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Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike Review

Stationary recumbent bikes are a great help to those who want to stay fit but not with exercises that may impact joints. They are also great during these days of coronavirus pandemic as fitness lovers can exercise on it without leaving their home.

However, the prices of recumbent bikes may be higher than the traditional upright bikes and this fact may deter buyers. In such a condition, Sunny Health & Fitness has come up with their SF-RB4850 recumbent bike which is one of the least expensive recumbent bikes on the market. This bike also has quite a few features for the price and thus is expected to attract exercise enthusiasts.

Published: January 21, 2022.

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Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike Specifications

- Dimensions: 59 x 26 x 47.5 inches (150 x 66 x 121 cm) (L x W x H)

- Weight: 86.5 lbs. (39.4 kg)

- Power requirement: 1 Amp (100-240V)

- Maximum user weight capacity: 300 lbs. (135 kg)

- Resistance: Magnetic 16 levels

- Warranty: 3 years on structural frame, 180 days on other parts and components

Features of Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike


The assembly of the Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike is quite elaborate, but not difficult. The base frame and drive and resistance components are pre-assembled. Users have to connect the front and rear bases, the console mast, the console, the seat assembly, the front handlebars, and the pedals.

Since the machine is fairly heavy, assembly needs 2 persons and takes around a couple of hours to finish. The user manual contains all the assembly instructions in detail and the package includes all the required tools.


The frame of the SF-RB4850 is made of strong steel alloy. Its color is black. The construction and design of the frame is strong and aesthetically pleasing.


This bike is not very large like other exercise machines. Still, it’s 59” (150 cm) long and 26” (66 cm) wide. Plus, one should keep a clearance of 2 feet on all its sides for safe and comfortable access and operation.


The SF-RB4850 is a quite heavy weighing around 86.4 lbs. (40 kg). But this weight offers it excellent stability. Plus its rear base features two dials on its caps which can be turned clockwise to lower and counterclockwise to raise. Thus they act as stabilizers.


Although the SF-RB4850 is fairly heavy, it’s not difficult to move around, thanks to the transportation wheels featured on the front base and a lifting handle on the rear base.

Step-thru Design

The SF-RB4850 features a step-thru design to allow users to easily step in and out from the bike. This is particularly useful for the elderly, injured, or ill users.

Maximum User Weight Capacity

The maximum user weight capacity of the SF-RB4850 is 300 lbs. (135 kg).

Electricity Operated

The SF-RB4850 operates on electricity and the power source should be of 1 amp (100-240V); thus before plugging the unit in, the user should confirm that their power source is correct.

However, users can even use the bike without connecting it to a power source. In that case, the console won’t turn on and thus, users cannot adjust the resistance level or use any other functions.


The console of the SF-RB4850 features a digital display.


It has the following keys:

Start/Stop: This button has 3 functions: 1. starts and pauses workouts 2. Starts body fat measurement 3. If held for 3 seconds, it resets all stats values to zero

Down: This key performs 2 functions: 1. lowers the resistance level during exercise 2. Reduces the value of the selected parameter

Up: This key has 2 functions: 1. Increases the resistance level during exercise 2. Increases the value of the selected parameter

Enter: This key can be used to input the value or mode

Recovery: A user can enter the Recovery function with this button when the heart rate value is displayed on the console. It displays values from F1 to F6, among which F1 is poor recovery heart rate, whereas F6 shows excellent recovery heart rate.

Mode: This button helps the user during exercise to switch the display from RPM to SPEED, WATT to CALORIES, and ODO to DIST.

The console displays workout stats like Time, Distance, Speed, Calories, Watt, Heart Rate, Target Heart Rate, Program, and Level.

The console also has a built-in BMI calculator.

The bike features 7 basic workout modes viz. Manual, Pre-set Programs, Body Fat Program, Watt Program, Heart Rate Control Program, Target Heart Rate Program, and User Program.

The console features the following functions:

Time: The ‘Time’ function accumulates the exercise time from 00:00 to 99:59. Users can preset their desired target time.

Distance: The ‘Distance’ function accumulates the workout distance from 0:00 to 999.9 miles. Users can preset their desired target distance.

Speed: This function displays the current exercise speed. The maximum speed is 99.9 MPH.

RPM: This function displays current rotations per minute.

Calories: This function accumulates the calories burned from 0 to 9999. Users can preset their desired target calories.

Heart Rate: This displays the current heart rate in beats per minute.

Target Heart Rate: This function helps users preset their Target Heart Rate

Watt: This displays the current watt.

Program: This helps users choose one of the 24 different training programs.

Level: The program has 10 columns of bars and each column has 8 bars. Each column denotes a 1-minute exercise and each bar denotes 2 resistance levels.

ODO: This function displays the total accumulated distance from 0 to 9999 miles.

The console turns off if the bike remains inactive for 4 minutes. To start it again the user can press any key on it.

