Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike Review

The Sunny Health & Fitness SF-B1805 Indoor Cycle Bike comes has a good reputation from a company with a range of well regarded exercise bikes.

This is one of their more expensive bikes although it is still in the mid-range of prices for indoor cycles.

It doesn’t come with a huge amount of extras.

It does have a tablet holder which is useful for viewing fitness apps or other videos.

Instead it has magnetic resistance, belt drive, adjustable seat and handlebars, and a heavy flywheel which all help to provide quality workout routine.

But does it deliver on its reputation and the features and give a quality low impact cardio workout?

In a hurry? >>>


The Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike has a heavy-duty steel frame and stabiliser bars to provide a good solid base for all intensity of workouts. It will support people up to a weight of 300 lbs.

The bike doesn’t wobble when out of the seat or when transitioning. You can concentrate fully on your workout pushing hard with the resistance turned up high. The bike shouldn’t be a distraction or concern.

If your floor is a little uneven there are 4 levelers – one each at the end of the stabilizer bars that can be used to even up the bike and stop the bike from rocking when you use it.

It should be stable on most carpets but you may find it leaving dents from the bike and your weight under the levelers.

The manufacturer warranty is 3 years on the frame and 180 days on other parts. It’s not the best and at this price it would be good to see a longer one.

Most customers feel they have got a bike that is robust and durable and they will get a lot of use out of it. There doesn’t seem to be an issue with longevity reported in reviews.


The bike seat and handlebars have 4 way positioning allowing them to be adjusted backwards/forwards and up/down to provide the most effective and a comfortable position for exercising. Having the right fit can help with the quality of workout and reduce strain.

Within the range of movement you can set the handlebar and seat to just where you want. You are not limited by preset holes. It allows you to get a closer fit. It is important to tighten up fully to prevent slipping.
As they are handles rather than knobs you may find you can’t completely turn them enough to tighten fully. This can be sorted by changing the positioning of the handles so they can be tightened so you should never be left with anything not properly tightened.

To move the handlebars and seat vertically or horizontally you undo the adjustment levers and set to where you want and then tighten back up.

Sunny recommend the bike for people with an inseam from 28 ins to 38 ins. This is not the pants length measure, although it is similar. It is measured from the top if the inner thigh to the bottom of the foot which is a few inches longer.

People from 5ft 2 ins to 6 ft 2 ins seem to have been able to use the bike comfortably but to be sure especially if close to the end of the ranges it would be advisable to measure your inside leg length.

You can use over 6 ft 2ins but depending on leg length you may find you are not getting proper leg extension at the bottom of the pedal stroke. It should be slightly bent to have the most effective workout. If you are taller or have longer legs than recommended our list of bikes here can help.

If leg length is less than 28 ins you will find yourself stretching to reach the pedals. Other choices of bike that may be more appropriate can found here.

Leg length is a better measure than height as people’s leg length varies for people of the same height and genders.

There are markings on the posts making it easier to know where you’ve set it to and return to it if you and other members of your household are using the bike and moving the seat and handlebars.

Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike Resistance

The bike’s magnetic resistance is controlled by a tension knob at the front of the bike above the flywheel. There is a pair of magnet blocks either side of the flywheel that are moved closer to it by turning the knob to right increasing the intensity making it harder to turn the pedals. Turning left moves them away and makes it easier to pedal.

The magnets don’t touch the flywheel so there is no rubbing noise or wear of the pads as you get with felt pads. It is quiet and low maintenance.

The flywheel and the magnet resistance don’t have a guard to prevent sweat from dripping down on them. Although, I like being able to see the magnets work, it would be better for them to have a guard. Sweat can drop on them and is very corrosive, so it will be important to wipe the area down with a damp cloth to keep the them in the best shape.

The top resistance setting doesn’t put the flywheel at a dead stop as you get with friction pads but it is tough. You can be out of the saddle and struggle with keeping the cadence (pedaling stroke/RPM) up. Hardened cyclists may find it lacking a little at the top of the range but for the rest it should be more than enough (if it isn’t then contact Sunny).

It doesn’t come with any measure of the resistance setting. The setting you have the resistance will need to be done by feel and estimate. It’s not uncommon for indoor cycles not to have the resistance measured (see Schwinn IC4 – it is an exception if you want this measure but does cost more and with more extras). Many people find they get the hang of it by listening to the instructor of the class they are following, counting the turns from easiest to hardest and estimating position that feels like cycling on a flat road.

Drive type

The belt drive provides a quiet and consistent experience. You don’t get the clinking or the slight variation that you get with a chain drive as you do with a road bike. As well as being quiet it is low maintenance with none of the lubrication and tightening that is required with a chain.

The bike has a fixed gear which means when flywheel is turning so are the pedals. There is no chance of coasting or freewheeling – your feet are turning. It is important to being the pedals to a stop by gently slowing down or if in an emergency push down hard on the resistance knob to bring them and the flywheel to a stop, otherwise you may injure yourself with a pedal hitting you in the back or front of your leg. It can be a very painful experience.

The 44 lbs flywheel gives the momentum to provide a more consistent pedaling experience especially at higher resistance levels as it prevents the pedals slowing down too much to help promote a more fluid ride.

You won’t get the same up/down motion you might have with lighter flywheels. With the heavier flywheel when you are at the top and bottom of the pedal stroke you’re not pushing and pulling with the feet the weight of the wheel helps to pull them round.


The steel pedals come with cages with an adjustable strap. They are designed to be used with athletic or similar shoes. You slip your feet into the cages and tighten the strap to give you a secure platform to cycle to prevent feet from moving and slipping.

