Comprehensive Guide to Indoor Cycling and Trainers
Everything you need to know about indoor cycling
Indoor cycling has changed dramatically in just a few short years. Gone are the days when riding inside was only for the truly dedicated athlete, or those of us who wanted to keep our legs turning when the weather (or lack of daylight) prevented riding outdoors. Now we have an incredible range of trainer options including state-of-the-art machines like the Stages SB20 Smart Bike and an ever-growing variety of apps that work in tandem with many trainers to enhance the indoor riding experience. In this same short time period indoor studio cycling has also grown in popularity, with better bikes, more sophisticated group class software and greater access to indoor classes no matter where you’re located. Whether you’re looking to step up your training with pro-quality workout features, recreate your outdoor cycling experience right in your garage or get an upbeat, high quality workout with 40 friends at your favorite gym there’s never been a better time to explore the latest options for indoor riding.
What is a Smart Bike?
What is a Smart Trainer?
What is power? And how do smart trainers and smart bikes use power?
What is ERG Mode?
How do Smart Bikes and Smart Trainers Calculate Power?
Fluid, Magnetic and Wind Trainers
What is a Wheel-Off Trainer?
Rollers – the original indoor training tool
Smart Trainers or Smart Bike – Which is best?
The Best Indoor Cycling Apps
For riders looking to replicate the outdoor cycling experience in their own garage, smart bikes like the StagesBike SB20 offer the most realistic and immersive experience for indoor cycling. They require a greater investment than other options but they also offer unsurpassed features and performance. Smart bikes are stand-alone setups that require no additional equipment, unlike smart trainers, magnetic trainers, rollers and wind trainers which all require that you attach them to a functioning bicycle. And like smart trainers, most smart bikes need to be plugged into a power outlet to generate resistance and simulate riding conditions or drive ERG mode workouts.
By their very nature, smart bikes are intended to completely replace (and replicate) the bike that’s normally attached to a trainer, and most designs offer micro-adjustments for saddle height, fore and aft, bar reach and drop as well as standard mounting interfaces for handlebars and saddles so you can easily replicate your preferred fit from your outdoor bike down to the millimeter. Crank length can be adjusted via multiple mounting holes for pedals.
Smart bike drivetrains don’t have mechanical gears like outdoor bikes, but many models including the StagesBike have simulated gearing controlled by the electronic drive motor, with customizable shift buttons in multiple locations.
Since they are designed from the ground up to be dedicated indoor cycling machines, smart bikes are usually much more quiet during use when compared to the standard drivetrain of any trainer-and-bike setup, and most have stout frames to handle the hardest stationary efforts with minimal flex and motion.
What makes a trainer smart? Simply put, a ‘smart’ trainer involves an electronically controlled motor that provides variable resistance. When connected to certain cycling apps, the electronic resistance unit can be controlled simulate real-world riding circumstances. Climbs will get harder, and descents will be easy. You’ll enter your weight and height so that app and smart trainer can best recreate the resistance you’d feel rolling down the road at 20mph. Even drafting behind other riders can be simulated, depending on the app.
Smart trainers have been around since at least the 1990’s, with devices like the original CompuTrainer and many others which were perhaps ahead of their time. Without today’s computing power and graphics, smart phone and tablet apps and high-speed internet, these early smart trainers were very expensive and struggled to provide the seamless, immersive experience available today.
Smart trainers are heavier and more expensive than traditional fluid, wind or magnetically driven trainers, and require a power source to control the electronic motor which makes them a poor choice for travel or use for warm-up before events.
A key component to many premium indoor cycling experiences available today is rider power measurement. What is power? Simply put, it’s the measurement of rider pedaling effort, displayed in watts. This number is factored into how cycling apps electronically control resistance as you’re riding in a virtual environment or performing workouts. For example: when riding a smart bike up a virtual hill, the controlling app will factor rider weight, power output and steepness of the simulated climb to determine what the rider’s virtual speed will be. These variables are constantly changing as the rider may push harder, or the hill may get steeper. This is how smart bikes and smart trainers create a realistic and immersive indoor riding experience.
Since smart bikes and smart trainers offer resistance driven by a computer-controlled electric motor, they create an entirely new way to work out indoors—ERG Mode. When engaged, ERG mode works in conjunction with a .FIT or .GPX workout file to drive the trainer or smart bike resistance unit at a specific wattage target for each workout step. In this scenario the controlling app or device works with the smart trainer or smart bike to dictate rider effort. Regardless of rider pedaling cadence, all you need to do is keep turning the pedals until you’re exhausted or the interval is complete. ERG mode does not make workouts and training easier, but it helps the rider perform a prescribed workout correctly in a precise and controlled manner.
There are a variety of power meters available today and nearly all of them attempt to do the same thing: measure rider pedaling force in an accurate and consistent manner, with the output being a numerical measurement of watts. Most power meters are intended to replace an existing component of a standard bicycle, but smart trainers and smart bikes are not limited to bicycle design and can calculate power differently. Since most smart bikes and smart trainers incorporate a computer controlled electronic motor in their designs, they can calculate rider power output by reading the amount of resistance applied to the flywheel, the speed of the flywheel and some other variables to accurately estimate rider power output to +/- 2%.
In some cases, smart bike designs including the Stages Bike SB20 Smart Bike use the same dual-sided, crank-based strain gauge power meter technology found on outdoor bicycles. This offers several advantages: first it allows the power meter to calculate and display true left-right power balance so the rider can see how smooth they’re pedaling between left leg and right leg, and also by using the same crank-based power technology found on outdoor cycling power meters, the rider power data will be closer and more comparable between indoor and outdoor cycling. For this reason some riders prefer to pair their outdoor bike power meter to their controlling app rather than using smart trainer power calculations.
