| Unit | Size | Supported weight | Flywheel weight | Resistance | Exercise meter |
|---|---|---|---|---|---|
Sunny SF-B1964 Check Discounted Price | L:48.8" W:20.1" H:49.2" | 275 lbs | 40 lbs | Manual magnetic | Time, Distance, Odometer, Speed, RPM Calories, Pulse Scan |
The Sunny Health & Fitness SF-B1964 indoor cycling bike is pretty similar to the SF-B1995 model. However, it features a magnetic resistance system. It also includes a dumbbell holder.
Key Features and Specifications
- Assembled dimensions: 48.8L x 20.1W x 49.2H inches (124L x 51W x 125H cm)
- Assembled weight: 105.4 lbs (48 kg)
- Flywheel weight: 40 lbs (18 kg)
- Supported weight: 275 lbs (125 kg)
- Seat: 4-way adjustable
- Resistance: Manual magnetic
- Drive: Belt
- Fitness monitor: Time, speed, distance, odometer, RPM, calories, and pulse
- Extras: Bottle holder, device holder, dumbbell holder
- Warranty: Frame 3 years, Parts 180 days
Frame construction
The Sunny SF-B1964 indoor cycle features a pretty standard triangular frame construction. It’s made of rectangular
steel tubing double-coated with a corrosion-resistant paint finish. The color used for the main frame is dark gray, while the seat and the handlebar posts are painted black. These are the only colors available for this Sunny exercise bike, at least for the moment.
Like most other spin bikes, the Sunny SF-B1964 is not a large fitness machine. With all the parts assembled, it is approx. 48.8″ (124 cm) long, and 20.1″ (51 cm) wide, while its highest point, with the handlebar, extended all the way up, is 49.2″ (125 cm).
The bike is fairly heavy. Its net weight is 105.4 lbs (48 kg). This being said, the transport of the packaged unit requires two people. However, once it is assembled, it can easily be moved by only one person as its front base bar features two large transport wheels.
On the other hand, this impressive weight considerably improves the bike’s overall stability. It also has a low center of gravity which also adds to its stability. Plus, both base bars are equipped with adjustable stabilizers.
Last but not least, the bike has a step-up element. This is the short horizontal bar at the base of the seat tube. Not all spin bikes have this element, so it is quite a plus as it can help with mounting and dismounting, as well as a support point for stretching and other exercises.
Seat and handlebars
The Sunny Health & Fitness Pro II SF-B1964 indoor cycling trainer Is equipped with a four-way adjustable
(up, down, front, back) seat. Its upright post features several adjustment positions while its horizontal slider adds a few extra inches of front-to-back adjustment. This being said, the bike should be able to accommodate users between 5’0″ and 6’4″ (153 – 193 cm). It is also rated for a maximum user weight limit of 275 lbs (125 kg) which is not bad for a home-use bike.
The included saddle is designed for superior comfort. It is built on a durable nylon shell with a thick layer of foam cushioning. It is contoured with a large cutout in the middle for improved breathability. Its attachment system is collar-based which not only allows a bit of angle adjustment, it also makes it easy to replace while compatible options are widely available.
The Sunny SF-B1964 exercise bike is equipped with a multi-grip handlebar. It offers the possibility to adopt a standard grip, a cruising grip, a climbing grip, and a close grip. It also has a long loop bar in the middle for an aero grip and a close parallel grip.
The handlebar is covered by a layer of PVC foam for an improved grip. Its side grips integrate pulse sensors and in included fitness monitor has a pulse reading function. It is only two-way adjustable (up, down); it does not have a horizontal slider like the seat for front-back adjustment.
Drive system
The Sunny SF-B1964 indoor cycling bike is equipped with 40 lbs (18 kg) flywheel which is also perimeter-weighted in 
order to provide a superior inertia and a consistent momentum. This type of flywheel construction is great for spin workouts and due to its weight, exercising on this bike not only improves your stamina but your leg muscle strength as well.
The flywheel allows reverse pedaling which is a plus as you can put some diversity into your workouts alternating forward pedaling with backward pedaling. However, coasting on the bike is not possible. The pedals continue to spin for as long as the flywheel is spinning. Also, when pedaling in reverse, you will get the same resistance as when pedaling forward and the monitor will continue to record your distance, speed, etc.
The bike is equipped with a belt drive system. It integrates a poly-v belt highly resistant to stretching, designed for improved traction. A belt drivetrain comes with two main advantages. One, you don’t have to lubricate it. And two, it generates slightly less vibration than a chain, so the pedaling motion is very smooth.
