| Unit | Size | Supported weight | Resistance | Console | Warranty |
|---|---|---|---|---|---|
Circuit Fitness AMZ-150BK Check Discounted Price | L:33" W:16" H:45.5" | 250 lbs | Magnetic, 8 levels | Time, Speed, Distance, Odometer Calories, Pulse, SCAN | 2 years limited |
The Circuit Fitness AMZ-150BK exercise bike can be compared in terms of features with the ProGear 225, or the XTERRA Fitness FB150. It has a slightly different console unit, though, with an integrated tablet holder. Also, the console has target settings for some of the workout metrics; the aforementioned bikes don’t have this feature.
Key Features and Specifications
- Assembled dimensions: 33L x 16W x 45.5H inches (84L x 41W x 116H cm)
- Assembled weight: 34 lbs (15.4 kg)
- Supported weight: 250 lbs (113 kg)
- Seat: 2-way adjustable
- Pedals: With straps
- Resistance: Magnetic, 8 levels
- Fitness meter: Time, distance, total distance, speed, calories, pulse, goals
- Warranty: 2 years limited
Frame construction
The Circuit Fitness AMZ-150BK upright bike features a folding X-type frame. It consists of two main 
pieces that are connected in the middle. The frame piece with the handlebar and console consists of two long parallel bars, while the frame piece with the seat and the drive system is shorter and goes through the two parallel bars.
The bike’s frame is steel-made, with the exception of the drive system casing which is made of durable ABS plastic. Also, the bike doesn’t have the upright stopper bar like the Exerpeutic Gold 575 XLS, for example. Therefore, it only has a weight capacity of 250 lbs (113 kg).
All the steel parts in the bike’s construction are coated with a rust-resistant paint finish. The color used is gray, this being the only color available for this bike.
Like most other similar exercise bikes, the Circuit Fitness AMZ-150BK is a fairly small fitness machine. With all the parts assembled and the frame fully set up, its footprint is only 33″ (84 cm) long, and 16″ (41 cm) wide. Also, its highest point is 45.5″ (116 cm).
As we’ve mentioned above, the bike’s frame is foldable. Its two main pieces fold from the middle which reduces the bike’s footprint to 17.5″L x 16″W (44 x 41 cm), while its height becomes approx. 51.5″ (131 cm).
The bike is fairly light. With all the parts assembled, it weighs approx. 34 lbs (15.4 kg). This being said, it can be carried and assembled by only one person. Plus, its portability is improved by the two small wheels integrated into its front base bar.
Seat and handlebars
The Circuit Fitness AMZ-150BK is equipped with a large seat for extra comfort. The saddle itself is 
approx. 15″ (38 cm) wide, and 11″ (28 cm) long, so it provides plenty of contact surface. It integrates a thick (~2″) layer of foam padding and features a durable vinyl top cover.
The seat is two-way adjustable (up, down). Its upright post has 7 adjustment holes. The bike is designed for users with an inseam height between 32″ and 36″ (81 – 92 cm). This being said, it should accommodate users between 5’2″ and 6’4″ (157 – 193 cm) with no problem.
Its important to mention that the seat post features a triangular metallic plate at the top to which the saddle attaches via three bolts. Therefore, a saddle with the exact specs may not be that easy to find, in case you will ever need/want to replace the original one.
The bike’s handlebar offers three grip possibilities, these being climbing grip, standard grip, and close grip. The handlebar doesn’t adjust; it attaches to the main frame via bolts. Its grips are fully covered by a layer of rubber foam material for extra comfort.
The side grips of the handlebar integrate pulse sensors. Not all upright bikes have this feature, so it’s a plus. Needless to say, the included console has a pulse tracking function as well.
Drive and resistance
The Circuit Fitness AMZ-150BK is equipped with a manual magnetic resistance system. This being said, 
there’s no friction between the resistance elements, and the pedaling motion is very smooth and quiet. It also means that you won’t need a power adapter for it or an external power source. But on the other hand, the bike cannot automatically adjust the resistance.
The bike’s resistance system consists of a magnetic brake that is connected to the tension knob of the bike through a PVC-sheathed steel cable. By turning the knob clockwise, the brake moves closer to the internal flywheel increasing the resistance.
