A lady exercises with the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike

Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike Review

The Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike is a magnetic and belt-driven unit that is designed to offer cardiovascular workouts at home. It engages the arm, the core, and the lower body muscle groups while the user loses calories that ultimately resulting in weight loss.  

It has an LCD monitor that tracks workout progress that includes the heart rate, and there are 2 dumbbell holders available just in case a user wishes to exercise the upper body during a cycling session.  

This spin bike has the construction and the features that make it one of the indoor cycling bikes that could get you across the finish line of shedding weight and improving cardiovascular health.  

Click right here to have a peek at the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike on Amazon.  

The Frame and Construction 

Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike

The construction of the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike includes a solid triangular-shaped anti-corrosive welded steel frame and a belt guard that is made of ABS material for safety.  

Hence, the bike is certifiably sturdy and safe to support a maximum user weight capacity of 275 lbs./125 kg.  

Moreover, due to its step-thru design, shorter individuals won’t have difficulty mounting or dismounting it.  

When it comes to stability, you will be able to train without fear of wobbling or tilting. This is due to the base that features robust triangular steel stabilizers with adjustable levelers.  

That said, it is important to use the bike on a firm platform to prevent stability compromise, and to protect the floor from potential damage, the use of a rubber mat could be useful.  

This unit is a few inches larger than some indoor cycling bikes such as the Sunny Health & Fitness Pro SF-B901B, but it’s far from being bulky. It won’t overwhelm your space because its overall assembled dimensions are 49’’ long by 22’’ wide by 50.5’’ high.  

So, an area with perimeters of 4’1’’ length by 1’9’’ width will suffice for workouts. However, there should be at least 2’ of free space around the bike for safety and easy access reasons.  

Finally, users can easily relocate the bike around the room or apartment regardless of its weight due to the front-mounted transport wheels.  

The Seat of the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike 

The 4-way adjustable seat, tablet holder, handlebar, 30 lbs./14 kg flywheel, the LCD monitor, and magnetic resistance system of the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike

The seat is fairly comfortable; at least, no record shows otherwise. 

The seat’s dimensions are 10.5’’ long by 7’’ wide by 1.5’’ thick. In other words, it is cushioned and has a groove in the middle of it for air permeability. You should be able to train longer with some level of comfort.  

Since the seat’s connection mechanism, which includes a collar, is standard, it is easy to find a replacement if you wish to swap it. Although, using a gel seat cover is another way to improve it.  

The seat is 4-way adjustable; meaning, it can be adjusted vertically (upward/downward), and horizontally (fore/aft).  

Thus, users whose inner thigh to ankle measurements are between 27’’ to 37.5’’ can safely, and conveniently utilize the bike without issues.  

Also, the horizontal adjustments enable you to space the seat and the handlebar between 16’’-20.5’’.  

The Handlebar  

The handlebar is 2-way adjustable (upward/downward), complementary to the seat’s adjustability for optimum customization.  

It has a W-shape that offers multiple grips for different hand positions so that you can ride in standing posture, racing posture, and hill-climbing posture. 

It is generously coated with soft rubber foam material. This is intended to provide secure and comfortable grips that could enable you and everyone else to exercise frequently and longer without experiencing blisters or slippage.  

Moreover, HR sensors are integrated into it for heart rate reading and transmission when they are grasped during a workout.  

The Pedals 

The pedals attached are toe caged with adjustable safety straps. They are safe and accommodative, and they’re specially designed for standard gym shoes. No slippage will be experienced no matter the intensity of one’s pedaling.  

However, clip-in shoes cannot be used with these pedals, but they can be swapped if you so wish since the thread size is 9/16’’ standard. Thus, options are widely available.  

The Drive 

The Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike is equipped with a belt drive system. A drive system that is mostly preferred due to its smooth and quiet operation, and non-maintenance requirement.  

The drive’s elements include a durable anti-stretch belt, a belt wheel/pulley, a solid crankset, and crank-arms, and the 30 lbs./14 kg perimeter weight flywheel.  

Users that are within the stipulated weight the bike supports will be able to pedal while standing. They can exercise at their own convenient time without having to worry about somebody getting disturbed.  

Cycling while listening to music, or watching a TV show/movie is entirely doable because no noise interference will be heard from the bike.  

The pedals and the flywheel are fixed; hence, they spin together, making it possible for you to pedal in reverse for maximum effect on the muscle groups.  

Nevertheless, this also means you can’t coast as you could on a road bicycle. Therefore, it is only imperative to apply the emergency brake by pushing the tension control knob down before making a quick exit.  

The Resistance 

The Synergy SF-B1879 Indoor Cycling Bike has a manual magnetic resistance system that continues to keep the bike’s operation smooth and quiet.  

In other words, the bike’s operation remains the same even when the resistance is engaged. The heavy flywheel provides consistent momentum that guarantees vibration-free motion.  

The other notable aspect of the resistance system is that it provides unlimited resistance levels, and the elements involved, such as the magnetic brake pad, and the flywheel don’t make direct contact while generating resistance.  

Instead, resistance is generated when the magnetic brake pad emits magnetic fields on the top surface of the chrome-plated flywheel.  

Thus, no wear and tear will occur, and no part will require a replacement. 

To increase or decrease the resistance level, simply turn the tension knob on the mainframe tubing clockwise or anticlockwise, respectively.  

The resistance system provides easy to decent levels of challenging workouts that could rile up the body system for better physical fitness.   

