First , on type of disc brake :

Sports bicycle disc brake, mainly divided into two types, one is the line pull disc brake (mechanical), one is the oil pressure disc brake.

1. Wire pull disc brake, relying on the tension of the brake line to let the brake pads in the calipers (to make pieces) friction clamp disc, brake effect;

2. Oil pressure disc brake, with oil as the medium, through the action of the brake force acting inside the piston compression oil, pressure  the tubing through the caliper, so as to promote the piston in the caliper, drive the brake pad clamp disc.

Hydraulic disc brake

The main difference between the two kinds of disc brake lies in the transmission medium. Line pull disc brake through the tension of the brake line, to the disc brake;

Hydraulic disc brake applies pressure to the brake oil in the tubing, which pushes the brake pad to brake the disc. Therefore, the line pull disc brake we usually use the most common 'V 'brake principle similar. Except for disc brake pad, the rest of the two things are basically common. The oil pressure brake is different, the oil pressure disc brake, oil pipe caliper is a complete set of products.

Second , Performance evaluation for both Line pull disc brake and hydraulic disc brake :

1. Line pull disc brake, because its brake power is transferred by the brake line, so can not avoid the same weakness 'V 'brake: because of the length of the line itself, elasticity,shell friction other factors,the loss of braking force, resulting in insufficient braking phenomenon. The above shortcomings can be solved by replacing the brake line maintaining the wetness of the brake line in the tube. (For details, please refer to the original wind resistance paste - "V" brake brake does not work?)

2. Oil pressure disc brake, the brake system uses transmission material for oil objects, (generally common use of DOT standard oil, mineral oil. Dot-3DOT-4 is a special brake oil for engine car disc brakes. The ingredient is to overcome the characteristics of thermal expansion cold contraction, but this substance is toxic, corrosive, can dissolve paint, the advantage is that it will absorb water. Mineral oil its ingredients are very pure, although non-toxic, but also does not absorb moisture, can not wash paint. Advantage is used for a long time endure high temperature, braking force will not be reduced. Because in the use of oily objects in the process of transmission, the first thing to ensure is the sealing properties, so the hydraulic disc brake in the transmission process will be the smallest loss of power. 

At the same time, compared with the line tube, the friction generated by the oil object in the process of transmission in the pipeline is smaller than that of the brake line in-tube transmission, so as to more effectively reduce the loss of kinetic energy enhance the braking force. The performance comparison between the two is the biggest difference because of the different transmission materials the different braking effects. Wire pull disc brake due to a variety of factors caused by the loss of strength resulting in the loss of brake performance attenuation, hydraulic disc brake because of its in the transmission of the smallest loss of power increase the braking performance, at the same time the reduction of friction also provides a good feel for braking (with very easy to achieve great braking effect). 26 inches is 26 inches in diameter. One inch is 25.4 millimeters. 26 x 2.54=66 cm. 24 inch inch is inches, 1 inch is 2.54 cm, 24 inch is 60.96 cm, so the diameter of the wheel is 60.96 cm,the circumference is 191.4144 cm

Third , Performance evaluation for V brake and disc brake

1. Advantages disadvantages of 'V 'brake:

A. Simple structure, convenient maintenance, light weight

B. Easy to lose the braking force issued by fingers, especially in the case of bad external environment (such as rain)

C. Braking time should not be too long, only suitable for low intensity use. (for example: the V brake block is easily burnt when the brake is used for a long time downhill)

Practical application effect:

now on, V brake is still relatively popular, but V brake is best only used for low intensity cycling. Such as urban recreational riding,road racing. This will ensure that you have adequate brakes,will also reduce the weight of the bike, making it more fun to ride. If you are a mountain enthusiast, it is inevitable that you will choose some rough roads rough environments to experience the fun of mountain off-road. But on these complicated roads, the weakness of the V-brake naturally leaks out. Such as the use of brakes for a long time, resulting in the brake block burnt because of its brake failure; The brakes fail due to mud water on the rim of the car on a rainy day, etc......

2. Advantages disadvantages of disc brake:

A. It is inevitably heavy in weight difficult to maintain due to its complex structure

B. Afraid of oil pollution, afraid of collision to the disc

C. Strong, better adapt to the harsh environment

Practical application effect:

After installing the disc brake, it will inevitably be heavier than the V brake. But you sacrifice weight get enough brake protection. Disc brake almost no environmental requirements, the only need to pay attention to is the care of the disc. Make sure you don't get oil stains on your discs,make sure the shape of your discs doesn't change. The muddy V-brake is the basic brake failure

Some suggestions:

In general, there are advantages disadvantages between V brake disc brake. A good V brake will not be cheaper than disc brake, colleague V brake with its light weight advantage in many cases have to mention. Disc brake with its brake performance advantage, also gradually to occupy the market. Can not be as some people say that V brake is not good, disc brake is not so unilateral affirmation. It is suggested that you choose the right brake according to your actual needs. Between the line pull disc brake oil pressure disc brake, if the economy allows, I still recommend you to choose oil disc. First of all, there is almost no big difference between the performance of ordinary line pull disc brake V brake (except high-end line disc), so if we just to look good, then it is better to use the money to buy a good V brake to ensure your driving safety. 

The same price under the line pull disc brake oil pressure disc brake between the performance will be slightly superior to oil pressure disc brake. It should also be noted that many motorists think the oil dish is difficult to maintain, which is wrong. After you buy oil dish commonly, most dealers will be responsible for installation, so installation need not worry about. After installation, after the general use of about 100 kilometers,then the dealer is responsible for giving you a simple debugging (exhaust air, correct the clamp so on). In this way, your oil disc after a run in period, you enjoy to 'abuse' your brake, he will never let you down, under normal circumstances will not bring you brake ineffective, rubbing disc other annoying phenomenon.