If you've been paying attention to what various bike brands have been doing over the past few years, you'll have noticed that disc brakes are becoming more and more standard on road bikes, and this isn't just a sudden occurrence.
For road cars, using disc brakes not only improves braking performance but also has many benefits. Rim heat dissipation is no longer an issue with carbon fiber wheelsets. At the same time, without the brake edge, the rim is lighter and the weight of the wheelset is more concentrated in the center, resulting in better performance. In addition, when the wheels yaw, using disc brakes will not affect braking.
Whether you love or hate disc brake roads, they have quietly come to us. Now all major kit brands have launched their own disc brake products, and more and more road bike brands have launched advanced disc brake frames.
Let’s talk about the characteristics of disc brake roads.
1.Braking power. For most riders, whether rim brakes or disc brakes can lock the wheels, the total braking force is sufficient. The main limitation on the braking force output is the tires, not the brake type. But this is only limited to dry road conditions for daily riding. In humid environments, because disc brakes scrape off the water film quickly, there is almost no water on the surface of the disc, and the braking force is still significantly greater than that of rim brakes. Disc brakes can reach the critical point of locking in the middle section, and the critical point will be clearer than that of rim brakes, which will not reach the critical point until the end of the cycle. Therefore, you will feel that using rim brakes to go downhill will make it more tiring to control the brakes.
2.Braking response. Because the braking force is stronger and the response is faster in the initial stage, using disc brakes gives people more confidence when going downhill at high speeds and approaching corners, and also makes control easier. These two factors determine that the braking point of disc brakes can be greatly delayed before cornering, and the average speed in the same corner range can be higher than that of rim brakes.
In addition, an interesting aspect of disc brakes is that the size of the brake disc can be selected according to the user's weight and riding style to adjust the braking force and braking linearity, which is an advantage that rim brakes do not have. In more intense working conditions or when the brakes are pressed for a long time, the brake fluid of disc brakes will boil and produce a large number of bubbles, which will lead to a reduction in braking force output. The thermal attenuation of rim brakes will not be as obvious as that of disc brakes.
3.About weight. This is one of the issues that many riders are most concerned about regarding disc brakes. Currently, disc brakes will always be heavier than rim brakes, that’s undeniable. Simply comparing the current main transmission systems, such as the SHIMANO DUAR ACE R9100 disc brake system, is about 200g heavier than the rim brake system of the same specifications. Also, disc brake wheelsets are heavier because they require hubs that can accommodate the disc and rims that can withstand more torsional loads. Therefore, more spokes are needed and the hub will be heavier. However, due to the elimination of the brake edge of the rim, part of the weight is offset, and many brands have controlled the weight increase to a few tens of grams. On the contrary, many disc brake frames are actually lighter than their rim brake counterparts. For example, the Cervélo R5 is lighter than the rim brake version of the same size by optimizing the carbon stacking and frame structure.
Nowadays, everyone is debating endlessly about disc brake roads. When we look back to about fifteen years ago, various products such as mountain bike frames and wheelsets specifically for disc brakes appeared one after another. Disc brake mountain bikes gradually changed from a novelty to a complete system that ended up being lighter than the equivalent rim brake version.
We can believe that the shortcomings of disc brake roads will gradually be smoothed out, and the advantages will gradually become apparent.