| Unit | Size | Supported weight | Flywheel weight | Resistance | Console |
|---|---|---|---|---|---|
Sunny SF-B1709 Check Discounted Price | L: 53.2" W: 23.6" H: 54.3" | 300 lbs | 7.3 lbs | Manual magnetic, 13 levels | Time, Distance, Speed, Cadence, Calories, Pulse, Goals, Race program |
Next to the Sunny SF-B1735, the Sunny SF-B1709 is one of the new models released by Sunny Health & Fitness at the beginning of 2019. It’s a magnetic resistance indoor cycling trainer featuring a design that can be compared to the Keiser M3i. It is a more affordable alternative to the Keiser bike, though. There are several important aspects that you need to know about this exercise bike. So, in this post, we’re going to cover in detail each and every one of its features.
Technical Details and Specifications
- Assembled dimensions: 53.2L x 23.6W x 54.3H inches (135L x 60W x 138H cm)
- Assembled weight: 89.2 lbs (40.4 kg)
- Flywheel weight: 7.3 lbs (3.3 kg)
- Supported weight: 300 lbs (136 kg)
- Seat: 4-way adjustable
- Drive: Belt
- Resistance: Magnetic, 13 levels
- Fitness meter: Speed, average speed, max. speed, cadence, average cadence, max. cadence, time, distance, calories, pulse, race program
- Extras: Bottle holder
- Warranty: Frame 3 years / Parts 180 days
Frame construction
The Sunny Health & Fitness SF-B1709 features a heavy-duty construction; its frame is composed of ovalized
steel tubes coated with a corrosion resistant paint finish. The color used for the main body of the bike is black, while the seat and handlebar posts are chrome plated. The bike’s frame and crank are designed to support users up to 300 lbs (136 kg).
Of course, there also are ABS parts in the bike’s construction. The side covers of the drivetrain and resistance system are made of durable ABS material. However, these do not influence the overall sturdiness of the frame. Their only role is to secure the unit’s internal mechanism.
Compared to other indoor cycling bikes, such as the PooBoo D525 for example, the Sunny SF-B1709 is slightly larger. It is approx. 53″ (135 cm) long, and 23.6″ (60 cm) wide. This footprint provides plenty of stability. Plus, the base bars are equipped with adjustable stabilizers with large rubber pads. Thus, you can perfectly level the unit on any type of floor, and a rubber mat is not necessary for it.
This Sunny exercise bike is lighter than other spin bikes such as the Spinner P3, for example. But that’s mostly because it is equipped with a lighter flywheel and a magnetic resistance system. It weighs approx. 89 lbs (40.4 kg), though, which still is more than twice the weight of the average road bike, weight that is reflected in the unit’s overall stability as well.
One last aspect to mention here regards the ease of transport. The front base of the bike is equipped with two large silicone wheels which facilitate its relocation once you have finished your workout.
Seat and handlebars
The Sunny Health & Fitness SF-B1709 offers superior micro-adjustability. To begin with, the seat is 4-way 
adjustable (up, down, forward, and backward). Its upright post has 9 adjustment positions, while the horizontal slider also offers several inches of front-to-back adjustment. This being said, the bike can accommodate users with an inseam between 28″ and 39″ (71 – 99 cm). Differently put, it should be able to accommodate users between 5’0″ and 6’6″ (153 – 198 cm) with no problem, allowing a complete leg extension.
The included saddle is designed for superior comfort. First of all, it integrates a thick layer of cushioning, especially in its rear part. It is also equipped with two shock absorption springs at the rear. Its upholstery is made of durable, double-stitched faux leather. Plus, it has a central cutout which improves breathability.
The bike’s handlebar assembly is also 4-way adjustable (up, down, forward, and backward), just as the seat. Its upright post has 8 adjustment notches and its horizontal slider offers approx. 2 inches of travel.
The handlebar has a multi-grip design. It integrates a loop aero bar and two drop-down grips. Therefore, you can adopt an aero grip, a race grip, a standard grip, and more. It also integrates pulse sensors, so the exercise meter can monitor your pulse rate.
Both the handlebar and the seat are very easy to adjust. They’re equipped with large turn-and-pull knobs very easy to grip, unlock and re-lock. Thus, it shouldn’t take more than a minute to adjust the bike to your size.
Drive system
As we’ve mentioned above, this Sunny bike is equipped with a considerably lighter flywheel than other spin 
bikes. It only weighs 7.3 lbs (3.3 kg). Also, it’s not perimeter weighted so it does not provide a highly aggressive inertia. But nonetheless, due to the magnetic resistance system, the bike provides an excellent difficulty range, great for all kinds of spin workouts.
The placement of the flywheel is a plus as well. Since it’s placed at the rear, away from your body, it’s less likely for sweat drops to fall on it. Even if it chrome-plated, and the body of the bike has a corrosion-resistant paint, sweat can still be corrosive for small parts such as screws, washers, or nuts.
