design

Whether a mountain bike is comfortable, light and easy to handle, how high strength it can withstand, how long it can be used and whether it can be upgraded depends on the frame.

Frames can be roughly divided into two types: hard frames and full shock-proof frames.

Hard frame: it is more labor-saving, lighter and cheaper to ride, and a frame of about 500 is good.

Full-shock-proof frame: It is more comfortable, and you don't need to slow down on bumpy mountain roads, but it is slack to ride, not suitable for long distance, and the price is higher, especially the excellent rear shock-proof, which is equivalent to the price of the frame.

front fork

The front fork is a high-tech component in mountain bikes, and mountain bikes with hard front forks are rare. Now they are basically front forks with shock absorbers.

Media type of front fork:

(1) Spring fork: the lowest fork without damping.

Features: Cheap, 300 yuan can buy a good one.

⑵ Resistive glue: Resistive glue is used as the medium without damping.

Features: Supply exceeds demand, but the resistance glue will age in about three years and needs to be replaced.

(3) Oil spring fork: spring is used as rebound medium and oil is used as damping.

Features: heaviest, but strongest. Springs are relatively wet to use and sensitive to small vibrations. General shock absorber oil is changed once every six months. How to remove the fork and change the oil?

(4) Oil-gas fork: air as rebound medium and impact oil as damping.

Features: lighter than oil spring fork, but less firm. It's not that low, ordinary cross-country is enough. ) once every six months, the garage will provide a special pump for free, or you can buy it separately, and the barometer will be around 200 yuan. The advantage of using air as a medium is that it is lighter and can protect the rider's wrist in high-speed off-road, but it is not sensitive to small vibrations.

The working sequence of the front fork should be: when encountering an obstacle-the front fork is compressed-compressed to the extreme-bounced back to its original length (the rebound speed is affected by damping)-the work of the bouncing system is over.

braking system

The braking system includes a brake, a brake handle and a brake pipeline.

There are two kinds of brakes for mountain bikes: [V brake] and [disc brake].

V-brake: Very powerful, because it is a friction wheel brake, so the wheel must be adjusted in place, and it is not easy to deform.

Disc brake: Compared with V brake, it is more difficult to lock the tire. When driving at high speed, locking is very dangerous and will lead to sideslip. Disc brakes are very expensive, and the better one is around 1000 yuan, so a V brake can be bought quite well for 400 yuan.

There are two kinds of disc brakes: hydraulic disc brakes and cable disc brakes. Hydraulic disc brakes rely on hydraulic brake pads to obtain huge braking force, which is very common in downhill vehicles. Cable disc brakes rely on the power of fingers to brake, which is actually more than enough for XC.

transfer system

The transmission system includes a toothed disc, a central shaft, a chain and a flywheel.

Tooth plate: third gear, you know, FSA's is good, more than 100 yuan cheaper to buy a TV, or lightning tooth plate, dozens of dollars.

Central axis: there are two kinds of central axis of plum blossom hole and central axis of square hole, which are different in length and must be selected according to the tooth plate of plum blossom hole or square hole.

Chain: This is a consumable. Frequent chain breaks. If you ride a long distance, be sure to bring a spare one to avoid hitchhiking on the Sichuan-Tibet road.

Flywheel: I have to choose this one. There are 8 flying at 24 speed and 9 flying at 27 speed. For a long time, people have a misunderstanding that the more files there are, the more they will be used. In fact, drivers don't use all gears, and only use one gear 80% of the time, but this gear must be the most suitable for the driver's pedaling strength and frequency. It can be seen that the more gears in the transmission system, the more accurate the driver will be when choosing the gear that suits him. The 27-speed one has three more gears than the 24-speed one, giving the driver more choices.

Variable speed system

The speed change system includes a speed change finger dial, a forward dial, a backward dial and a speed change line.

transmit

Fingering: there are two kinds, one is scissors drive, the other is crank drive, which comes quickly when shifting gears. Some people like scissors to spread, which varies from person to person.

There is also a conjoined manual change, which combines the fingerboard and the brake handle into one. The advantage of this is high compatibility and beautiful appearance, but the disadvantage is that in case the handle is broken and the fingerboard is not broken, they must be replaced together.

Forward dial: go to XT if you have more money, and alivio if you have less money.

Back dialing: I think it is more important than front dialing. It is recommended to install a guy one grade higher than the front dial.

Speed change line: same as brake line.

wheel

Wheels include rims, steel wires, front and rear axles, outer tires and inner tubes.

Rim: The rim should be used for mountain bikes. Because the double-layer ring is stronger than the single-layer ring, it can withstand the test of bicycle performance in bad terrain. Rim is divided into cutter ring and I-ring.

