Are you an aspiring Red Bull-sponsored athlete? Or already an avid mountain biker? Maybe you’re just wondering what makes a mountain bike, a mountain bike? One of the most important things about the sport of mountain biking, next to actual skills and technique, is knowing your bike’s anatomy. So, what exactly are the parts of a mountain bike?
If you’ve answered “yes” to any of the questions above, you’ll love reading this article. Here at The Adventure Junkies, we talk about all things mountain biking. In this particular article, we’ll take apart a mountain bike. We’ll discuss all of its individual parts and tell you about their purpose.
WHAT ARE THE PARTS OF A MOUNTAIN BIKE?
Okay so you’ve bought a new mountain bike, or you’re looking for a new one, and you want to know more about all the parts of a mountain bike. Below, we’ve compiled a comprehensive overview of every single piece that makes up a modern mountain bike. From derailleurs to valves, from brakes to pedals, you can find it all here.
Let’s start with the frame, arguably the most important part of a mountain bike. This is the backbone of your bike, the largest part that joins all other parts together. A good frame is what sets any bike apart, so you’re advised to spend some money on it. Quality frames will last years.
Mountain bike frames are commonly available in two different materials. Aluminum (or an aluminum mix) is the most affordable material. It’s light and strong, making it the most popular frame material. The other one is carbon, which is also light and strong, but has the additional perk of being shock-absorbent. Carbon frames are expensive, but worth splurging on if you have the money.
A frame consists of six basic parts: three tubes, two stays and one fork. The three tubes form the main triangle of your mountain bike’s frame, being the top, down and seat tubes. Together with the seat tube, the seat stay and chain stay make up the rear triangle of the frame. Both stays—note that there are two of each, so four in total—connect at the rear wheel hub.
The front fork is the two-legged part at the front of your frame. This is the part that keeps the front wheel in place.
The two wheels don’t need much explaining. Everyone knows why they’re there. It is interesting, though, to take a closer look at the different parts that make up a bike wheel.
The one part everyone knows is the rubber tire, which comes in a variety of sizes depending on the terrain you’d like to ride your bike on. Tires consist of two parts. The inner tire is filled with pressurized air. The much thicker and stronger outer tire has grooves for better grip.
The tire is connected to the wheel’s rim, which is the outer hoop of the wheel. Just like the frame, the most common material used to make wheel rims is aluminum. Cheaper bikes may have steel rims while high-end mountain bikes have rims made of carbon fiber. The valve of the inner tire, used for blowing up the tire, sticks through a small hole in the rim.
Spokes are attached to the rim with nipples and converge toward to center of the wheel. This center is known as the hub, an important part of the wheel containing the axle and ball bearings.
PEDALS, CRANKS AND BOTTOM BRACKET
The pedals and cranks, when pushed, make the chain spin and the bike move forward. The pedals are attached to the cranks, which are connected to the bottom bracket. The bottom bracket is where the down tube, seat tube and seat stay come together. It contains a spindle and the bearings that allow the cranks and spindle to spin.
Pedals and cranks may also be one of the parts of a mountain bike that are taken for granted. However, there are a few things that you need to consider when buying a new mountain bike.
First of all, there are two types of pedals: flat pedals and clip pedals. Flat pedals (with or without teeth) are the best for beginning mountain bikers. Clip pedals, securing your feet to your pedals, are great if you want more pedaling power. They allow you to both push down with one leg while pulling upward with the other. You can also opt to get pedals that are both—one side flat, the other side with clips.
Even the cranks are worth considering. The shorter the cranks, the less pedaling power you have. On the other hand, short cranks are better if you’re downhill mountain biking and go over lots of obstacles.
CHAIN AND GEARS
The chain and gears make up one of the most important parts of a mountain bike. In fact, good sets of gears are what separate high-end bikes from average ones. The importance of good gear sets can’t be overstated.
A good mountain bike has two sets of gears, one at the front at the cranks, and one at the rear wheel. The front gear set consists of two or three chain wheels and the front derailleur. The derailleur is responsible for shifting the chain from one chain wheel to the next. You’ll use the front gear set less often than the rear gear set, as it consists of the big gears. Each gear shift results in a significant difference in pedaling power.
The rear gear set contains more and smaller chain wheels than the front one. This set is responsible for short and precise shifts in gear. You’ll use it a lot, which also means that it needs to have quality materials. Here, too, the derailleur takes care of the shifting of the chain from one wheel to the other. The rear derailleur is much larger than the front one, hanging down from the center of the rear wheel.
You control both gear sets and derailleurs with the shift levers on your handlebar. Gear cables run from those levers to their respective derailleur, transporting the message of what you’d like them to do.
The bicycle brake system consists of three main components. The handlebar break levers are connected to the brake pads or discs by the brake cables. Let’s talk for a second about the difference between brake pads or discs.
Brake pads are located at the top of both the front and rear wheels, respectively near the front fork and the seat stay. By pulling the brake levers, the pads, one on each side of the wheel, get pushed together. By squeezing the rim of the spinning wheel, they’ll slow it down.
You’ll find brake discs around the hub of your wheels. This modern and highly effective braking system also uses pads to slow down your bike. The difference is that the pads are moved onto the disc as opposed to the rim of the wheel. Ibikeride.com says that disc brakes are good for all types of mountain biking because they offer consistent, effective braking regardless of temperature, rim condition, or trail conditions.
SEAT POST AND SADDLE
The seat post slides into the seat tube and can be moved up or down, depending on your own height. It’s secured by tightening the seat post clamp. The saddle is on top of the seat post. It’s essential that your saddle is comfortable and that it wicks moisture and water.
The handlebar, as its name suggests, is where you place your hands. With this part, which contains the brake and shift levers, you steer the front wheel. There are several different types of handlebars. The most common one for mountain bikes is the flat bar. This is basically a straight bar with very little or no upward or downward curves.
Many modern mountain bikes come with either front or rear suspension, or both. Front suspension is placed in the front fork. Rear suspension is much more intricate and can be in either the stays or the seat tube. Often, mountain bikes with rear suspension have a much more complicated frame.