The flywheel is bi-directional. It gives you the possibility to pedal in reverse. But due to the simple construction of the drivetrain, you cannot coast on the bike. So, when you pedal in reverse, you will benefit from the same pedaling difficulty as when you pedal forward.
The Sunny SF-B1709 uses a belt drive system. It integrates a durable poly-v belt which provides a very smooth and quiet pedaling motion. Also, as opposed to a chain drive, it does not require lubrication.
Finally, the bike’s crankset is a heavy-duty 3-piece part featuring solid steel crank arms and metallic alloy pedals. It can support most spin workouts even if the user is close to the maximum weight capacity. The pedals are equipped with adjustable toe cages on one side and SPD clips for spin shoes on the other. They also have standard threads, so in case you want to replace them, compatible pedals are widely available.
Resistance system
The Sunny Health & Fitness SF-1709 indoor cycling trainer is equipped with a manual magnetic resistance 
system. This means you don’t have to connect the bike to a power source. Also, the console is not connected to the tension system and the selected tension level is not displayed on its screen.
The bike’s resistance system consists of a magnetic brake concealed by the ABS side covers. The brake is connected to the tension lever on the front tube of the frame through a steel wire. By pressing the lever down, the magnetic brake covers a larger portion of the flywheel, thus increasing the pedaling difficulty. It also fulfills the role of an emergency brake; you can press it all the way down to quickly stop the flywheel from spinning.
The bike’s resistance system offers 13 distinct tension levels. The first level provides a fairly light pedaling difficulty, great for beginners or users who require recovery training. Conversely, the top resistance settings simulate a steep climb, giving you the possibility to achieve a high muscle burn and a quick cardio boost.
Exercise meter
The meter unit included with the Sunny SF-B1709 offers quite a few more features than a basic unit. It is
similar to the one included with the Sunny SF-1735 model. To begin with, its LCD display is divided into four distinct windows. The top one covers the Race program. The 2nd window covers speed and cadence. The 3rd window shows distance and watts, and the bottom window covers time and pulse.
The speed and distance are shown in imperial units. There is no option for selecting metric units. For pulse reading you have to use the integrated sensors; the meter is not telemetric, and therefore, it cannot read your pulse through a wireless chest strap transmitter.
The meter unit allows you to set goals for time, distance, calories, and for the race program. When a goal is set for time, distance, and calories, the display will show the remaining value towards that goal.
The Race program also allows you to set a goal for your Cadence. This is displayed by a segmented bar and your current Cadence is shown right under it. If you pedal slower, the Cadence bar will fall under the selected Cadence target so you’ll know that you have to pedal faster. Conversely, if the Cadence bar exceeds the target Cadence, you should pedal slower.
The console unit uses two AAA batteries as its power source. These are included with the bike. It starts up when you press the Mode button or when you begin pedaling. It also has a self-shutdown function which initiates if the sensor does not detect any input on the bike.
Assembly and Maintenance
The main frame of the bike with all the drive and resistance elements comes pre-assembled. Therefore, you only need to attach the base stabilizers, the seat post, the saddle, the handlebar post, the handlebar, the fitness meter, and the pedals. This shouldn’t take more than an hour. The manual offers very clear assembly instructions and all the tools required for the assembly are included.
The bike’s internal parts do not require any lubrication. So, basically, the only maintenance that you must take care of is keeping the unit dust-free, and periodically check for loose parts and bolts.
The Pros
- Durable steel frame – can hold users up to 300 lbs;
- Aesthetic design;
- Adjustable stabilizers on both bases;
- Transport wheels on the front base;
- 4-way adjustable seat;
- 4-way adjustable handlebar, with a multi-grip design;
- Pulse sensors integrated into the handlebar;
- Balanced flywheel for a smooth pedaling motion;
- Heavy-duty crank made for standing up spin workouts;
- Metallic alloy, dual-sided pedals, with toe cages on one side, and SPD clips for spin shoes on the other;
- Frictionless, wear-free, magnetic resistance with 13 levels;
- Smooth and quiet belt drive, great for apartment use;
- Fitness meter that tracks time, distance, speed, cadence, calories, and pulse;
- Goal settings for time, distance, and calories;
- Race program;
- Bottle holder included;
- Easy to assemble;
- Little maintenance required;
- Decent warranty.
The Cons
- The fitness meter does not have backlight;
- No online connectivity for the fitness meter.
Summary
The Sunny Health & Fitness SF-B1709 is an indoor cycling bike equipped with a 13-level magnetic resistance system, a heavy-duty crank, and dual-sided pedals. It offers superior micro-adjustability, it includes a high-comfort seat, and a multi-grip handlebar with aero bars and drop down grips. It also includes a fitness computer with a race program for cadence and goal settings. It’s a sturdy and good-looking exercise bike, perfect for a wide range of cardio workouts, muscle toning, stamina and strength development, interval training, and weight loss.