The Console 

The Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike incorporates a console with a basic nonbacklit LCD monitor with a single navigation button.

The monitor tracks workout stats such as Time, Speed, Distance, Calories Burned, RPM, and Odometer; and they are displayed one at a time after every 6 seconds by the SCAN function.

Distance and Speed are measured in miles and mph, respectively, and the monitor also displays the Heart Rate data when the contact grips are grasped during a workout.  

Since the LCD monitor is not backlit, it is better to view it in an environment with good illumination for clarity.

When the bike is not active for 4 minutes, the monitor turns off but resumes when the activity returns.  

The monitor is powered by 2 AAA batteries which are included in the package.


A lady workouts with the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike while using dumbbells

There is a water holder, a tablet holder, and dumbbell holders included on this bike. These have a direct impact on how effective your workout gets.  

The tablet holder is designated on the handlebar, well above the console, and it can accommodate a large tablet device without blocking the view of the monitor.  

The water bottle holder is within arm’s reach, and it is intended to help users maintain proper hydration during a workout session. While the dumbbell holders enable users to use up to 20 lbs./9 kg dumbbells for upper body strength training.  


A lady moves the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike for storage

The bike is not foldable, however, it not large either to take up too much space. 

A storage area with perimeters of 4’1’’ length by 1’9’’ width will suffice. It can be stored in a garage, under the staircase, or better still leave it stored in a dedicated workout area.  

Due to its portability (it has got transport wheels at the front base), moving or relocating the bike around the room or apartment is not difficult. 

Approval Rating 

The approval rating of the Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike on Amazon is positive. Most users view it favorably, thus, they recommend it.  

Pros/Features Overview 

  • Sturdy, and stable 
  • Supports a maximum user weight capacity of 275 lbs./125 kg 
  • Portable with transport wheels for easy relocation process 
  • It has a belt drive system that provides smooth and quiet operation 
  • The integrated magnetic resistance system offers unlimited adjustable resistance levels without compromising the smooth operation of the bike 
  • The bike allows users to engage in cardiovascular exercises that lose weight, strengthen the core, arms, and lower body muscle groups  
  • The handlebar is multi-grip designed for standard posture, racing posture, and hill-climbing posture; and it is also coated with soft rubber foam material for firm and comfortable grips 
  • The toe caged pedals with adjustable safety straps guarantee secure footing stability  
  • The seat is 4-way adjustable, and it is more comfortable than most spin bike saddles 
  • It is possible to pedal in reverse to target more muscle groups 
  • The 30 lbs./14 kg high inertia perimeter weighted flywheel provides consistent momentum that stabilizes the operation of the bike 
  • The included LCD monitor tracks workout stats such as Time, Distance, Speed, RPM, Odometer, Calories Burned, and Heart Rate 
  • Contact grips for heart rate monitoring 
  • Water bottle holder for hydration purposes 
  • Tablet holder for entertainment purposes 
  • Dumbbell holders included 
  • Requires low maintenance 
  • Easy to assemble 


  • The monitor is not backlit  
  • The console not telemetric 



  • 3 Years for the Frame 
  • 180 Days for Parts and Components 

Product Dimensions and Specifications 

  • Length: 49’’ 
  • Width: 22’’ 
  • Height: 50.5’’ 
  • Shipping Dimensions: 41.5’’ L x 10’’ W x 34.6’’ H 
  • Net weight: 88.2’’ lbs./40 kg 
  • Gross weight: 102.5’’ lbs./46.4 kg 
  • Frame: Steel 
  • Flywheel: 30 lbs./14 kg  
  • Maximum user weight capacity: 275 lbs./125 kg 
  • Supported inseams: 27’’-37.5’’ 
  • Seat: 4-way adjustable; dim. 10.5’’ L x 7’’ W x 1.5’’ H 
  • Handlebar: 2-way adjustable 
  • Pedals: Toe cages with adjustable levelers 
  • Distance between the seat and the handlebar: 16’’-20.5’’ 
  • Drive: Belt 
  • Resistance: Manual magnetic, infinite resistance levels 
  • Monitor: Basic LCD 
  • 2 AAA batteries for the monitor included 
  • Water bottle holder included 
  • Tablet holder included 
  • Dumbbell holders (20 lbs./9 kg Capacity each) included 
  • Transport wheels: Yes 
  • Floor levelers included 
  • Contact grips for pulse 


The Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike is shipped out in a single box that contains the preassembled bulk, and other parts to be assembled.  

The box weighs 102.5’’ lbs./46.4 kg, and the dimensions are 41.5’’ long by 10’’ wide by 34.6’’ high.  

The shipping cost may differ because of the disparity in vendors’ policies. However, Amazon offers free shipping and gets it delivered in a couple of days.  


As aforementioned, the bike comes 80% preassembled. This means the heavy lifting has been done for you, and so, you only need to attach the stabilizers, the handlebar and the post, the pedals, and the console.  

This process takes only a couple of minutes to complete.  

Moreover, an instruction manual and the tools needed for the assembly are included in the package.  


Always wipe the bike clean after every workout session. Examine it before use to ensure that every part is tight and in good condition.  

Do not store in an area that is excessively or extremely hot, cold, or damp.  


The Sunny Health & Fitness Synergy SF-B1879 Indoor Cycling Bike is a decent cardio machine for home use. It has a manual magnetic resistance system, a belt drive system, 30 lbs./14 kg high inertia perimeter weighted flywheel, an LCD monitor, and more.  

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