| Unit | Size | Supported weight | Resistance | Exercise meter | Warranty |
|---|---|---|---|---|---|
Sunny SF-RB4876 Check Discounted Price | L:56.7" W:26.6" H:42.9" | 220 lbs | Manual magnetic, 8 levels | Time, Distance, Speed, Calories, ODO, SCAN, Goals | Frame: 3 years Parts: 180 days |
The Sunny SF-RB4876 is one of the recumbent bikes released by Sunny Health & Fitness in 2020. It’s a pretty basic exercise bike made for home use featuring a manual magnetic resistance system. In terms of features, it can be compared with the MaxKare model or the pooboo W258.
Key Features and Specifications
- Assembled dimensions: 56.7L x 26.6W x 42.9H inches (144L x 68W x 109H cm)
- Assembled weight: 51.85 lbs (23.5 kg)
- Max. user weight: 220 lbs (100 kg)
- Seat: Adjustable
- Drive: Belt
- Resistance: Magnetic, 8 levels
- Console: Time, distance, speed, calories, pulse, scan, goals
- Warranty: Frame 3 years / Parts 180 days
Frame construction
The Sunny Health & Fitness SF-RB4876 recumbent bike features a steel frame combining rectangular and 
cylindrical tubes in its construction. All the steel parts are coated with a corrosion-resistant paint finish, gray in color, this being the only color available for this model. The covers of the drive and resistance elements are made of ABS plastic, also gray in color to match the rest of the bike, with the “Sunny” logo in red.
Although it’s not as large as other fitness machines, such as treadmills, the Sunny SF-RB4876 bike takes quite a bit of space. It is approx. 56.7″ (144 cm) long, and 26.6″ (68 cm) wide. Plus, it is recommended to leave at least two feet of clearance all around if for ease of access.
The bike is not too heavy. Its net weight is approx. 51.85 lbs (23.5 kg). This being said, it can be carried and assembled by only one person. Plus, once it is assembled, it can easily be moved as its front base stabilizer is equipped with a set of small wheels. Conversely, the rear base stabilizer features a polygonal cap which can be rotated in order to serve as levelers.
The bike’s main chassis is a one-piece part, as opposed to other recumbent bikes, such as the SNODE R16 for example, which has a 2-piece frame. The one-piece frame definitely contributes to the bike’s overall sturdiness. Also, the seat is sustained by two upright support bars as opposed to only one bar.
One last aspect to mention here regards the bike’s step-through design. This feature can be quite a plus for users with certain disabilities as it allows easier entry and exit.
Seat and handlebars
The Sunny Health & Fitness SF-RB4876 recumbent exercise bike is equipped with a cushioned seat.
Both the backrest and bottom pads feature approx. 1.5″ (3.8 cm) of foam padding for improved comfort. Their covers are made of durable double-stitched vinyl material, black and silver, for improved aesthetics. The seat pad is approx. 16.9″ (43 cm) wide and 11.8″ (30 cm) long, pretty large for a light-capacity bike, so it provides plenty of contact surface. However, even though the base frame of the seat features two upright support bars, its weight capacity is only 220 lbs (100 kg).
The bike’s seat is adjustable. Its base rail offers an adjustment span of approx. 9″ (23 cm), for users with an inseam between 26″ and 35″ (66 – 89 cm). This means the bike should accommodate users between 5’2″ and 6’5″ (157 – 196 cm) allowing a complete leg extension. It’s also important to mention that the bike’s seat adjustment system involves a turn-knob. Therefore, it is recommended to adjust the seat while you are not seated.
The Sunny SF-RB4876 recumbent bike is equipped with two sets of handlebars, one attached to the seat assemble, the other to the front mast. The seat handlebars feature long grips, parallel with the seat pad. They are equipped with metallic pulse sensors and the included performance monitor does have a pulse reading function.
The front handlebars attach directly to the front mast of the bike via screws. They are non-adjustable and they do not integrate pulse sensors. They are curved upward in order to provide a parallel grip. Also, since the front upright mast of the bike is curved towards the user, holding the front handlebars during workouts does not lead to an awkward position as it is the case for other recumbent bikes.
Resistance and drive
The Sunny Health & Fitness SF-RB4876 recumbent bike features a magnetic resistance system with 
manual action. This means you don’t need an external power source or an adapter for it. But on the other hand, the bike cannot automatically adjust the resistance and the included performance monitor does not have workout programs.
