Disc brakes are not new thing to use in road cycling, because they were there for quite a while and proved their role as an efficient braking system. In general, road cyclist use caliper over the disc brakes, because manufacturers were building bikes that way.
Disc brakes are now brought in center of attention when UCI approved their usage in the peloton starting this year, but then after the cycling accident in Paris-Roubaix, they are suspended by the organisation. Regardless of that, what about using them on road bikes in regular cycling? Are they safe enough to avoid injuries? Are bikes with disk brakes any faster? Will bikes be heavier? What about aerodynamics? Is it safer to ride on wet, muddy road?
Check the video below by cycling journalist Oliver Bridgewood about pro riders and their thoughts about using disc instead caliper brakes:
Surprisingly no one was questioning the change in bike performance in terms in weight, or aerodynamics, but they were skeptical about their necessity and safety itself.
Are road bikes with discs brakes any faster?
The question is interesting to the most road racing cyclists who want to get from start to finish as quickly as possible. Unfortunately, there is no unanimous answer, because all opinions are different, including riders and experts.
One of the greatest cyclists of all time, Classic rider and Olympic Time Trial champion Fabian Cancellara, choose to use old ones in his final season and said:
“I don’t think disc brakes make me go faster, or slower. It’s technical and personal decision.”
Founder of Boardman Bikes, Chris Boardman gave his positive review:
“Isolation discs are slightly less aerodynamic than rim brakes, but in my experience, better, more reliable braking instills confidence, allowing you to brake later and less often. The weight penalty is negligible. When you factor in the option for reducing weight giving better acceleration, I’d say your performance is far more likely to improve.”
On another hand aero and racing R&D lead at ‘Specialized’ DR Chris Yu gives other opinion:
“Although disc brakes aren’t always slowest option, from a pure speed and aerodynamic perspective caliper brakes are faster. At zero degrees yaw there isn’t much difference. However, with disc brakes a large portion of the aero drag comes when the rotor is exposed to crosswinds. On a completely flat time trial or a race with little extreme braking, disc brakes are currently slower.”
Safety from Injuries
In terms of ‘safety’ allot of pro cyclist mentioned in video, there are possible injuries disc can make at group falls. This specially applies to sprinters in the last few corners, when they are focused more on pedaling and their rivals. Danger of falling is very high and only a small contact can lead to accident involving more riders. If such thing occurs, besides falling, concussion and scratches, you will also make skin contact with disc, previously heated from braking and get rather nasty burns and cuts.
Also to mention mountain bikers, who use bigger discs and brake a lot often on very hard technical downhills. They fall quite often and injuries from brakes are rare.
But in regular cycling, during casual ride or group training, there is rather small chance of that happening. So for conclusion, discs are almost as safe as caliper brakes.
Caliper brakes, in dry conditions, are almost efficient as disc, but are slightly behind on wet roads. That is because the rim of the wheel is more exposed to the moisture than disc, making impossible to achieve late braking without slipping or sliding. Especially on downhill wet roads, where you have small room for slowing down, disc brakes have upper hand.
Bicycle with disc brakes is slightly heavier, but that small amount of weight will not affect losing any performance. You also will get less rotational weight with caliper brakes, what will give a rider easier pace chances for sprinting or climbing.
But for steady rides more wheel weight is appreciated because it gives you more inertial force, which means less effort in maintaining speed. This is often regulated whit having wider rims, but having disc with skinny ones is not a bad idea, cause it also makes your braking even better, due to lighter rim.
Changes in Aerodynamics
Let us be honest, the first thing that makes the most air resistance is rider himself (riding style and position). Second thing is bike geometry design, which has very small differences in general and depends on manufacturers.
Now imagine how small changes between brake systems will be. Surely anyone can assume from looks that caliper gives less resistance, but it is a tiny amount of difference because of the surface it covers.
It is understandable for certain pro cyclist in disciplines like time trial, to be more selective about aerodynamics, because every second matters to them. But for amateur cyclist to consider caliper to be better than disc just from small amount of weight or resistance over their actual purpose, is nitpicking.
From the regular cyclist point of view, it is optional which braking system to use, because they both behave really well in dry conditions, but for more stable braking in corners or emergency braking in traffic, discs will do their job better. However, caliper brakes have cheaper insole pads and are easier for maintenance.
If the performance is all you want, having lighter bike and maximized aero, it is quite reasonable why are you using caliper brakes…and shave your legs.