What’s the Right Flywheel Weight for My Indoor Bike?

Exercising at home is convenient, saves time, and allows flexibility in scheduling. Unlike the gym, however, you won’t have lots of options in equipment, making it critical you purchase the best spin bike for your goals.

As you weigh your options, the most important specification to consider is the flywheel weight. This can get tricky. While most fitness enthusiasts know the basics in how to use their indoor bikes, many don’t understand the nitty gritty details of the mechanics involved in making them work best for your specific needs.

Today, we’re going to clear up the mysteries. When you’re done reading this article, not only will you know what a flywheel is, but you’ll understand how to compare them to make the smartest spin bike purchasing decision, so let’s dive in!

What is a Spin Bike Flywheel?

There are many methods of storing energy that most of us are familiar with and use in our daily lives. From batteries and compressed air to fat stores in our bodies, all of these examples provide energy when you need it. The flywheel doesn’t typically come to mind when considering energy storage, but that’s precisely what they do.

The core component of the indoor exercise bike, the disc-shaped device typically found at the anterior of the bike stores rotational energy for a plain sailing ride. Your flywheel rotates through a direct connection with the pedals with either a belt or chain drive.

What is Flywheel Weight and Why is It Important in a Spin Bike?

Without a flywheel, your spin bike experience would be choppy, awkward, and even dangerous. It’s the job of the flywheel to ensure every ride is smooth, safe, and efficient. As you examine a flywheel on a spin bike, it’s important to consider the weight, because it plays a dual role in rotational and resistance control.

The flywheel weight is the among the most important considerations as you shop for a new spin bike. Unfortunately, there’s not a single answer as to what is the right weight for a flywheel. Rather, there are variables that must be considered to decide what weight is best for you.

The Physics of the Flywheel  

Going back to the high school physics classroom, we recall energy can be neither created nor destroyed. It can, however, be stored. If you were to double the weight of a flywheel, you’d achieve double the energy at the same speed, so you can see why the weight makes a difference.

Heavy or Light Flywheel- Which is Best?

One man’s trash is another man’s treasure. The same basic concept is true when it comes to a spin bike flywheel. For some people, a heavier flywheel will provide the ideal workout, while others may be better-suited with a lighter one. As you’re shopping, you’ll come across many options, which can range in weight from eight to 50 pounds. Most bikes, however, will land somewhere between 30-44 pounds.

Heavy-Weight Flywheel Spin Bikes for a Road Bike Feel

The more your flywheel weighs, the smoother you can expect your ride to be. Since they provide steady-state power, going heavy not only produces a smoother ride, but it can also be safer. If you enjoy training in intervals that include rounds of hills and mountains, a heavier flywheel will make those uphill emulations feel more realistic as these spin bikes feel more like road bikes than lighter options.

Heavy flywheels aren’t for everyone. This option may not be for you if:

• You lack the lower body strength to initiate motion as heavy flywheels require more power to get going.
• You train at lower rpms as this can result in a jerky ride.
• You’re on a budget as heavy flywheels are often pricier.

If a heavier flywheel sounds like the right option for you, 40-44 pounds is a good range to shoot for. Commercial shoppers can go as high as 50 pounds. The Sole SB900 with its 48-lb flywheel is a top-rated choice I recommend checking out.

Low-Weight Indoor Cycling Bike Flywheel for Low-Impact Training

For folks who suffer with joint issues, a lighter flywheel can be less intense since you’re not putting excessive pressure on them to get pedaling. The caveat, however, is that you’re unable to create the inertia necessary for as smooth of a ride as a heavy flywheel provides. Therefore, if you have joint issues and engage in higher intensity exercise, a mid-weight range is probably going to be a good choice like the Stryde bike with its 30-lb. flywheel.

Lighter flywheels also work the back of the legs, providing an excellent hamstring and glute workout. If your typical lower body strength regimen is lacking in posterior muscle recruitment, a lighter flywheel can provide a good supplement.

Importance of Flywheel Positioning

For heavier flywheels, maximum efficiency is achieved when the flywheel is placed at the front of the bike directly beneath the rider. The trouble with this positioning, however, is that it’s in the direct path of sweat that, over time, leads to untimely wear and tear.

Many spin bikes on the market today place their flywheel at the rear of the machine. If you don’t tend to work up a sweat during your workouts, this wouldn’t be a primary concern. However, if you ride hard, flywheel positioning is important to consider primarily for durability purposes.

Setting Up Your Bike for Best Pedaling Technique

When your bike isn’t properly setup, not only do you risk damaging the machine, but you can also hurt yourself and diminish the efficiency of your workout.

To ensure proper form and good pedaling technique are achieved, there are a few tips to follow when you set up your indoor bike:

• Set the seat at the appropriate height by standing next to it and adjusting to the height of your hip bone.
• Sit on the bike, and extend one leg for bottom stroke measurement. Your leg shouldn’t be completely straight. Shoot for a very slight bend in the knee. If it’s too straight, notch the seat down. If the knee is too bent, move the seat up a level.
• Position the handlebars about a forearm’s distance from your seat.
• If your bike has toe cages, make sure the ball of your foot is positioned directly over the center of the pedal.
• If you’re using clipless pedals, ensure cleats are properly aligned.

My Top Spin Bike Recommendation

I’m a big fan of the Myx II spin bike. Its 41-lb. flywheel produces a smooth, seamless ride, and I love that it provides interactive classes to make fitness interesting. Some of the features the average rider will enjoy include:

• Sony 8-megapixel camera to work with interactive classes
• Option of clip-in shoes or standard toe cages
• Inexpensive monthly subscription
• 350-lb. user weight limit
• Top-rated value

Perfect for the athlete who enjoys mixing it up, the interactive classes come at a fraction of the cost of in-person fitness classes. With thousands of programs to choose from in a variety of categories, it’s easy to target training.

Most users will have no issues interacting with the 21.5-inch touchscreen display, and the three-way adjustable handlebars paired with the adjustable seat allow users to find the most effective positioning for safety and efficiency.

Heavy vs. Light Flywheel: Final Thoughts

Now that you understand the impact of the flywheel on your spin bike, you have a better idea of the size that’ll be right for your needs and budget. To break it down:

Heavier-weight flywheels are a good pick if

• You engage in rigorous training.
• You value a smooth ride.
• You have the ability to exert the power necessary to get the bike going.
• You enjoy the feeling of hills/mountains in the comfort of home.

A lighter flywheel may be the way to go if:

• You have joint issues and struggle to get a heavy flywheel moving.
• You don’t engage in high-intensity training.
• You’re on a limited budget.
• You want a bike that’ll work the glutes and hamstrings over quads.

Remember, for a bike that’ll stand the test of time, keep the perspiration zone in mind. A flywheel located at the front of the bike is more likely to take the brunt of your sweaty workouts. If the bike you have your eye on has a flywheel in the front, make sure you wipe it down after each use.

The flywheel is one of the most important factors to consider as you shop for a spin bike, and, by taking the time to research your purchase, you’re more likely to make the right decision. While we’ve focused this article on a deep-dive in flywheel education, there are other important features to consider.

Before you make your final decision, check out our roundup of the top seven indoor bikes on the market. We assess resistance, support, materials, and technology and teach you how to break everything down relative to your needs.