Workout Programs

The SF-RB4850 features 24 workout programs. These include:

- 1 Manual Program (P1)

- 12 Pre-set Programs (P2 to P13)

- 1 Watt Control Program (P14)

- 1 Body Fat Program (P15)

- 1 Target Heart Rate Program (P16)

- 4 Heart Rate Control Programs (P17 to P20)

- 4 User Programs (P21 to P24)

The 4 User Programs help users set their own program which they can use immediately.


Seat and Backrest

The seat of the SF-RB4850 can be adjusted back and forth. It’s attached to a rail on which it can be moved closer or farther from the pedals offering an inseam length ranging from a minimum of 30” (76 cm) to a maximum of 40” (101 cm).

Thus users of height between 5’2” (157 cm) and 6’5” (196 cm) can use the bike with no problem with full leg extension and an appropriate range of motion.

Since the adjustment technique is lever-based, users can adjust the position of the seat without having to get up. The lever is placed on the right side of the seat and users can shift the lever down to loosen and move the seat to the desired position and then shift it up to secure.

The seat has been made super comfortable with extra padding and foam cushioning to ensure proper blood circulation in the glutes so users can perform prolonged and forceful exercises. The extra padding helps relax the tail bone while sitting and saves users from an urge to fall asleep that arises when circulation is cut off. It’s also contoured and extra-large to accommodate a wide range of users’ sizes.

The backrest too is equally comfortable and offers superior breathability with its mesh material. It’s around 20” (50 cm) long and 18” (46 cm) wide. It’s been slightly arched for added comfort. The backrest cannot be adjusted independently from the seat.


The SF-RB4850 has two sets of non-adjustable handlebars, one attached to the seat assembly while the other attached to the front mast below the console. The seat handlebars have metallic pulse sensors holding which users can view their heart rate on the console. The higher one’s elevated heart rate, the more calories are burned.

All the handlebars have rubberized covers for improved grip and comfort.


The SF-RB4850 features an automatic magnetic resistance system. Thus the bike can automatically adjust the pedal resistance and run on electricity. The package includes a power adapter. The resistance being magnetic offers a virtually quiet and smooth-riding motion.

There are 16 levels of resistance of which the first three offer a light resistance that is recommended for improving heart and lung function. The last 15th and 16th levels on the other hand are meant for an increased heart rate in a shorter duration and a higher calorie burn. Users can adjust the resistance simply by turning the knob.


The resistance system of the SF-RB4850 is belt-driven and therefore requires no lubrication and also produces less vibration than that by a chain drive.


Pedals of the SF-RB4850 are textured, non-slip, weighted, and self-leveling, and have adjustable straps to accommodate feet of most sizes.


The first add-on on the SF-RB4850 is a bottle holder attached to the front mast so users can keep a water bottle at hand and keep themselves hydrated.

The other add-on is a device holder positioned just above the console, so, users can watch exercise videos or entertainment shows on their devices while exercising.


Maintenance of the SF-RB4850 is simple. It doesn’t require any lubrication for its internal parts, at least not for a very long time. All users have to do is to keep the machine clean and regularly check if there are any loosened parts and bolts and tighten them if needed.

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Pros of Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike

- Strong steel alloy frame

- Strong and aesthetically pleasing design

- Excellent stability

- Transportation wheels and lifting handle included for easy relocation

- Step-thru design

- 300 lbs. maximum user weight capacity

- Console with multi-functional digital display

- 24 workout programs

- 16 magnetic resistance levels

- Belt driven resistance system for smooth and quiet operation

- Super-large comfortable and adjustable seat with extra padding and foam cushioning

- Extra-large backrest offering excellent lumbar support and superior breathability with its mesh material

- Seat handlebars as well as front mast handlebars with rubberized grips included

- Seat handlebars feature heart rate sensors

- Textured, non-slip, weighted, and self-leveling pedals with adjustable straps

- Bottle holder included

- Device holder included

- Easy assembly

- Almost no maintenance

Cons of Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike

- Assembly is time-consuming and needs 2 people

- Heavy

- Somewhat short warranty

- No chest strap included for heart rate monitoring

- No other add-ons like workout fans or speakers

Bottom Line

sunny sf rb4850 mThe Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike is an excellent exercise machine for those who would prefer to exercise at home.

It has a lot of features for the price. It’s strong and sturdy, portable, with a step-thru design for easy entrance and exit, 300 lbs. of maximum user weight capacity, multi-functional console, 16 magnetic resistance levels, 24 workout programs, belt-driven resistance system for smooth operation and low maintenance, comfortable and adjustable seat and backrest, heart rate sensors integrated into the seat handlebars, textured pedals with adjustable straps, and add-ons like water-bottle-holder and device holder.

Thus this is an excellent machine for cardio workouts, muscle building and toning, stamina buildup, calorie burn, weight loss, and recovery training without an impact on joints and at an affordable price.

For more reviews and recommendations, feel free to follow the Sunny Health & Fitness SF-RB4850 Programmable Recumbent Bike Amazon link (link opens in the new window).

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