the rider has over the braking force. If a brake has too much modulation, it takes a lot of time/travel to reach full stopping power. If a brake has too little modulation, the brake goes from slightly slowing the wheel to complete lockout very quickly.
Roller brakes often present the second scenario. This is another reason why they aren’t installed on performance-oriented bikes.
- Extra Weight
Roller brakes tend to be heavier than disc brakes. If the user is trying to minimize the weight of their machine, roller brakes would be adding unnecessary weight without providing significant advantages to the bike.
- Hub Limitations
In short, the hubs that support disc brakes are far more than those made for roller brakes. This is a significant limitation.
- Lack of Spare Parts
Roller brakes are far from popular and most bike shops neither sell them nor offer spare parts.
Consequently, the user may have a hard time buying roller brakes and maintaining them over the years. Of course, the Internet allows the acquisition of rare components, but the process is fairly slow. If the unit is coming from overseas, it may be necessary to wait more than a month to receive it.
Another problem that this property arises is the difficulty to repair the brake when touring. Meanwhile, disc and rim brakes are very popular and easier to replace or re-build even when cycling to rare destinations.
- Lack of Education
The low popularity of roller brakes results in little knowledge about them. As a result, the user may fail to find a competent mechanic to fix the brakes. Of course, the rider may educate themselves through the Internet to perform the needed maintenance. However, not every rider wants to be a mechanic too.
Who Are Roller Brakes For?
Roller brakes shine only when used on city bikes/commuters that don’t have to cover extensive downhill sections requiring frequent and intensive braking.
However, if maximal performance (braking power and consistency) is the goal, then roller brakes are a suboptimal choice when compared to a quality set of disc brakes.
Roller brakes can be seen as an inferior solution for touring too due to their uniqueness and inability to repair them and/or find spare parts at remote destinations.
In short, roller brakes make sense only when used for basic cycling.
Who Are Disc Brakes For?
Disc brakes are for every rider who wants maximum braking power and adequate modulation.
