The Sunny Health & fitness SF-B1709 Magnetic Rear Belt Drive Indoor Cycling Bike has a distinctive look that catches the eye. (And a long name too!)
With the flywheel at the back, it shares that look with the Keiser M3i that it emulates in a number of ways.
The look and the features do make it appear to be a good possibility to own to get a good indoor cycling workout and training in the home, whether that is following along to classes on an app or video or your own plan.
The belt drive, magnetic resistance are good benefits but the light flywheel does give make you wonder if it can deliver especially as there is much talk about the benefits of a heavy flywheel (including here on this blog).
Can it really be a good alternative to the more expensive Keiser M3i? Read below for the complete review.
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Sturdiness
The bike has a steel frame and stabilizer bars to prevent any rocking or wobbling at any level of intensity in and out of the saddle.
The bike should be stable on all floor surfaces including many carpets. The only issue you may have on carpet is if you have a deep pile and the stabilizer barscan’t settle properly. An exercise mat may help a little in this situation but you may need a plywood sheet if your carpet is very plush.
To help prevent wobbling on an uneven floor there are 4 levelers – one at the end of the stabilizer bars. You can turn them balance out the bike to take account of any minor unevenness in the floor and keep your workout experience steady.
Customers who have used it for six months say they’ve not had any issues and all working as expected with very little in the way of creaks or squeaks (if any).
It has an ok limited warranty of 3 years on the frame and 180 days on the other component and parts.
Sunny Health & Fitness SF-B1709 Magnetic Rear Belt Drive Indoor Cycling Bike Adjustability
The seat and handlebars can be adjusted up and down as well as backwards and forwards to help set an optimum size for the user.
It provides many options to accommodate a range different body type and sizes so they can set the bike to the the most comfortable and effective position for their workouts.
The adjustments cater for those with an inseam between 28 ins and 39 ins (measure from top inside thigh to sole of foot. People between 5 ft and 6 ft 3 ins seem to not have an issue getting an effective fit where leg is slightly bent at full extension.
To fit different upper body lengths and position over the pedals you can have the seat in a range of 25.5 ins to 30 ins away from the handlebars.
Making the adjustments is easy to do and there are markings on the poles to help return to your preferred setting if someone has changed the positioning of seat or handlebars.
It takes moments to do the adjustments so shouldn’t be seen as a barrier to working out if you need to change or for people to share the bike.
The height adjustments use knobs and pull pins to keep in place so they won’t move when tightened in place. You are restricted as to where the pre-set holes that are about an inch apart. The horizontal positioning is similar but you can position the handlebars and seat to where you want without the restriction of pre-set holes.
You loosen the knobs and position in place and then tighten to hold the handlebars and seat in place.
Sunny Health & Fitness SF-B1709 Magnetic Rear Belt Drive Indoor Cycling Bike Resistance
The exercise bike’s magnetic resistance is controlled with a lever on the support post a few inches above the frame. It is a little higher up than the more traditional tension knob on indoor cycling bikes but lower down than the one on the Keiser M3i.
Most people find it easy to use and at a reasonable height for changing while exercising as they would a tension knob.
It has 13 different levels that you can tell you have moved up or down one with a soft click as you move to the next level. The transition between levels is smooth but unlike other bikes you can’t set it at your own personal preference but most find the levels available give them the variation and setting needed to get the benefits without feeling restricted.
Unfortunately, the resistance levels aren’t marked or displayed on the included monitor. You need to estimate your level when following along to a workout.
You can do this by feel or by the position of the resistance level and/or by counting the number of clicks from the lowest setting or the highest setting to get to the level you want. Halfway is going to be somewhere between 6 and 7 and you’ll have to choose 6 or 7.
The click counting is a good way to work out how hard you should be working when following along to an online class or App like Peloton Digital.
Most people seem to find the range of resistance meets their requirements with it being like a flat road as the lower levels and tough at the top end. However, if you are a seasoned cyclist used to tough hill climbs you may find it isn’t tough enough for the challenge you want.
Drive type
The bike comes with a belt drive that helps to provide a smooth and quiet exercise experience. It gives a consistent feel but you do miss some of the outdoor experience that a chain drive can provide.
