Fluid vs. Magnetic Bike Trainers: A Detailed Comparison

By Robbie Ferri CPT

CPT & Indoor Cycling Instructor

When winter comes around, many of us cyclists struggle to get our training in. With many of us living in places where the weather turns bad, getting your cycling fix in can be difficult. Many of us turn to training indoors, and this might be on a spinning bike, exercise bike, or even a turbo trainer. 

Here at Girl Bike Love, we get asked many questions about indoor trainers. Indoor trainers come in many different types, such as wheel on, direct drive, and some are even made with rolling pins. A question we are often asked is about the difference between fluid and magnetic turbo trainers. In this article, we’re going to be discussing this. 

The Short Answer

Both of these turbo trainers typically come as wheel-on bike trainers. You will insert your bike into them with a special skewer, then tighten it against the roller. What makes these different is the way they work and the experience they produce.

Fluid trainers use fluid to create resistance. They are very quiet and can challenge the rider to a very high level using the bike‘s gears. Then you have magnetic resistance turbo trainers, which use magnetic eddy current to create resistance. It can be controlled to different levels and excellent for a light warm-up all the way to a challenging workout via a controller. 

Different types of Bike Trainer

Bike trainers come in many shapes and sizes and are designed to be used in different ways. When looking for the perfect bike trainer for you, it can be challenging to know what to go for. Before we get into speaking about fluid and magnetic trainers, it’s important to speak about the different types of bike trainers on the market. 

Wheel On Turbo Trainer 

A wheel on turbo trainer is where you put the whole bike on the trainer itself, and the rear tire sits on a roller. The resistance comes from the roller itself and can be controlled by the bike gears or a control switch attached to the handlebars. A wheel on turbo trainer is very quick to set up and cheap to buy. The drawbacks are you do wear down your rear tire, and these kinds of trainers can typically be quite loud. 

Direct Drive Turbo Trainer

Then we have a direct drive turbo trainer. These are trainers where you remove the bike‘s rear wheel, take the cassette, put it onto the turbo trainer, and then attach the bike without the wheel. A direct drive turbo trainer is often referred to as smart turbo trainers as they can connect to applications such as Zwift. These trainers can be fairly expensive and require some time to set up, but you get an amazing experience out of them.

Tip: You can check the detailed comparison of the wheel-on vs. direct drive bike trainers!

Rollers

Rollers are a type of trainer that used to be very popular and still are for certain kinds of cyclists, such as track cyclists. A set of rollers is three small rolling pins where the bike sits on top, and you can ride with the momentum and lean the bike side to side. These are very basic and can be fairly challenging to get used to, and you will probably have seen a few videos of cyclists falling off. 

Comparison Table

Fluid Bike Trainers

Fluid bike trainers are a great way to get fit and come with some amazing advantages compared to other types of trainers. A fluid trainer comes as a wheel on bike trainer and will easily fold away when needing to be stored. It’s easy to put the bike in and remove it. All you generally have to do is change the skewer for a training skewer, and you are ready to go once the bike is on tight in the trainer and the rear wheel is on the roller wheel.

A fluid bike trainer is very unique in the way it works. The rear roller, which spins up against the wheel, is connected to a fan blade, and this is placed in a chamber of fluid. As the fan spins faster, it has to work harder to push through the fluid, causing more resistance. Fluid trainers have one single resistance level, and the more you spin up the roller on the rear, the tougher it gets. This means you can control the resistance with your gearing. 

Fluid trainers are very smooth to use and quiet even under heavy operation. They are fun to use, and even those heavy sprints feel great on the trainer. Fluid turbo trainers can be basic or have smart connectivity and be used on applications like Zwift. 

Fluid trainers do come with some drawbacks. They wear through tires fairly quickly unless you use a turbo trainer tire and wear down other components such as the chain, chainrings, and even the cassette. 

Recommended Trainers

Cycle Inn Fluid Trainer

Cycleinn Fluid Bike Trainer

It works with all different types of wheels from 26” to 700c and can be used with all different braking systems. The max capacity is 265lbs which is high and has a natural road feel, making it feel much more authentic.

Price & Reviews

The Cycle Inn fluid trainer is incredible value for money, coming in at $85. It looks great in a bright blue and comes with a front raiser and turbo trainer skewer, which is a nice touch. It’s very easy to get the bike in and use, and one thing we really liked is the quick-release handle making it even easier than other fluid trainers like this. 

Kinetic by Kurt Smart Fluid Trainer

Kinetic by Kurt Road Machine Smart Bike Trainer

We love that it has smart capabilities and can be used with Zwift and other applications. It’s going to give a silky smooth feel to it, and it also comes with a free monthly subscription to Kinetic fit to get you started. This is one of the quietest fluid trainers on the market and is considered one of the best for ride feel.

Price & Reviews

The Kinetic by Kurt is one of the best smart fluid trainers on the market and one we highly recommend. It comes in a vibrant green and has large wide legs making it a very stable training even when you’re in those sprints. It works with all kinds of bikes but is best with a road bike.

