Sunny Health & Fitness SF-RB4958 Recumbent Bike

Content Protection by
Sunny SF-RB4958

Check Discounted Price
265 lbsManual
8 levels

The Sunny SF-RB4958 is one of the recumbent exercise bikes released by Sunny Health & Fitness in the second part of 2019. It’s pretty much the recumbent version of the Sunny SF-B2952 upright bike. It’s a trainer made for home use, it doesn’t have online connectivity or preset programs, but it’s a pretty durable bike offers excellent adjustability.

Key Features and Specifications

  • Assembled dimensions: 62L x 27W x 46H inches (157L x 69W x 117H cm)
  • Assembled weight: 79.3 lbs (36 kg)
  • Weight capacity: 265 lbs (120 kg)
  • Seat: Adjustable
  • Pedals: Weighted, with straps
  • Resistance: Manual magnetic, 8 levels
  • Console: Time, distance, odometer, speed, calories, pulse, goals, BMI, recovery, SCAN
  • Extras: Bottle holder, tablet holder, HR zone sticker
  • Warranty: Frame 3 years / Parts 180 days

Frame construction

The Sunny Health & Fitness SF-RB4958 is a fairly large recumbent bike compared to other models. With the frame fully assembled, it is approx. 62″ (157 cm) long, and 27″ (69 cm) wide. It is also recommended to leave at least two feet of clearance all around it for ease of access.

The bike it pretty solid as well. It is rated for a maximum user weight capacity of 265 lbs (120 kg), but most importantly, its seat assembly is sustained by two steel bars which considerably improve its sturdiness.

The bike combines steel and ABS parts in its construction. Needless to say, its frame is made of steel tubing. Its main chassis is a one-piece part with the seat sustaining bars, and the console mast base precision-welded to it. All the steel parts are coated with a thick, rust-resistant paint finish, gray in color. The only major ABS parts are the covers of the drive system and the covers of the seat rail base.

The fully assembled bike is not extremely heavy but does weigh approx. 79 lbs (~36 kg). This weight delivers excellent stability. Plus, the bike’s rear base is equipped with adjustable levelers.

The bike is easy to move once it is assembled. Its front base integrates transport wheels. So, by lifting the unit from one of its rear bars and using these wheels to relocate the bike, you will only have to handle 30% or less from its total weight.

Seat and handlebars

The Sunny Health & Fitness SF-RB4958 recumbent bike has a seat similar to the SF-RB4850 model. To begin with, its bottom pad is heart-shaped, featuring 1.5″ (4 cm) of foam padding. Its cover is made of durable faux leather. It’s also fairly large; it measures 15″ (38 cm) in width and 11″ (28 cm) in depth, offering plenty of contact surface.

The backrest features a heavy-duty ABS frame with a mesh structure for superior breathability and flexibility. It is approx. 18″ (45 cm) long, and 16″ (40 cm) wide, and slightly arched for extra comfort. It doesn’t have a reclining system and cannot be adjusted independently from the rest of the seat.

The whole seat assembly is adjustable. It is attached to a durable rail system. The rail offers an adjustment span of 8″ (20 cm), for an inseam length between 30″ and 38″ (76 – 96 cm). Therefore, the bike can accommodate users between 5’2″ and 6’5″ (157 – 196 cm). The seat base is pretty solid as well. It could probably hold users heavier than 300 lbs (136 kg), but due to the ABS/mesh construction of the backrest, the bike’s specified weight capacity is only 265 lbs (120 kg).

The seat’s adjustment system is lever-based. This is quite a plus as you can adjust the seat position while you are seated.

The bike is equipped with two sets of handlebars; one is attached to the seat assembly, the other to the front mast of the bike. The seat handlebars are equipped with metallic EKG sensors. Therefore, by holding on to them, the console can monitor your heart rate.

The front handlebars don’t have sensors. They offer the possibility of adopting several grips. Both sets of handlebars have rubberized grips. None of them are adjustable.

Drive and resistance

The Sunny SF-RB4958 is equipped with a manual magnetic resistance system. Therefore, it doesn’t require an external power source. Also, the console doesn’t have preset programs and cannot automatically control the resistance.

The bike’s resistance system consists of an internal magnetic brake which is connected to the tension knob on the front upright bar through a steel wire. By turning the knob clockwise, the brake moves closer to the flywheel which increases the overall pedaling difficulty.

The bike offers 8 tension levels. The 1-3 levels deliver a fairly light resistance, great for recovery training or low-intensity workouts. The 8th resistance level on the other hand, offers considerably more pedal tension, simulating a hill climb and allowing a more intense workout.

The bike’s internal flywheel is perimeter-weighted. This means it adds stability and a bit of extra inertia to the ride. Its exact weight is not specified, but considering the total weight of the bike, it probably isn’t heavier than 20 lbs (9 kg).

