| Unit | Size | Supported weight | Drive | Resistance | Fitness monitor |
|---|---|---|---|---|---|
Sunny SF-E3908 Check Discounted Price | L:25.2" W:18" H:10.6" | 220 lbs | Belt | Manual magnetic, 8 levels | Time, Distance, Speed, Calories, Scan |
The Sunny SF-E3908 is one of the elliptical trainers released by Sunny Health & Fitness in 2020. It’s pretty similar to the Sunny SF-E3872 that we’ve already covered here, but it has a sturdier build. It’s not only an under-desk elliptical, it can also be used while standing up.
Key Features and Specifications
- Assembled dimensions: 25.2L x 18W x 10.6H inches (64L x 46W x 27H cm)
- Assembled weight: 25.4 lbs (11.5 kg)
- Weight capacity: 220 lbs (100 kg)
- Stride length: 7 inches (17.7 cm)
- Drive: Belt
- Resistance: Manual magnetic, 8 levels
- Fitness meter: Time, distance, speed, calories, scan
- Warranty: Frame 1 year / Parts 180 days
Frame construction
The Sunny Health & Fitness SF-E3908 elliptical trainer is constructed on a steel frame with an ABS
casing for the drive and resistance elements. The frame is coated with a corrosion-resistant paint finish black in color, this being the only color available for this machine. However, as opposed to the older SF-3872 model, the ABS casing is gray, not white.
Similar to other under-desk elliptical trainers, the Sunny SF-E3908 is not a large fitness machine. With all the parts assembled, it is approx. 25.2″ (64 cm) long, and 18″ (46 cm) wide. Therefore, it should fit under most desks. However, if used in a standing position, a clearance of at least two feet all around it is recommended.
The trainer is not too heavy. With all the parts assembled, it weighs only 25.4 lbs (11.5 kg). This being said, the packaged unit can easily be carried by only one person. Also, once the unit is assembled and ready to use, it’s easy to carry as the plastic casing of the drive system features a handle at the top.
Pedal construction, stride, and elliptical path
The Sunny Health & Fitness SF-E3908 elliptical trainer is equipped with a set of solid pedals. As we’ve 
mentioned above, as opposed to the older model, this one can be used while standing up as well, not only when seated. It has a maximum user weight capacity of 220 lbs (100 kg) which is not bad for a small unit like this.
The pedal trays are made of durable thermoplastic material. They have a ribbed surface and heel guards for superior foot stability. They are non-adjustable but they’re large enough to accommodate footwear of all sizes. The pedal bases are made of steel tubing. They connect to the machine’s crank arms on one end and rest on two large silicone wheels on the other.
The machine features an elliptical path slightly inclined forward. Therefore, if you will be using it in a standing position, the pedaling motion feels like descending on a soft path. It does not have a very long stride, though. Its stride is only 7″ (17.7 cm) so the pedaling motion is closer to the one of a stepper than the one of an elliptical. So, even though it does not promote a long range of motion, it still provides an excellent workout for the thighs, glutes, and calves.
The trainer does not have an incline system. Therefore, the length of the stride or the angle of the elliptical path are non-adjustable. It’s not recommended to place it on a slanted surface even if used while seated.
The machine’s pedal height is 10″ (25 cm) above the floor level. This being said, it is recommended to use this Sunny elliptical in a room with a ceiling that is at least 15″ (38 cm) higher than your own height, if you will be using it while standing. Conversely, if you’re going to use it under a desk, the desktop board should be at least 11″-12″ (27-30 cm) above your knees when seated.
Drive system
The Sunny SF-E3908 under-desk elliptical machine is equipped with a belt drive system. It integrates a J300
poly-v belt designed for maximum traction and is highly resistant to abrasion and stretching. As opposed to a chain drive, the belt generates slightly less vibration, so the right is smoother. Also, the belt does not require periodic lubrication.
The unit is equipped with a perimeter-weighted flywheel. Evidently, since it is an under-desk portable elliptical, its flywheel is not too heavy. Its exact weight is not specified, but as a general idea, the older model had a flywheel of approx. 3.5 lbs (1.6 kg), so the one on this unit is probably similar. The perimeter-weighting design is meant to improve inertia. Thus, even though the flywheel is not too heavy, the pedaling motion is pretty smooth and consistent.
