One of the advantages of exercise bikes over other forms of cardio, such as running, is that you can vary the level of resistance. This allows you to increase the intensity of your workout without changing the duration or length.
Resistance is also how an exercise bike simulates the feel of outdoor biking. Increasing the resistance imitates going up a hill, while turning it down allows for a less intense workout. Many people also like varying the resistance for interval training.
But did you know there are several different forms of resistance - and each has advantages and disadvantages? The type of resistance is one of the most important considerations when choosing an exercise bike, so it's important to know which is best for your requirements.
In this article, we'll go through the most common types of resistance - frictional, magnetic and air. By the end of the page, you should have a much better idea about the advantages and drawbacks of each type.
Types of Exercise Bike Resistance
There are two categories or exercise bike - those with a flywheel and those without. The majority of bikes have a flywheel and use either friction or magnets to produce resistance. Air bikes don't have a wheel, and instead generate resistance using a fan - but we'll get to those later in the article.
If the resistance of a bike was limited to the weight of a flywheel, the only way to increase it would be heavier flywheels. This is unpractical and also wouldn't allow variation in resistance. For this reason, exercise bike manufacturers have come up with various ways to vary resistance without changing the flywheel.
The most common form of resistance is frictional. This type uses a pad in contact with the flywheel to increase or decrease resistance. The pad can either be located on top of the flywheel or either side (in a similar way to a caliper brake system), and resistance is varied using a tension knob.
A benefit of frictional resistance is that it's cheap to manufacture. This leads to lower prices compared to magnetic resistance. Frictional resistance also stays the same regardless of how fast you're pedalling, so you can have a consistent workout.
There are some drawbacks though. Frictional bikes make noise when in use, due to the contact between the pad and flywheel. If a bike is functioning correctly, this shouldn't be too loud, but it's certainly noticeable. If the wheel isn't properly lubricated, frictional bikes can start to squeak.
Another downside is that frictional bikes require more maintenance. The wool pads wear out after around 9-12 months, depending on how much you use the bike, and need to be replaced. The pads also need to be lubricated.
Another common form of resistance is magnetic. Instead of using friction, two magnets are placed either side of the flywheel. This causes a resistance that varies depending on how close the magnets are to the wheel. Some bikes have a knob to adjust the resistance, while others allow the magnets to be moved via the on-board console.
One advantage of magnetic resistance is that the magnets never contact the flywheel. This means resistance is created silently, so you don't get the "shoosh" sound associated with a frictional bike. The lack of contact also reduces the need for maintenance, as there's no pads to replace or lubricant to re-apply.
A downside is that the resistance can increase as you pedal faster. This is due to the way the magnetic fields generate a resistance. If you want a continuous resistance level regardless of RPM, then a frictional bike might be the best option.
Bikes that use air resistance have a completely different design to magnetic or frictional. In fact, these bikes don't have a flywheel at all. They use air-resistance, caused by a large fan-type wheel, to increase the difficulty of a workout. The faster you pedal, the more resistance the bike provides. Many also comes with movable handles, much like a cross trainer, to get your upper body working too.
As you can see from the image to the right, air resistance bikes have a "penny farthing"-style appearance due to the large fan. They provide a completely different feel to magnetic or frictional, as you can't alter the resistance directly. A bonus is that they generate a cooling breeze which can be pleasant during a tough workout!
But what are the real advantages of a fan-resistance exercise bike? The first is the cost. As they don't require anything more than a fan, air bikes tend to be at the lower end of the price spectrum. The lack of magnets or frictional pads also means they don't require much maintenance.
Air resistance exercise bikes can also provide a gruelling workout. Fighting against increasing resistance as you speed up can be extremely tiring, so if you want a hard workout an air bike is a great choice.
There are some downsides though. Air resistance bikes are loud when you pedal fast. If you enjoy watching TV while working out, you might need to use headphones when at a higher RPM. They also don't provide as much versatility in workout type as other bikes, as the resistance is entirely dependent on how fast you pedal.
Which Should You Choose?
The first decision is whether to buy an air resistance bike or not. If you want a bike that will push you to your max and doesn't require much maintenance, an air bike might be a good choice. They are also relatively cheap considering the excellent workout they provide.
For most people, a bike with a flywheel is the best choice though. Magnetic bikes have a number of advantages, including quieter operation, less maintenance and a smoother ride. Frictional bikes, on the other hand, are cheaper and able to provide a constant resistance.
If you're on a tight budget, a frictional bike can still be a great investment - and you'll get a better all-round bike than if you pay extra for magnetic resistance. If you can afford a magnetic resistance bike, however, you won't regret your decision.
For more information about choosing a bike, check out our best exercise bike page.