Before Zwift, Watopia, smart bikes and smart trainers, there were not-so-smart trainers with progressive and in some cases rider-adjustable fluid, magnetic and wind resistance trainers. While less exciting than their smart trainer and smart bike counterparts, these devices will give even the strongest rider a leg-busting workout. Manufacturers design the resistance units to provide a realistic resistance curve intended to closely replicate real-world riding conditions, but there is no compensation for rider size or weight, and has always been challenging to get the sensation of climbing to feel realistic. Of the three, fluid units are most popular as they come closest to a real-world riding sensation and are very quiet. Magnetic resistance units are less expensive and many offer resistance that can be altered by turning a knob or flipping a lever, but they generally have a linear feel, rather than the progressive and more realistic feel of fluid resistance. Wind-based units are much less common now and tend to be noisy, but you will still get all the workout you need and they are the least expensive of all options.
For many years, most rear-wheel trainer designs attached to a bicycle by clamping onto either side of the rear wheel axle, and the resistance unit roller would press into the rear tire. The good thing about these designs is that they don’t require the rider to remove their rear wheel so attaching and removing the bike is a little quicker and easier, but the downside is that the resistance roller has a tendency to increase wear on your rear tire, which can get expensive. Some riders would mitigate this by installing less expensive or already worn-out training tires for their indoor sessions but this can be inconvenient, especially when you want to pull your bike off the trainer and ride outside again.
Newer ‘Wheel-Off’ trainer designs require the rider remove the rear wheel from their bike and install the trainer directly to the rear triangle of the bicycle. Wheel-Off trainers require a cassette to be mounted to the trainer, and installing your bike to a wheel-off trainer can be a messy process as you have to wrap the chain, which is usually dirty, around the cassette.
Compared to previous rear wheel trainer designs which did not require removal of the rear wheel, these wheel-off trainers might seem even less convenient but they eliminate the wear-and-tear on rear tires and provide a more direct connection to the resistance unit and more efficient power transfer. Most smart trainers are wheel-off designs.
Rollers offer simplest, most elegant and most basic interface for riding indoors. Usually consisting of three cylinders, two in the rear and one up front connected by a belt or band, most rollers do not attach to your bike directly in any way. The bike simply sits on top of the cylinders and after a few awkward pedal strokes, the rider and bike balances on top of the rollers aided by the centripetal force of the spinning wheels and rollers. Resistance comes from the effort it takes to keep the cylinders spinning and can vary based on cylinder diameter and weight, but for the most part rollers are not the best option for riders looking for the most, or most realistic, resistance. Riding rollers requires the rider to keep the wheels spinning constantly to avoid falling over and unlike any other trainer design, turning the bars does move the bike from side-to-side on the roller cylinders and it is possible to crash if you are not smooth and stable while riding. For this reason rollers have been considered the best means of indoor cycling for riders looking to improve their pedal stroke. Some designs offer bumpers or parabolic cylinders designed to help riders from accidentally swerving off the cylinders.
Smart trainers and smart bikes will both allow you to explore the roads and race your friends in Zwift, they are not equal in terms of the experience they offer.
Smart trainers tend to cost less, and in general are more compact and easier to store when not in use. And while they are somewhat heavy and awkward, they’re comparatively easy to transport should you wish to take your smart trainer over to a friend’s house for a virtual group ride.
Smart bikes like the Stages Bike SB20 Smart Bike are more expensive than smart trainers however they do offer a number of advantages. First and foremost, a smart bike is a dedicated, stand-alone device which does not require the rider to mount a bicycle to it. No removing the rear wheel, no additional cassette that might not mesh with their outdoor bike drivetrain. A smart bike is ready to ride when you are, and your outdoor bike is ready for your next ride outside rather than being connected to a trainer.
Furthermore, smart bikes like the SB20 are designed from the ground up to endure the abuse of thousands and thousands of indoor riding miles, which saves wear-and-tear on your expensive outdoor bike and drivetrain.
Smart bikes and smart trainers can both be shared between multiple riders in a household. For the smart trainer, you just need to swap one attached bike to the next. For smart bikes, it’s much quicker and easier as you need only swap pedals if necessary, and adjust saddle, crank length setting and handlebar reach and height for the next rider. Advantage: Smart Bike. Last but not least, smart bikes can offer features that even the best outdoor bikes and smart trainers simply cannot match, like silent, maintenance-free belt drives, and in the case of the Stages Bike with Dream Drive, even fully customizable, wide-range virtual drivetrains with up to 50 virtual gears.
Smart bikes and smart trainers are equipped with either ANT+ or BlueTooth connections and are designed to offer the best riding experience when paired with one of the many indoor cycling apps including Zwift, Trainer Road, Rouvy, FulGaz, KinoMap and others. Most work with your smart phone, tablet or laptop to provide an immersive on-screen visual riding experience, ranging from cartoon-like realms loosely based on reality to near-exact replicas of iconic roads from all over the world, and these apps connect to smart trainers and smart bikes to control resistance during your ride to simulate the climbs, descents, drafting and other outdoor riding conditions you’re seeing on screen. Most apps offer training and workouts, group rides and racing, and the opportunity to socialize with other virtual users, and most charge a monthly membership fee, though some do offer a basic free version and a premium version. Nearly all offer a free trial so you can find the one that best suits your needs.