Our cycling & indoor training jargon glossary

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Sometimes there's no way around technical jargon when talking about the advantages and differences between our various indoor training possibilities. So we figured we'd put all the weird words in one place for your reference.

Think we missed something? Let us know.

Resistance Units

A resistance unit on an indoor bicycle trainer is the physical unit on the trainer that generates the resistance against which the rider works.

In the most basic sense, bike trainers are made of two elements: a physical aspect and a mathematical one. When it comes to your physical ride, that is where the resistance unit comes into play.

Here at CycleOps, each type of resistance unit uses a different method to create that real-ride feel. The resistance unit also acts as your trainer's "motor," so to speak, and can be removed from the frame for servicing or an upgrade — if you so wish.

CycleOps Magnus resistance unit

Not every trainer offers the same type of resistance or real-road feel. Here's a brief overview to help you make your pick.

  • Wind trainers are based on the simple concept that the faster you pedal, the more resistance you create in the fan-like flywheel — in other words, the resistance is progressive. Keep in mind that noise level also rises in relation to your speed.

  • Magnetic trainers offer five adjustable levels of linear resistance, which you can control from a handlebar-mounted shifter. Magnets inside the flywheel ensure that your ride stays smooth and even throughout your workout.

  • Progressive Magnetic trainers are also designed for smooth rides. However, the difference is that as you increase your pedal speed, the resistance increases exponentially. Simply shift gears the same as you would outside.

  • Fluid trainers are PowerTuned to provide smooth, realistic accelerations and inertia for an extremely realistic road feel. Fluid resistance units are also exceptionally quiet at every speed.

  • Electronic trainers are equipped with PowerTap technology, giving you precise measurement and feedback. This means you can create customizable workouts and have precise control over your training zones and slope. The controlled resistance is best when paired with VirtualTraining.

  • Electromagnetic trainers use resistance that is created by running an electrical current through a series of windings around a magnetic core. This results in precise and rapid control of the trainer's resistance, making the experience more realistic than permanent magnets used in non-electronic trainers.

Resistance Curves

Resistance curves generate the math part of your indoor bicycle trainer experience. Using factors like wheel speed, PowerTuned technology, and cadence rate, they all work together with one of the five types of resistance units above to bring a realistic ride indoors.

Not all bike trainers create resistance the same way. Here's a brief breakdown to help you choose which will work best for you.

  • Linear resistance means that when you pedal faster or shift gears on your bike, the resistance changes proportionately to your change in speed. This type of resistance feels least like riding outside.

  • Adjustable resistance allows you to choose from various levels of linear resistance on the trainer.

  • Progressive resistance is much more "true to the road" because when you pedal faster or shift gears, the resistance increases just as it would out on the road.

  • Controlled resistance offers you the ability to predefine workouts with varying degrees of resistance that are managed by a compatible head unit (like the PowerTap Joule GPS), the CycleOps VirtualTraining app, or other compatible apps. The trainer then adjusts as you pedal.

Learn even more on our CycleOps Science: Resistance Curves page.

Fluid Trainer Resistance Curve

SuperMagneto Trainer Resistance Curve

Fluid Trainer Resistance Curve


A term most often seen in our trainer product descriptions, PowerTuned means that a specific trainer features a resistance curve created using PowerTap's technology to produce the widest range of resistance at real world speeds. Each resistance unit is also tested using a PowerTap to ensure a consistent resistance curve from one to the next.

Wheel Size

Wheel size refers to the size of your bike’s wheel. Finding the wheel size is as simple as its definition, simply check the outer sidewall of your wheel’s tire. Knowing this information helps you know if your bike will be compatible with our indoor trainers.

Learn more about how to find your wheel size.

Clutch Knob

This innovative feature can be found on most of our indoor trainers. It is yellow and functions similar to a gas cap as it clicks until it has reached the perfect tension between your rear wheel and resistance unit roller.

See the clutch knob in action:

Classic Series

Our two series of indoor trainers has everything to do with the frame. The Classic Series is a steel frame design that utilizes a bolt action clamp and leveling feet for a secure ride.

Pro Series

Our Pro Series frames are foldable, come preassembled out of the box, and feature a one-sided leg adjuster so that you can easily ride on any surface.

Trainer Skewer

All of our trainers come with our trainer skewer, and for good reason — it provides the best bike-to-trainer fit.

Using our trainer skewer will also reduce the wear and tear on your road skewer (which is important when you're zooming down a hill at 30 mph) and allows bikes with nuts to be compatible with our full trainer line.

Plus, our trainer skewer is robust enough to stay in your bike year-round – a key time saver for those pre-race warm-up sessions.

View more details about the trainer skewer.

CycleOps trainer skewer

Trainer Tire

A trainer tire is a bicycle tire specifically designed to withstand the unique elements associated with using an indoor bike trainer.

For instance, did you know that riding indoors on a trainer/roller will generate more friction than when riding outdoors? It's true. And most outdoor tires are not designed to handle that amount of excess heat. That's why we make and recommend the use of training specific tires.

Learn more about our trainer tires.

CycleOps trainer tire

Bluetooth Smart

Products that use Bluetooth Smart technology communicate with Bluetooth Smart Ready products, such as the iPhone 4S or higher and on iPad version 3 or higher. To use Android devices you must have the most recent version of OS or Jelly Bean 4.3. Currently, the PowerTap Mobile App is only available for Apple Products. Bluetooth Smart is also integrated on most new Windows 8 PC systems.

Learn more about which products are compatible with Bluetooth Smart.

Bluetooth logo


ANT+ FE-C enabled devices communicate with other devices that contain ANT+ sensors.

Learn more about ANT+ enabled products from PowerTap.

ANT+ FE-C logo


In the cycling world, dual-band technology is defined as products that communicate via Bluetooth Smart and ANT+. Using a product that features dual-band technology allows the athlete to choose which communication protocol that works best for them, their training software of choice and/or accessories of choice.

Learn more about Bluetooth, ANT+ and dual-band protocols from Saris Cycling Group's Chief Electrical Engineer, Ed Watson.