Bike Frames

Whether you’re interested in a “round the town” touring bike for maximum comfort, or are ready for some serious trail riding, there’s a frame for you. And because components are interchangeable on bikes, don’t be afraid of an upgrade.

Jeremy Jensen

5/15/20235 min read

Pretty much everyone has seen a bike rack at a store, whether they're hanging or stacked, often it seems like picking out the “perfect bike” means finding one that you can climb into without tipping over, and has the right “look.” Even without being in the shop, I can smell that awesome rubbery “new bike smell.” It’s such an inviting smell, that brings back memories of childhood and getting my first bike. You might discover the same if you “stop to smell the roses,” next time you’re in! Making memories is part of the fun of the hobby. Upgrading to your first mid-range, or high-end bike can be very exciting, too!

Lots of customers come in, and the first thing they do is find a bike that “fits” their size. This is the right place to start. But even when they find the right size, the prices can be SO different! Almost always, questions arise about what the differences are in the bikes and what makes the prices so varied.

The basic parts and components of the bike are a huge part of the price. The frame is a large part of the price of a bicycle. Take a minute or two to check your understanding of frames, or pick up something new, below.

The Frame:

The basic foundation of the bike and one of the largest component contributors to weight. The size of the frame also largely determines the height of the bicycle, and a proper match to your personal frame (body) is crucial for a best-ride experience. Like clothing, you’ll find frames come in sizes! And like clothing, sometimes the sizes can be confusing. Frames are also made from different materials, each having value to the overall experience, largely through weight reduction. Frames also are configured with fixed rear end or rear shock. While they’re interchangeable, you cannot add rear shocks to a fixed frame. There are seat post suspensions available, but obviously those only work for you, if you’re seated! If you’re interested in upgrading to a frame that has rear suspension, you’ll need to swap out the bike parts on the whole frame. Many customers do this, when they’re ready to upgrade, though depending on the original bicycle, it’s often more economical to upgrade the whole bike.

The Frame Size:

The bicycle frame is measured from the center of the crank axel (where the rotation of the pedals happens), to the top of the seat tube (NOT the top of the seat… just the tube. The seat is the adjustable part.) Mountain bikes are measured in inches, whereas road bikes are measures in centimeters. When trying to determine what size mountain bike to purchase, you can use the guide chart below. It is not recommended to purchase frame sizes larger than suggested, simply because of the distance increase between your foot and the pedal, but it’s quite common for mountain biking enthusiasts to drop DOWN a size to save weight, and they just raise their seat post to compensate. Check your height against your own bike, with the Mountain bike size recommendation below. Note: road bikes have different measurements in cm and their frames are often measured against the inside leg distance, do not use the following chart for road bike frame sizing.

Frame Materials:

The frame materials are varied from the most common, chromoly steel (steel alloyed with molybdenum for strength), to aluminum and carbon fiber. The chromoly frame is the most common, because it’s the least expensive to produce, is actually quite durable and even has some shock absorbing capabilities. You’ll find chromoly on low to high-end bicycles and most road bikes and fat tire bikes will be made from chromoly steel.

Aluminum typically stands out on a bike rack, because it’s BIG. Large, round (or round flattened), tubes are required to provide the strength necessary to support the cyclist and the other components. Aluminum also has more flex and is more prone to damage. The size compensates for a lot of the flex and helps prevent damage to the frame, but ultimately, it’s a trade-off of durability and rigidity for weight. Aluminum, compared to steel is very light! Next time you’re in the shop and you see and odd-sized tubing construction, lift the cycle up. You might find that it’s oddly light. That’s aluminum. It’s actually pretty impressive the first time you do it! The drawback to aluminum is the lack of flex. aluminum sort of “eats” the impact that adds up to microscopic cracks. Over time those micro-cracks add up and eventually cause failure. This is not a reason to avoid aluminium, it’s just something to be aware of, after years of use, or when buying used frames.

Carbon fiber. When carbon fiber made its major debut in the 1990’s, many of us enthusiasts had the same reaction: “Well… that’s gonna break!” While this may have had some truth, initially, the technology has come a long way. In fact, pound for pound todays’ carbon fiber composite frames, compared to aluminum the strength of the frames, is much higher in both stress and impact tests. Carbon has a dampening effect that really helps it absorb repeated abuse that allows it to spring back into place, which is an advantage over aluminum. Those technology advancements come with a price, however. You’ll often find that while the Carbon fiber composite bikes are the lightest, they’re also the most expensive.

When considering the different materials, you may initially think that chromoly is the way to go. The reality is, though, that there isn’t any frame that is invincible. Catastrophic failure can happen to all of them with the right crash. Which is why sizing is so important. The right sized frame can help you control the bike better, preventing the crash to begin with.

Suspension Frames:

If you have a fixed rear (also known as “hardtail”) bike, the only option to add frame suspension in on the front fork. While it’s “possible” to cut and weld a new tail on a bike, we don’t ever recommend it. Quite the opposite in fact. Just don’t do it! The total engineering for a rear suspension is in the whole frame. Suspensions are often deeply personal.

A suspension frame usually comes in one of two types. Coiled spring and compressed air resistance (and sometimes a mix of both!). There is a swingarm that pivots on the frame, and the shock attaches to both the swingarm and the mainframe through a linkage system.

On one hand, a suspension system (including the rear shock) makes longer rides more comfortable and actually increases the efficiency of the rider on rough terrain (by keeping the tire better connected to the trail, you get improved traction, handling and control).

On the other hand, a rear suspension results in a loss of speed when climbing and riding easy trails. Rigid bike frames don’t lose energy by compressing the suspension, making the ride easier (if less comfortable). When you pedal on a suspension frame, energy is lost into the suspension instead of driving you forward. Depending on the terrain, you might ride faster with a hardtail. Also, a suspension frame is more susceptible to damage in an impact. More moving parts means more can go wrong. Which brings us to the fact there are moving parts! Maintenance is required.

Lastly, there’s the cost. Suspension bikes almost always cost more than their hardtail counterparts.

Don’t let this deter you, though. When you’re ready to take on some serious terrain, a full suspension bike can make your ride so much easier that your effectively last longer on the trail. Sure, there’s trade-offs, but when you’re landing a hard jump and you sort of “cushion” into the landing, you’ll remember why you purchased a full suspension. Like the smells of fresh rubber in bike shop, those memories can last a lifetime.

Whether you’re interested in a “round the town” touring bike for maximum comfort, or are ready for some serious trail riding, there’s a frame for you. And because components are interchangeable on bikes, don’t be afraid of an upgrade. We can even help you make the swap. Visit us online @ or give us a call for anything you may need!