It also should require very little maintenance especially when compared to a chain drive.
This along with the magnetic resistance allows you to just get on the bike without having to concern yourself with making adjustments or lubricating and in the case of resistance there is no need to replace pads as there is no wear and tear.
This bike is unusual in that the flywheel only weighs 7.36 lbs and made of aluminum, you normally expect them to be around 40 lbs to have the momentum (inertia) to help pull the pedals around and give you a natural feel to the pedaling.
A general rule is that a heavy flywheel is needed for a fluid natural pedaling experience. It is the weight of the wheel has inertia once it has got going which helps pull the pedals through the motion and help to prevent an up pedaing down motion like a stepper that can add impact to the joints.
This set up is a similarity with the Keiser M3i using the same design to provide a smooth ride and stop choppiness you might think you’d get.
With this indoor cycle bike that inertia or momentum is provided by the flywheel turning quicker due to the “gearing ratio” with the pedal drive being bigger and the flywheel drive being smaller. This provides the same force as the heavier flywheels the pedals keep turning.
Most people who ride it like it and say it is smooth. They also comment that it easier on the joints when trying to stop than indoor bikes with heavier flywheels.
You can’t coast or freewheel on the bike as it has a fixed gear which is normal for this style of exercise bike. When the pedals are moving so is the flywheel and vice versa. When you want to get off the bike you can stop the pedals by slowing them or using the resistance lever as a brake by pushing down on it, so you don’t end up get a whack on the back of the legs from the pedals.
The flywheel at the back of the bike gives it a distinctive look and also has the advantage that it is placed out of the way of the sweat zone so it and its’ parts should not be as likely to be damaged by the corrosive effects of sweat as other bikes with the flywheel at the front.
Pedals
The bike comes with dual pedals with toe cages on one side and SPD clip-in on the other side. This allows the bike to be used by people with specialist shoes with SPD cleats and those with athletic shoes catering for those with a variety of interests.
It also allows you, if you want to progress from athletic shoes to specialist shoes without having to buy and fit pedals.
The advantage of the clip-in shoes is that you get a better connection to the bike and can get a more effective cycling motion and workout.
The stock pedals (some more experienced users are underwhelmed by them) can be changed for other pedals if you prefer models that have a standard bike fit.
Having said that many find the pedals good enough for them to get the cardio exercise they want in and out of the saddle.
Comfort
Seat The seat size is a wider 8 ins by 10.5 ins by 2 ins, and cushioned to improve comfort. It does seem to be a good fit for many that use the bike on a regular basis.
As with any exercise bike seat not everyone is going to find it suits their sit bones. To help with this you can try getting used to it – a suggested method is that after 10 minutes of sitting you get up off the seat by standing on the pedals for a short period of time.
However, that may not be enough and to help with that you can try padded bike shorts or a gel seat cover to add more comfort to prevent the pain feeling or numbness.
Or, you can replace the seat with a more comfortable option, just check that it has the same type of attachment fittings underneath the seat. There is a wide range of choice.
Handlebars The handlebars are covered to improve grip as well as comfort. Your hands shouldn’t slip or blister when wet.
There is a wide range of hand positions including aero and drop bars to cater for many riding styles, workouts and grips to get the most out of a workout session. Drop bars are not common for indoor cycling bikes so it is good to see another option for those that want this for their indoor training.
It seems there had been a problem with the handlebars being off centre. Some reviews noted them as being crooked enough to affect their exercising. This seems it may have been an issue with earlier production runs, it doesn’t appear to be the same issue with later bikes.
The hand pulse sensors are on the outside bars in a convenient position and won’t interfere with your grips, of course when they are not gripped the sensors don’t work.
Dirt and CleaningThis bike is not likely to add a big cleaning chore to your schedule. It is good to clean it down with a damp cloth to keep it free from dust build up and being damaged by sweat which is very corrosive.
It is sweat that is likely to be the biggest issue with it dripping on to the bike and floor.
Depending on how much you sweat (if you are like me it is a lot) you may want to buy an exercise bike mat to protect your floor from it.
NoiseThe bike is very quiet with the magnetic resistance being silent as there are no touching parts and the belt drive being very quiet.
