There are many components such as wheels, suspension, drivetrain and brakes, which are attached to bike frames as per the riding requirements. The wheels contain rim, axle, hub and spokes while drivetrain includes chain, crank arms, derailleurs, gear shifters front chainrings and rear cassette.
The manufacturers incorporate these components on the mountain-bike models as per intended use, targeted riders and price. This is the reason why your mountain bike includes components from different suppliers or brands.
The cheaper mountain bikes will most likely include aluminium frame and cost effective components. The low end mountain bikes are only suitable for occasional use. However, you may also consider for regular use if you are on a tight budget.
The high-end mountain bikes incorporate quality components in terms of improved functionality, durability and light weight. Most likely, you will find best component packages on a carbon frame.
Component Packages
Shimano and SRAM are very reputed component suppliers. Their drivetrains are greatly appreciated. A rough comparison between the component packages of these two suppliers has been presented in the following table.
| Intended Use | Shimano | SRAM |
| Basic model | Acera and Altus | X3 |
| Basic model | Alivio | X4 |
| Entry level for dirt trail riding | Deore | X5 |
| Mid-range level | SLX | X7 |
| High-end enthusiast level | Deore XT | X9 |
| Pro race level | XTR | X0 and XX |
Brakes
The rim brakes have become redundant and even the low-end mountain bikes are equipped with disk brakes.
Disc brakes: The disk brakes include brake pads to grip the rotor plate attached to the wheel hub. The disk brakes can be cable activated or hydraulic. The cable activated disc brakes use manual efforts and adjusting, but hydraulic brakes provide much stronger and progressive force without any considerable finger efforts.
- Advantages: There is no wear and tear of rims due to braking and replacing rotor plates are cost-effective as compared to the rims. The disc brakes provide strong resistance without any finger strain. They are perfect for steep descents and wet terrain.
- Disadvantages: The hydraulic brakes are costly and add to service costs. Inspecting rotor plates and replacing them are difficult.
Rim brakes: Some models of low-end mountain bikes may still use rim brakes. Rim brakes use brake pads that grip the wheel rims.
- Advantages: Rim brakes are very economical and can be easily observed for pad wear and replaced.
- Disadvantages: The rim brake pads wear out the entire rim which may be costly to replace. Rim brakes require lots of finger efforts but don’t provide sufficient braking power as compared to disc brakes. The rim brakes also become ineffective on becoming wet.
Gearing
You can find the number of gears by multiplying the number of front chainrings and rear sprockets. The following table describes the number of gears available on mountain bikes:
| Total Gears | Front Chainrings | Rear Sprockets | Comments |
| 1 | 1 | 1 | Less weight plus mechanical simplicity. |
| 21 | 3 | 7 | Low range of gears seen on Kids’ bikes. |
| 18 | 2 | 9 | Most often found in the aftermarket setups. |
| 20 | 2 | 10 | Common on light, high-end bikes. |
| 24 | 3 | 8 | Entry-level mountain bikes. |
| 27 | 3 | 9 | Common gears found on mountain bikes. |
| 30 | 3 | 10 | The latest high-end bikes. |
After the number of gears, you need to consider the range of gearing. The range from lowest to highest gears may significantly influence your uphill and downhill riding performance. Sufficient range of gearing will ensure your efficient pedaling as you never run out of gears. The range of gears in the 18-speed bike and 27-speed bike may be same but 18-speed will have fewer increments between the lowest and highest gears. You don’t have to be very confused as the higher number of gears also ensures a wider range of gearing.
The single-speed bikes offer the extreme choice in gear, but some mountain riders prefer such bikes because they don’t create mechanical complications or add to weight. However, you should understand that single-speed bikes require very strong leg muscles.
Tip: Don’t get bothered about the gearing arrangements unless you have sufficient experience to determine that particular configuration options to increase your riding performance.