The bike’s resistance system consists of an internal magnetic brake that is connected to the tension dial on the front mast through a steel cable. As you turn the dial, the brake moves closer or farther from the flywheel which adds or reduces the pedaling resistance.
The brake makes available 8 distinct tension levels. The first level provides a very light pedaling difficulty, which is great for users that require recovery training. The 7-8 levels, on the other hand, provide considerably more resistance, great for anyone who wants to burn more calories and improve their stamina.
Similar to other magnetic resistance exercise bikes, the Sunny SF-RB4876 features a belt drive system. It uses a durable poly-v belt for its internal transmission. This means you don’t have to take the covers apart to lubricate the drivetrain as it would be the case for a chain-driven bike. Also, the belt contributes to the overall smoothness of the ride.
The bike’s internal flywheel is perimeter-weighted for improved inertia. Its exact weight is not specified, but since the overall weight of the bike is only 51.8 lbs (23.5 kg), the flywheel probably does not exceed 20 lbs (9 kg). The flywheel allows pedaling in reverse as well. But as opposed to a road bike, this exercise bike does not permit coasting. When pedaling in reverse, you will get the same resistance as when pedaling forward.
This Sunny exercise bike is equipped with a durable crankset, but nonetheless, since it’s not a spin bike, it’s not made of standing up on the pedals; it is meant for seated workouts only. The included pedals are made of durable thermoplastic material. They are self-leveling, so they always turn face-up if you remove your feet from them. They are also equipped with adjustable straps for improved foot stability during pedaling.
Performance monitor
As we’ve mentioned above, the included performance monitor does not have pre-set workout programs. 
However, it does have a few more features than the average basic model. It is equipped with an LCD display that tracks time, distance, total distance, speed, calories, and pulse. Speed and distance are shown in MPH and miles; there is no option for changing them to metric units. Also, the monitor unit is not telemetric. It can only track your pulse if you hold on to the integrated sensors. It cannot communicate with a wireless HR chest strap like the Polar or ANT+ models.
The performance monitor unit features the standard 3-button keypad. The Mode button allows you to scroll through the workout values and select the one that you want to view on the display. It also offers the possibility to select the Scan Mode which rotates all the values showing each one for 6 seconds.
The Set button covers the target setting function. It gives you the possibility to select a workout target for time, distance, and calories. When a target is selected, the monitor counts down from the selected value until it reaches zero. And finally, the Reset button clears all the values on the monitor except the odometer which can only be reset if you remove the batteries.
The unit requires two AAA batteries as its power source which are included. It starts up when you press one of the buttons or when you begin pedaling. It also automatically turns off after 4 minutes of inactivity on the bike.
Two other notable features to mention here are the device holder and the heart rate zone sticker. The device holder consists of a small shelf placed above the display. It is large enough to accommodate most tablets and smartphones. However, the monitor unit does not have a USB port or other ports to connect your device to it. The HR sticker is a nice touch to have at hand if you want to keep in a certain BPM zone without consulting the manual.
Assembly and Maintenance
The bike’s drive mechanism comes pre-assembled, attached to the base frame with the covers already in place. You only have to attach the two base stabilizers, the seat, the handlebars, the pedals, and the performance monitor. This shouldn’t take more than an hour of your time. The task is fairly simple and the manual provides all the necessary instructions. A basic toolkit is also included.
Once the bike is assembled, you don’t have to worry too much about maintenance. The internal parts and the drive train don’t require any lubrication. So, you only have to keep the bike clean, and periodically check for loose bolts or parts.
The Pros
- Sturdy, one-piece frame;
- Adjustable stabilizers on the rear base;
- Transport wheels on the front base;
- Cushioned seat and backrest;
- Adjustable seat;
- Quiet magnetic resistance system;
- Adjustable resistance offering distinct 8 levels;
- Self-leveling pedals with straps;
- Performance monitor that can track time, distance, total distance, speed, and calories burned;
- Goal settings for time, distance, and calories;
- Device holder included;
- Fairly easy to assemble;
- Little to no maintenance required;
- Excellent warranty.
The Cons
- No bottle holder;
- No backlight on the display of the meter unit.
Summary
The Sunny Health & Fitness SF-RB4876 is a recumbent exercise bike made for home use. It features a manual magnetic resistance system with 8 difficulty levels, a comfortable, 2-way adjustable seat, and a performance monitor that tracks time, distance, speed, pulse, and calories burned. It’s a fairly decent recumbent bike, great for light cardio training, muscle toning, and weight loss offering excellent value for the price.