The flywheel is bi-directional. Therefore, you can pedal in reverse if you want. However, coasting on the bike is not possible, and when pedaling in reverse, you will benefit from the same pedal resistance as when pedaling forward. Also, when pedaling in reverse, the bike’s console should continue to monitor your workout data.

The Sunny SF-RB4958 recumbent exercise bike features a belt drive system. Therefore, internal lubrication is not necessary. Plus, another advantage of a belt drive system is the whisper-quiet pedaling motion. It also generates considerably less vibration than a chain drive.

Finally, the bike is equipped with a durable crankset featuring steel arms. The pedals have a weighted design; thus, they always self-level if you remove your feet from them. They have a non-slip surface and adjustable straps.


Although the bike’s console doesn’t have any preset programs or online connectivity, it provides quite a few features in order to render your workouts more challenging. First of all, it is equipped with a large LCD display divided into 6 sub-sections. The bottom smaller sections show speed, RPM, time, distance, calories, and pulse. Speed and RPM share the same section; they’re shown alternatively. The top larger section gives you the possibility to either select one of these metrics to be shown at all times, or select the Scan mode and each one will be shown for 6 seconds.

The unit is not telemetric. In other words, it cannot communicate with any wireless HR transmitter. So, if you want to monitor your pulse, you will have to hold on to the integrated sensors. Also, the speed and distance metrics are set by default to in imperial units (MPH and miles) and there is no setting for metric units.

The console unit offers target settings for time, distance, calories, and pulse. If a target is selected for any of these workout metrics, the console will show the remaining amount until you reach that particular target. If a target is selected for heart rate, the console will beep when you achieve the selected pulse rate.

A Recovery function and a BMI function are also available. The Recovery function requires you to use the pulse sensors. It measures the amount of time your heart takes to return to a normal BPM after the workout, and based on the result, it will give you a fitness rating between F1 (best) and F6 (poor). The BMI (Body Mass Index) function calculates your percentage of body fat based on the personal data that you input, such as height, weight, age, and gender. Therefore, these two applications give you the possibility to keep track of your fitness level and weight loss.

The console unit is battery-powered. It requires two AA batteries which are included. It starts up when you press one of the buttons or when you begin pedaling, and also automatically shuts down if it doesn’t detect any activity on the bike for several minutes. Before shutting down, in idle mode, the display will show room temperature, clock, and current date.

Two other notable features of the bike’s console are the tablet holder and the HRC sticker. The tablet holder consists of a small tray placed above the console display; this tray is large enough to accommodate any tablet. The HRC sticker is placed on the top section of the console and shows a grid with the heart rate zones that you should aim for depending on your age, in order to benefit from a better aerobic output, fat burn, etc.

Assembly and Maintenance

The main chassis of the bike comes pre-assembled, with all the drive and resistance elements already in place and protected by the ABS covers. However, you will still need to attach the two base stabilizers, the front post, connect the tension wires, the console, the seat, the backrest, and the pedals. This may take more than one hour, but the task is pretty straightforward. The manual provides very clear, step-by-step assembly instructions and all the necessary tools are included.

Once the bike is assembled, you don’t have to worry too much about maintenance. It’s a belt-drive bike, so its internal transmission doesn’t need any lubrication, nor do the other internal parts. Therefore, all you need to do in terms of maintenance is basically keep the unit clean and periodically inspect it for loose bolts and parts.

The Pros

  • Sturdy construction – can support users up to 265 lbs;
  • Adjustable rear stabilizers;
  • Transport wheels on the front base;
  • Step-through frame design for easy access to the seat;
  • Seat handlebars with pulse sensors;
  • Front handlebars included;
  • Padded for optimal comfort;
  • Contoured backrest with a flexible mesh structure;
  • Multiple adjustment positions on the seat rail;
  • Adjustable magnetic tension offering 8 difficulty levels;
  • Weighted pedals with adjustable straps;
  • Exercise meter that can track time, distance, total distance, speed, calories, and pulse;
  • Goal setting functions for time, distance, and calories;
  • Temperature, clock, and date display when in idle mode;
  • Tablet holder included;
  • Bottle holder included;
  • HRC sticker on the top section of the console;
  • Fairly easy to assemble;
  • Tools for assembly are included;
  • Little maintenance required;
  • Excellent warranty.

The Cons

  • No online connectivity;
  • No backlight on the console display.


The Sunny Health & Fitness SF-RB4958 is a mid-range recumbent bike made for home use. It is equipped with an 8-level manual magnetic resistance system, a comfortable padded seat with mesh backrest, and a console that can track all the important workout metrics. It’s an excellent exercise bike for light to medium-intensity cardio workouts, stamina development, muscle toning, recovery training, and weight loss.

Content Protection by

Leave a Comment

Your email address will not be published. Required fields are marked *