Magnetic Bike Trainers

Magnetic bike trainers are very similar to fluid trainers but come in two different forms. You get magnetic trainers as a wheel on and also direct drive. Today we will be speaking about the wheel on trainers. Like with a fluid trainer, these literally take seconds to get the bike into the turbo trainer, and you will typically only need to change over the skewer. 

A magnetic trainer works differently from a fluid trainer. The first thing to mention is typically, they will come with a controller attached to a long cord like a brake inner and outer. You screw this to the handlebars of your bike. Once the bike is in and the rollers are connected to the rear wheel, you can start pedaling. To create resistance, the bike uses a magnetic eddy current. The closer the magnets get to the bike‘s flywheel, the more resistance that is created. 

The controller is typically on cheaper non-smart models and will give you options of the amount of resistance you add, typically between 6 to 12 levels. On smart models, it can be controlled automatically by an application such as Zwift or Sufferfest. It is nice to have control of the resistance, unlike on a fluid trainer.

Magnetic trainers do come with some drawbacks, like another wheel on trainers they wear through tires and other components on the bikes. Magnetic trainers are typically louder than fluid trainers and don’t give as realistic a feel, but this feeling is something very easy to get used to. They do have a limit to the resistance they can give compared to a fluid trainer.  

Recommended Trainers

Euter Mangetic Trainer

The Euter is an excellent example of a budget magnetic bike trainer. It comes with everything you need to get started and is very easy to set up, regardless of your level of experience as a cyclist. It comes in a variety of different colors, and for less than $100, an absolute bargain to be had.

This trainer comes with a front riser, a quick-release trainer skewer, and a quick-release lever to get the bike out in seconds. It has 6 levels of resistance to choose from, and this will be able to challenge a beginner and a seasoned cyclist. We highly recommend the Euter. It’s a great trainer and comes with everything you need. 

Saris S2 Smart Trainer

The Saris M2 is classed as one of the best wheel on smart trainers currently on the market and has some incredible capabilities. It comes in at $300, so not the cheapest, but with this trainer, you do get the best experience possible from a wheel on bike trainer. It looks incredible with its stealth black design, and as far as trainers go, it is fairly small in size.

The resistance is controlled by applications, and we highly recommend Zwift for a trainer like this. It gives smooth changes and will feel solid in a sprint. It’s the go to choice for many cyclists looking for a high-end wheel on trainer, and we can see why.

Cmparison

So now you know about fluid and magnetic trainers, what are the differences you will need to consider before purchasing the right trainer for you? In this next section, we’re going to run through the differences you’re going to notice. 

Resistance Levels

The biggest difference you will find when it comes to picking between a fluid or magnetic trainer is the way the resistance works. In fluid trainers, you will only have one single level of resistance which, as you speed the rear wheel up, will get more challenging. This is because the quicker fan in the fluid spins, the more resistance the fluid creates. 

Then we have magnetic trainers, which have multiple resistance levels, typically between 6 and 12. This means instead of having to speed up the roller on the rear to create the resistance, you can just pick a level, and the rear roller will tighten up. The magnetic system is better for intervals, but the fluid is great because it can create a near unlimited amount of pressure. 

Resistance Power

Resistance power is the amount the trainer can challenge you. Fluid trainers basically have unlimited resistance. The more the fan in the fluid spins up, the more resistance it creates, and with the right gearing, even the most powerful rider could create a challenging workout for themselves. 

On magnetic trainers, there is a limit to the amount of resistance that can be put on. When you get to the top level of the trainer and the top gear on the bike, you won’t be able to challenge yourself further. This shouldn’t be an issue though unless you are a seasoned professional and your bike gearing is set up very low. 

Feel

When we speak about feel, this is what it’s like to ride a bike on these trainers. A fluid trainer has a much smoother feel to it, and the changes in resistance are very progressive, like how it would feel if you were on a real climb. 

On a magnetic trainer, it does feel less realistic as the changes in resistance are very sharp, and it doesn’t have the smoothest feel to it. The fluid trainer does have a much better feel to it compared to the magnetic, in our opinion. 

Cost

Wheel on trainers, fluid or magnetic, vary from around $50 to $300, and the more you generally spend, the better experience you will get. Fluid trainers are a little bit more money, and this is because they are more challenging for companies to make but are much quieter and smoother to use. 

Noise

Trainers are noisy machines especially wheel on trainers, and many cyclists ask us which is the quieter of these two. Typically we find that fluid trainers are much quieter than magnetic trainers. With many moving parts being encased in a fluid chamber, it does make a huge difference to the vibrations and noise level. 

Which one is for you?

Both a fluid or magnetic trainer are going to be a good investment for your indoor cycling. They both have advantages and disadvantages, but there’s very little in it. The fluid is perfect if you’re looking for a quiet, simple trainer with no resistance control, which you can just use for a warmup or a basic workout.

If you are looking for something that can offer you more structure to control the resistance and do more technical workouts, such as intervals and ramp sessions, you will get more from a magnetic trainer. Either is going to get the legs spinning and the muscles pumping indoors, and that’s the first step of getting fit when the weather is bad.

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