The advantage of the cutter ring is that it has strong longitudinal impact resistance, even if the strength is great, it will not deform circumferentially, but the transverse deformation is well adjusted; Knife ring can also reduce air resistance, suitable for amateur drivers and training. The disadvantage is that it is heavy and not suitable for climbing.

I-ring has stronger lateral impact resistance.

Steel wire: there are two kinds, one is common and the cross section is round; The other cross section is flat, which can reduce the wind resistance of the front.

Axle: also known as flower drum. Friends who use disc brakes should choose the disc brake shaft, because the disc brake piece is fixed on the disc brake shaft; Friends who use V brakes can use ordinary shafts. If they want to upgrade to the disc brake in the future, they can install the disc brake shaft first.

Tyre: Very important, because it directly affects the rider's handling of the car on a specific road. Different tread patterns adapt to different roads.

The flatter the tread, the smaller the resistance, the faster the speed and the stronger the friction on the flat ground. Bald tires are suitable for smooth cement roads in cities. The more convex the tread, the greater the resistance, the slower the speed and the greater the friction on the mountain.

Inner tube: it belongs to consumables.

Frame size

When buying a fitness bike, the first thing to pay attention to is whether the size of the frame is suitable for the rider's figure. The measurement of the frame size is generally based on the length of the vertical tube of the frame. The longer the vertical tube, the longer the frame body. You can also sit on the cushion, put your feet down on the pedal 1, and let your calves droop and straighten naturally, so that your feet can have enough space to stretch when you step on them. The frame size of general road vehicles, the mass production frame brand is one size every two centimeters, and the advanced manual frame brand is one size every one centimeter. From the central axis of the toothed plate to the center of the vertical pipe joint of the upper pipe, it can be gradually increased from the minimum of 47 cm to the size of 62 cm ***8 or 16. We can use:

Span × 0.65 = length of vertical plate of frame.

The above formula is used to choose the size of the road frame suitable for your height.

As far as mountain climbing off-road vehicle is concerned, it is based on the axis of the (big toothed disc) to the center of the upper pipe joint, and takes one dimension every two inches as the size interval of the frame, which can be gradually increased from 14 inch to 22 inches. Because of the large size spacing of mountain-climbing off-road vehicles, it is impossible to calculate the frame size suitable for riders through accurate formula calculation, so we can only choose a roughly suitable frame from the height to ride. Taiwan Province Province is usually dominated by 14, 16 and 18 inches, which is suitable for riders. 155cm is about14cm, and16cm is155-170cm.

Dimensions of faucet handle

When choosing a bicycle, we should not only pay attention to whether the frame size is suitable for cutting, but also pay attention to the size of the faucet and handle. Generally, the length of the faucet is measured with the upper arm and the lower arm at 90 degrees, and the elbow is pressed against the front edge of the cushion (the cushion rod should be adjusted to the center of the cushion). At this time, the distance from the tip of the middle finger to the rear edge of the handle should be three fingers to three and a half fingers. If the size of the frame is suitable for cutting, the length of the faucet used for the overall length is mostly 1 1 to 13 cm (one size per cm).

For road vehicles, the choice of handle width is to hold the handle against the shoulder, and both ends of the handle should be located in the center of the arm at the joint of the upper arm and the shoulder. The size of the handle is generally 42 ~ 45cm (one size per cm) at the outer edge of the handle. If the measured suitable size is 42 cm, it is suggested to use a handle with a size of 43 cm, which can increase the strength of standing and swinging when sprinting on the flat ground or uphill, and at the same time give consideration to the low wind resistance characteristics of posture. In order to improve the handling performance of mountain climbing off-road vehicles, the handle width is much wider than that of road vehicles. The width is mainly 56 cm and 58 cm, and the handle used in downhill race is above 63 cm.

Use and recommendation of mountain bike

Buying a bike is like buying clothes. It should meet the needs of body and occasion functions. To engage in cycling, you must first buy a bicycle that is enough for you to exercise. The so-called exercise here means that the speed and distance of cycling constitute the conditions for exercise. Therefore, the sports bike should be fast-riding, not too heavy, the precision and durability of fast-riding parts should not be too bad, and the transmission lubricity of rigid parts of fast-riding power frame must also be at a high level. With a labor-saving and fast-running bicycle, the relative riding distance will definitely be farther. Judging from the above requirements for sports bicycles, it is no wonder that a good sports or competitive bicycle will bid tens of thousands or even hundreds of thousands.

Generally speaking, it is 1, mainly commuting, 2, weekend sports cycling, 3, long-distance travel cycling, 4, real fever.