The bike’s crankset features solid steel, oval arms, painted black. The pedals are made of aluminum alloy, pretty durable as well, meant to withstand any type of spin workout even if the user is close to the maximum specified weight limit (275 lbs). The pedals don’t have SPD clips for spin shoes, but they do have toe cages. Their threads are 9/16″, so in case you will ever need to replace them, compatible options are widely available.
Resistance system
The Sunny Health & Fitness Pro II indoor cycling bike is equipped with a manual magnetic resistance system. 
This means you don’t need to connect it to a power source and you don’t need a power adapter or power cord for it. However, the bike does not adjust the resistance automatically.
The bike’s resistance system consists of a magnetic brake attached under the main oblique tube of the bike and to the tension knob. Therefore, when you turn the knob clockwise, the magnetic brake pad moves closer to the flywheel which increases the pedaling difficulty. The main advantage of a magnetic brake is that the brake pad does not touch the flywheel. Thus, the pedaling motion is drag-free, seamless, and whisper-quiet.
The bike’s tension knob does not have pre-determined resistance levels. However, from the lowest resistance point to the highest, there is quite a difficulty range. As a general idea, even on the lowest difficulty setting there is a bit of consistency as the flywheel is fairly heavy. Conversely, when the magnets are as close as possible to the flywheel, the bike simulates a steep climb and will offer quite a challenge even to the most seasoned users.
Last but not least, the bike’s tension system can act as an emergency brake as well. In case you need to stop the flywheel from spinning, you can press on the tension knob. This emergency braking feature is quite necessary as stopping the flywheel from the pedals with your feet is not recommended and can lead to injuries.
Fitness monitor
The Sunny Health & Fitness SF-B1964 indoor cycling bike is equipped with a pretty basic fitness monitor. It 
features an LCD display (without backlight). It tracks time, distance, total distance, speed, calories, RPM, and pulse. Speed and distance are shown in MPH and miles; there is no option for setting them to metric units. The pulse reading function is grip contact only. The unit cannot read your pulse from a wireless transmitter; it can only read your pulse if you hold on to the sensors integrated into the handlebar.
The monitor unit does not have pre-set programs, goal settings, or online connectivity. It only has one button which basically covers two functions. By pressing it repeatedly, you can select the workout metric that you want to view on the display or select the scan mode which automatically rotates all the metrics. You can also press and hold it for a few seconds to reset all the values to zero.
The monitor unit is battery-powered. It requires two AAA batteries which are included. It starts monitoring your workout data when you begin pedaling or when you press the button. It also automatically turns off if it does not detect any activity on the bike for more than four minutes.
Assembly and Maintenance
The main body of the Sunny SF-B1964 comes pre-assembled. The flywheel, the belt, the crankset, and the magnetic brake are already installed. You only have to attach the two base stabilizers, the pedals, the seat, the handlebars, and the fitness monitor. This shouldn’t take more than 40 minutes of your time. All the necessary tools are included and the manual provides clear, step-by-step assembly instructions.
For maintenance, you only have to keep the bike clean. Since it has a belt drive system, the drivetrain does not require lubrication. Also, since the brake is magnetic, it doesn’t require lubrication or replacement either. So, other than keeping the bike clean, you only have to check for loose bolts and parts from time to time.
The Pros
- Sturdy construction – can support users up to 275 lbs;
- Small footprint;
- Four-way adjustable seat;
- Contoured saddle with a median cutout for improved breathability;
- Multi-grip handlebar with aero grips;
- Pulse sensors integrated into the side grips of the handlebar;
- Solid crankset, can support just about any spin workout;
- Metallic pedals with toe cages and standard threads;
- Frictionless magnetic resistance for a smooth pedaling motion;
- Smooth and quiet belt drive;
- Exercise meter included – it tracks time, distance, total distance, speed, RPM, pulse, and calories burned;
- Little maintenance required;
- Device holder included;
- Bottle holder included;
- Dumbbell holder included;
- Easy to assemble;
- All the assembly tools are included;
- Excellent warranty.
The Cons
- No backlight on the fitness monitor;
- No goal functions on the fitness monitor;
- No online connectivity.
Summary
The Sunny Health & Fitness Pro II SF-B1964 is an indoor cycling bike designed for home use. It is equipped with a 40-lb. flywheel, a manual magnetic resistance system, a heavy-duty crankset with caged metallic pedals, and a basic fitness monitor. It’s a pretty sturdy bike, rated for users up to 275 lbs. It’s designed for spin workouts, great for high-intensity cardio training, intervals, muscle toning, stamina development, and weight loss.