The flywheel is bi-directional. This being said, you can pedal both ways. Even more, if you will be using it in a standing position, it is recommended to keep it with the crankset at the back, and the pedal wheels at the front. Conversely, if you will be using it at the desk, it’s best to have the crankset at the front.
The machine’s crankset is pretty durable. It features two solid steel arms, similar to the ones on road bikes. Also, the wheels on the opposite side of the pedals are pretty large. They have a thick silicone layer on the outside to reduce noise and internal bearings for a smooth motion. They roll on two metal plates which are welded to the machine’s frame.
Resistance system
The Sunny Health & Fitness SF-E3908 elliptical trainer is equipped with a manual magnetic resistance 
system. Thus, you don’t need a power adapter for it, or an external power source. However, this also means that the machine does not adjust the speed or the pedal tension automatically.
The unit’s resistance system consists of a small magnetic brake connected to the tension knob on the main unit of the machine. When you turn this knob left or right, the brake changes its angle in relation to the flywheel placing the magnets closer or farther from it. This increases or decreases the pedaling difficulty.
The machine offers 8 distinct difficulty levels. The first level delivers a fairly light pedaling difficulty, great for recovery training, or muscle toning. Conversely, the 8th level of resistance provides considerably more pedal tension for a more intense workout. Plus, if you will be using it while standing up, you will benefit from a considerably more intense burn as you will need extra balance and motion control.
The main advantage of the magnetic resistance system is the lack of internal friction between the brake and the flywheel. This leads to a very smooth and quiet pedaling motion. Also, the brake does not need lubrication and the brake pad never wears out as is the case for a felt brake pad.
Fitness monitor
The Sunny Health & Fitness SF-E3908 under-desk elliptical trainer is equipped with a basic fitness monitor.
It features an LCD display (without backlight) divided into two sub-sections. The top section always shows speed; the bottom section indicates time, distance, and calories burned. The unit does not have a pulse reading function, an RPM function, or a step count function. Speed and distance are shown in English units (MPH and miles); they cannot be set to metric units.
The monitor unit only has one button that covers all of its functions. By pressing it repeatedly, you can change and select the metrics displayed on the bottom section of the monitor. It also has a Scan Mode. When in Scan Mode, the unit rotates all the metrics on the bottom display, showing each one for a few seconds. The button also covers the unit’s reset function. You can press and hold it to clear all the values to zero.
The monitor unit is battery-powered. It requires an LR44 (1.5 V) battery which is included. It begins recording speed, distance, etc. when it detects pedal movement. It also automatically turns off if it does not detect any activity on the machine for approx. 4 minutes.
Assembly and Maintenance
This Sunny Health & Fitness under-desk elliptical trainer comes pre-assembled. You only have to remove it from the box and it’s ready to use. The manual provides fairly decent instructions on how to operate it.
In terms of maintenance, there isn’t much to be done either. The internal parts don’t require any lubrication. However, if the joints of the pedals or the wheels begin to squeak, they may need lubricant. Other than this, you only have to keep the unit clean and keep liquids away from the fitness monitor.
The Pros
- Small footprint, great for apartment use;
- Can be used seated and standing;
- Lifting handle on the main unit of the trainer;
- Lightweight, easy to transport;
- Extra-large pedals with side guards;
- Large silicone wheels on the pedals for reduced noise;
- Zero-friction, magnetic resistance system (8 levels);
- Belt drive system for a smooth and quiet pedaling motion;
- Fitness monitor included – it tracks time, speed, distance, and calories burned;
- Battery for the monitor is included;
- No assembly required;
- Little maintenance required;
- Excellent warranty.
The Cons
- The fitness monitor does not have backlight;
- No RPM function;
- No pulse reading function.
Summary
The Sunny Health & Fitness SF-E3908 is an under-desk elliptical made for home use. It features an 8-level magnetic resistance system, an internal belt drive, a set of large pedals with silicone wheels, and a basic fitness monitor that tracks time, distance, calories, and pulse. It can be used while seated or while standing and has a maximum user weight limit of 220 lbs. In all, it’s a fitness machine designed for light to medium-intensity workouts, muscle toning, stamina development, and weight loss.