You should be able to exercise when you want and not disturb others or wake them if sleeping in another room. You may even be able to exercise in the same room as someone sleeping depending on how light they sleep. It allows you to workout when you want.
If in an apartment your neighbors should have no idea you are on your exercise bike even if they are below you.
To be doubly sure an exercise bike mat can help absorb vibration and noise.
NoiseThe bike is very quiet with the magnetic resistance being silent as there are no touching parts and the belt drive being very quiet.
You should be able to exercise when you want and not disturb others or wake them if sleeping in another room. You may even be able to exercise in the same room as someone sleeping depending on how light they sleep. It allows you to workout when you want.
If in an apartment your neighbors should have no idea you are on your exercise bike even if they are below you.
To be doubly sure an exercise bike mat can help absorb vibration and noise.
Storage
The bike will need an area of 53.2 ins by 23.6 ins when not in use. It does make it a little large for most closets. It could be stored against a wall or other area out of the way if you don’t have the space to keep it out when not in use, as you might not want it in the middle of your living area when not being used.
To help with moving it around it has two small transport wheels at the front of the bike that it can be tipped on to that hold most of the 89.3 lbs weight of the bike. This leaves you to roll and navigate the bike to where you want to put the bike.
One person can do this but you do need to be careful with the balancing and not to knock anything when turning corners or avoiding furniture.
The wheels should work on most surfaces other than deeper carpets where they may jam up.
It should really be stored inside out of the elements, such as rain etc, will likely shorten the life of the bike as it isn’t designed for outdoors.
Assembly
The bike comes with some assembly required. Most of the bike has been put together before it reaches you.
The assembly required can take you up to an hour or so. It can take some time to unpack the bike as it is well packaged.
The instructions and tools needed for the job are included.
The assembly is easier than most kitset furniture with 6 steps to add the pedals, stabilizer bars, seat, handlebars, support posts and monitor to the bike. The frame, flywheel and more are already put together.
The instructions include an exploded diagram and parts list at the front of it which can be ignored as it has many more parts than you need to be concerned with. It can be off putting but isn’t needed for assembly.
The step that does need a little care are attaching the seat to the tube to prevent it coming loose. Some people have mentioned you may need to squint or need a magnifying glass to see the diagrams that are included with each step.
Most people do say they find the assembly easy to do.
It is advised that two people be involved in putting it together due to the weight – the shipping weight is 103.84 lbs. However, people successfully complete the installation of the parts by themselves – I think the most important part may be at the beginning when moving the packaged bike and then getting the stabilizer bars installed due to the weight of the bike.
Sunny Health & Fitness SF-B1709 Magnetic Rear Belt Drive Indoor Cycling BikeConsole
The console is situated at the front of the handlebars in a good position to see when in good light but you may struggle to see it properly when light is dim.
It is a basic monitor giving you calories, speed, time, distance, cadence (RPM) and pulse rate.
The screen is split into 4 sections:
Top section is a graphic bar chart for when you use the race functionality where you can set a target for cadence, time or distance and see how you are get along. For time and distance the meter will beep when you finished.
The next section shows speed and cadence, next displays distance, calories and pulse, and 4th section has time.
The buttons below allow you to set targets for time, distance and calories, the mode allows you to choose the values being displayed, reset allows you to clear the metrics except total distance which only clears when the batteries are removed.
The metrics that are calculated estimates are calories, speed and distance. Unfortunately most don’t think that close too actual especially the calories. There is not an option to recalibrate them. Although they are fine for comparing results from one workout to the next even though they don’t take resistance in to account.
Distance and speed can be set to kilometers or miles.
Time, cadence and pulse are actual numbers, however I do have a concern with the accuracy and usage of hand pulse sensors.
I do like being able to monitor heart rate to measure effort and heart rate zone training can be very effective.
I prefer using a chest heart rate strap and the arm bands can be effective too.
Pulse sensors can be erratic and not always provide an accurate enough heart rate number due to problems with the sensors. This is a common problem with these type of sensors. Your hands can be too dry, too wet or you’re not gripping them hard enough.
This leads on to the other issue with them. You need to be gripping both of the sensors to have your heart rate be measured. If you want to see this measure to monitor your levels you can only have your hands in the one position unless you are okay with seeing it from time to time just as a quick check.
