I a 73-year-old woman and fractured and dislocated my shoulder on 10/24/25. I was able to assemble this cycle in less than 10 minutes by using a 14mm ratchet. It’s nice and tight, no squeaks or noises. The directions tell you how to screw on the pedals in two places, I.e. the pedal itself and the printed manual. There’s no excuse for screwing it on the wrong way. It doesn’t slip on my rug when I use it for my legs. I put it on my knitting blocking squares to keep it from scooting on my table when I use it for my arms. I bought it because I needed a very basic cycle for my arm therapy. It really helps. It’s just the right size and doesn’t take up a lot of space. I will update if there is a need to, but so far, so good.

So the first thing you should be aware of is that Sunny makes full-size exercise equipment. They are quite well-built and this little unit is no different.
With that said, I bought mine used as an Amazon Warehouse Deal, and had an issue right out the gate–which is why I assume it was returned to Amazon for the Warehouse Deal program in the first place. The pedals could basically move just a few degrees back and forth before they'd get locked up on something internal. I ended up needing to get a crank removal tool to open it up, as case removal is blocked by the cranks on either side.
Immediately upon opening it, I was able to see the issue: the retaining bolt for the magnet arm had backed out and was interfacing with the spokes of one of the internal wheels. After I tightened this down, everything worked great. It also gave me an opportunity to see the insides of this thing.
So looking at the internals on this… I'm glad I got this instead of the $40 friction-based machines scattered all over Amazon. Those things either use a bolt directly on the mechanism, or a strap that you tighten–both vastly inferior to the magnetic system this uses. Basically, YOU are the electromagnet generator, and the dial moves the magnet closer or further from the internal wheel. Friction-free resistance with little to no wear!
For assembly, the instructions aren't too user-friendly, but are VERY detailed. Take your time; there's so few parts to install, you just need to make sure you abide by the 10 warnings about using the correct parts on the correct side. One side is reverse-threaded so that your movement doesn't loosen them. Don't mix them up (and DON'T cross-thread them if it's not going in correctly), torque everything well and you shouldn't have an issue.
Sunny also appears to have parts for everything at the ready, which is great to know. Remember the warranty on the mechanicals is only 6 months (frame is 12 months), so make sure everything is in good shape. This is a mechanical device, so some basic care is still required–treat it like a bicycle. The manual (also available on their site) has a great explosion diagram of all the parts and their names.
Down to use–this thing is great. Extremely quiet and the magnetic resistance system is great. Definitely a noticeable difference between settings, with the higher settings delivering a good challenge; I'm sure everyone who gets will find a range to use. The on-board computer is good for distance and speed, but doesn't interact with the resistance setting, so take the calorie counter with a grain of salt. Just get your heartrate and breathing up, and work up a sweat.
Bottom line: it's great and if you're even looking at this one vs the cheap ones on Amazon, JUST GET THIS ONE!

This is a really good machine, and I recommend it. The action is smooth and it is very quiet – you don't have to make the TV louder if you're using this while watching. The LCD readout is large and easy to read. It is quality all over. I don't know for sure, but my best guess is that this uses the same type of magnetic "mechanism" to provide resistance that the much larger bike machines in gyms do.
Probably more important than any of that for me is that this thing gives a really good workout. I've been using it for the past couple of days at the level 6 (out of 8) setting, and after a half hour of pedaling, I am panting and sweaty. That's what I wanted, and that's what I got. (Thank you, Sunny Health!) Cheaper machines, like the $40 Platinum Fitness PFP2100 Fit Sit Deluxe Folding Pedal Exerciser Leg Machine with Electronic Display, Blue (which I also bought and had to return) just don't provide enough resistance for any kind of workout. They are designed to be for range of motion, but not for any kind of exercising. This machine does give enough resistance for a good solid workout.
However, the one problem this has is that it doesn't have enough "stiction" – meaning that the textured rubber pads on the bottom of the four legs of the machine don't provide enough friction to keep the machine in place. Granted, like I said, I'm using it at a high level of resistance (6), and, according to the machine, I'm pedaling at 22 mph (which I doubt, but whatever). As I workout (with the machine sitting on top of a rug), the machine will slide away from me until I'm practically in a recumbent riding position. I have to put about 25 lbs. of weights distributed over the legs to keep it in place.
The easiest fix would be if the manufacturer took users like me into consideration and put more rubber on the bottom of the feet to keep this thing from moving all over the place. The way it is now, as you can see in the photos, is that the rubber is only about 2 inches wide at the very edges of each leg. The rubber should go completely from side to side underneath. Even with the weight I have on it now – which is all the weight I have in the house! – it still moves slightly as I pedal. I haven't reached level 8 yet – I'll probably need even more weight!
Even with that one correctable flaw, the machine definitely does its job of working me out, and I would not return it. I'm looking forward to using this every night and getting to some very much needed weight loss.

Cycling isn't smooth, but somewhat jerky unless you are going fast.
Easy to put together.
Stable.