The bike makes available 8 distinct levels of resistance. Each level is marked on the tension knob. The first levels deliver a light tension, while the top, 7-8 levels give you the possibility to undergo a more intense cardio training. But as a general idea, this exercise bike is not exactly meant for highly intense cardio workouts.
Since it’s a light exercise bike, its internal flywheel is not extremely heavy as it is the case for spin bikes. Its exact weight is not specified, but similar other models have flywheels between 3 – 5 lbs (1.3 – 2.2 kg), so this should give you an idea of the bike’s flywheel weight. The flywheel is balanced, designed to provide a steady, low-impact motion. It is also bi-directional; in other words, you can pedal backwards but you cannot free-wheel (or coast) on this exercise bike as it is possible for a road bike.
The bike is equipped with a belt drive system. This type of drivetrain comes with several advantages. First of all, you don’t have to take the drive unit apart to lubricate the belt. Second of all, the belt generates less vibration than a chain. And third of all, the pedaling motion is very smooth and quiet.
The bike features a pretty sturdy crankset, but just like any other upright bike, it is not meant for standing up on the pedals, or spin workouts. The included pedals are weighted and have a non-slip surface. They’re also equipped with adjustable straps.
Console
The console included with the Circuit Fitness AMZ-150BK upright bike is basically a fitness meter only. It
doesn’t have preset programs or online connectivity. It only tracks the most important workout metrics, including time, distance, total distance, speed, calories, and pulse. Speed and distance are shown in English units (mph, miles) only. There is no option for metric units. Also, the unit is not telemetric. This means it can only read your pulse if you hold on to the integrated sensors. It cannot communicate with a wireless HR chest strap.
Although the console unit does not have workout programs, it does have target settings for time, distance, calories, and pulse. If a target is set for time, distance, or calories, the console will countdown from the selected value to zero, and notify you when you complete your goal. If a target is selected for pulse, the unit will notify you when you reach the desired pulse value.
The console is very easy to use. Its buttons are Mode, Set, and Reset. The Mode button allows you to scroll through the workout metrics and select the one you want to view on the display. It also allows you to select the Scan Mode which rotates all the metrics, showing each one for 6 seconds. The Set button allows the selection of targets for time, distance, calories, and pulse. And finally, the Reset button clears all the values on the meter to zero, except the odometer (total distance traveled).
The unit is battery-powered. It requires two AAA-type batteries which are not included. It starts up when you begin pedaling, but it also automatically turns off after a few minutes of inactivity on the bike.
One last notable console feature is the integrated tablet holder. This consists of a plastic support placed at the back of the unit, with a non-slip portion in the middle, which can support any tablet. However, the console does not have a USB port or an AUX port to connect your tablet or smartphone to it.
Assembly and Maintenance
The two main pieces of the bike come pre-assembled, with all the drive and resistance elements assembled as well. Therefore, you only need to connect the two base bars, the seat post, the saddle, the pedals, and the handlebar with the console. This shouldn’t take more than 30-40 minutes. The task if straightforward and the manual provides very clear assembly instructions. Also, all the necessary tools for assembly are included.
Maintenance doesn’t require much. All the internal components are pre-lubricated from the factory, and since the bike has a belt drive system, it doesn’t require any lubrication. Thus, for maintenance, all you have to do is wipe the dust from the frame and periodically check for loose parts and bolts.
The Pros
- Fairly sturdy frame – can support users up to 250 lbs;
- Transport wheels included;
- Small footprint when fully assembled;
- Foldable, great for a small apartment;
- Large, padded seat for extra comfort;
- Multi-grip handlebar with pulse sensors;
- Weighted pedals with straps;
- Narrow Q-Factor for zero lateral stress on the knees and ankles;
- Smooth and quiet operation;
- Fitness meter included – it tracks time, distance, odometer, speed, calories, and pulse;
- Goal selection function for time, distance, calories, and pulse;
- Tablet holder included;
- Easy to assemble;
- Little maintenance required.
The Cons
- No backlight on the console display;
- The batteries for the console are not included.
Summary
The Circuit Fitness AMZ-150BK is a foldable magnetic upright bike designed for home use. It features a quiet belt drive system, 8 levels of manual magnetic resistance, and a fitness meter that can track time, distance, speed, calories, and pulse. It’s a bike for light to medium-intensity cardio training, muscle toning, stamina development, and weight loss. In all, it’s a fairly decent exercise bike and affordable as well.