The RPM measure can help to keep you on track whether following your own “thing” or if you are following a class online or an App. I find it helps me keep the pedal rate where its needed as I struggle with using rhythm or following the instructor,
The console does not have bluetooth capability. Therefore, it won’t work with any Apps for feedback as you exercise or for a record of your workout. You’ll need to record or update any Apps manually.
Of course you can use with indoor cycling Apps as well as others as you would a video.
If you are going to use with Apps like Peloton Digital App or Les Mills you have the cadence read out on the monitor to help keep you on track and you can try the pulse sensors if following a heart rate zone class.
It is possible to add sensors to the bike and a heart rate strap to have your readings appear on an App to put everything in one place
Unfortunately, for resistance level you need to estimate this either from feel or position of tension lever and it is something most people find they get used to it quickly. There isn’t sensor you can add for this.
The console needs 2 AAA batteries to work and these are included. You don’t need the console to be working to use the bike.
Dimensions
The weight and dimensions of the bike are:
Height 54.3 ins
Width 23.6 ins
Length 53.2 ins
Flywheel weight 7.36 lbs
Bike Weight 89.3 lbs
Max User Weight 300 lbs
Accessories
A further accessory the bike comes with is a wire frame bottle holder that is between the handlebars which does put it in easier reach than on the side of the bike that Sunny normally positions them.
The bike is missing a tablet holder or a place to rest on the handlebars – some people have found they can rest a tablet or ipad on the handlebars propped against the monitor but it isn’t safest idea, although no-one seems to had a problem with their device falling off the bike.
I wouldn’t do it myself and I’d get a tablet holder that can be bought separately and attached to the handlebars.
If you want to use hand weights as part of your workout there isn’t a place to put them and you may need to either put them on the floor near you or have a shelf close by.
Pros
- Dual pedals – SPD/Toe cages
- Console that measures RPM
- Includes drop bars
- Easy to assemble
- Low maintenance
- Magnetic resistance and belt drive
- Quiet bike
- Can be an affordable alternative to Keiser M3 or M3i
- Water bottle holder
- Lighter than many other indoor cycles
- Transport wheels
- Rear flywheel protects it from damage from sweat
- Not a continuous/incremental magnetic resistance adjustment
- Console doesn’t measure power or resistance level
- Console doesn’t have bluetooth to work with Apps
- Nowhere to put hand weights
- Concerns over accuracy of some of the metrics
- Nowhere to put phone or tablet
Cons
Consumer Ratings
In most customer reviews they say they like the bike. They feel it compares well with the Keiser M3i considering the more affordable price.
It isn’t as good, as you’d expect, from the price differential but feel they get a good indoor cycle and get most of the benefits too.
There was an issue with the handlebars not being straight and this is mentioned by some customer earlier but it does appear not be an issue now.
Sunny appear to be not as responsive as they have been in the past but this is probably due to the current circumstances.
On the whole they are positive and get an indoor cycling bike that meets their expectations and get a good problem free cardio workout.
Price
The Sunny Health & Fitness SF-B1709 Magnetic Rear Belt Drive Indoor Cycling Bike is an affordable exercise bike when compared to the Keiser M3i which shares some of the styling and functions.
It includes the light rear situated aluminum flywheel, dual pedals, belt drive and magnetic resistance controlled by lever. It is these features that help explain it being one of the more expensive Sunny bikes on the market.
It can be a good idea to check sites on web in current situation, however, Amazon is often a good place to check out the bike and buy.
Review Summary
This indoor cycling bike has a number of good features and does a good job of delivering on being similar to the Keiser M3 & M3i. All at a more affordable price.
It does provide some metrics via its console in particular RPM which can help to follow indoor cycling classes. However, the console is definitely not on a par with the more expensive bike it is modeled on. It provides only the basics.
If you want full data and some compatibility with Apps then it won’t satisfy on its own although you can add sensors and other monitors retrospectively (not specifically designed for the bike).
It does provide much the same cardio benefits of indoor cyclingwith a smooth and consistent ride that is designed to accommodate a range of body type, abilities and fitness goals.
I think it looks good and delivers on the promise of being a step up from a starter bike without the price of the premium indoor cycling bikes.