If you want a better connection and more effective workout experience you can swap the pedals out for SPD type pedals, to allow you to clip in. The thread pedal is 9/16 ins.

You don’t need to swap the pedal to get many of the benefits from working out.

You change anytime you want to get the better connection which some people do as they progress.

The q factor is 182 mm (7.16 ins) which is the measure of the distance between the inside of the pedals (how wide apart your feet are). The narrower this is the more alignment is possible for hips, knees and legs. This results in less strain on joints. This bike’s q-factor is on the narrower side for indoor cycling bike so you should enjoy a more effective workout with better leg alignment.


Seat It is a larger seat with dimensions of 10  ins by 8 ins by 3 ins, shaped and padded for comfort. It doesn’t seem to get a lot of complaints from people using it.

It would appear Sunny may have learned something about bike seat comfort. They did seem to like to put on seats that had a high percentage of people finding them very hard on the sit bones – more than you’d expect even with the bad reputation of bike seats.

Having said that, there is not a universal acceptance on this. This is to be expected comfort when the sit bones are involved, it’s an area that is very much a personal thing.

So, you may find it uncomfortable, especially if you’ve not been on a bike for awhile. It may just be a matter of getting used to sitting on the seat. To help with the process it is advised to give the sit bones a break by being out of the saddle by standing on the pedals every 10 minutes or so.

In addition you can try a gel seat cover and/or padded bike shorts. If that doesn’t work it is possible to replace the bike seat with other seats that have the same standard bike fit that the Sunny bike comes with.

As with a road bike it is possible to change the tilt and orientation of the bike by undoing the nuts underneath it to get it more comfortably positioned and then tightened up to hold in place.

Handlebars The handlebars are covered to sweat-resistant and prevent your hands from slipping when they get sweaty. It provides a more comfortable grip. The shape of the handlebars give plenty of choice of hand positions with the ability to change your grip to follow along to spinning and other workout classes.

The handlebar thickness is 1 1/3 ins giving a good size for most to grip.

Noise It is a very quiet bike. You may hear a slight sound from the wheel but it shouldn’t be enough to bother you or anyone else. This allows you to use it while watching TV or listening to music without having it up too loud. If there are others in the room they won’t find it annoys them while they watch a program etc.

However, your heavy breathing might annoy when you are pushing yourself hard.

Some have found it quiet enough to use it while their spouse is sleeping in the same room. I probably could sleep through this but I’m not sure I’d risk using the bike with my wife asleep. Another room would be fine but not the same room.

When using it a different room you won’t disturb others at any time of the day or night when you get a chance. If you have young children you could do it while they nap during the day (if you are lucky enough that they take a nap).

There isn’t the pounding that you get with treadmills (or the impact on the joints) allowing it to be used in apartments without disturbing your neighbors even when upstairs. You may want to put it on a exercise mat to prevent any possible transmission of vibration.

Dirt and Cleaning The Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike won’t be adding a lot of dirt and dust to your house.

The biggest mess could well be sweat. This should be wiped down on a regular basis with a damp cloth to keep it performing at its best. You may want to put the bike on a mat to protect your floor or carpet from sweat and the bike moving around


The bike doesn’t fold up. It will need an area of 48 by 23 ins for storage. It looks smart so it’s not an eyesore if you do have to leave it out in a room.

It is heavy, weighing in at 125.7 lbs. To help with moving it there are 2 small wheels (they have been described as looking like roller blade wheels in one review) that you can tip the bike on to when you want to move it around. They hold most of the weight leaving you to navigate the bike to where you want it to go.

It can be unwieldy as you move it and you do need to be careful as you go round corners or furniture.

The wheels work best on hard surfaces and should be fine on carpet except for those with a deeper pile where they may jam and you find yourself having to drag rather than roll.

Due to the weight you probably don’t want to be moving it up or down the stairs on your own and even with two of you care will be needed.


The bike arrives partly assembled. The shipping weight is 139 lbs. The weight and packaging can often be the biggest issue – moving it to where you want to assemble and getting it out of the packing.

It is fairly straightforward to complete the assembly of the bike. Most people can complete it within an hour. The manufacturer recommends 2 people to complete it. It is heavy and particularly when adding the stabilizer bars it is much easier having a second pair of hands to hold the frame in place.

You are required to install the pedals, stabilizer bars, support posts, seat and handlebars to the frame and drive. Much of the hardware is pre-installed making it easier to know which bolt goes where.

The tools needed for the assembly and instructions are included.

The instructions aren’t the clearest but are adequate for the job. Also, for some reason there is a full exploded diagram of the parts of the bike which could make you have second thoughts about putting it together if you view before you see what is required. It has all the parts listed and shown for reference purposes only not for assembling.

For most there shouldn’t be a need for the assembly service.

Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike Console

The bike doesn’t come with a display for measuring or keeping track of your workout. Some people may like this lack, seeing the measures as an unnecessary distraction to a good workout. (I’m not in that crowd.)

If, like me, you’re not that way inclined then there are solutions to the problem of console (or lack thereof).

The most common measure people want is cadence (RPM) (other than time). This can be added by attaching a bike cadence sensor to the pedal crank and monitoring with an App on your phone or tablet etc.. You can add speed and distance with a small bike sensor- although a little more fiddly as it is designed for a bike wheel not a flywheel and heart rate with a strap. (If you do add the diameter of the wheel has been measured at 16.5 ins.)

If you are looking at the bike to use with the Peloton Digital App this is what most do – the cadence sensor. You can read more about the different sensor and consoles that can be added here. The most popular sensor is the Wahoo cadence sensor to help keep in time with the Peloton class or other classes and videos.

If you do want to use with Peloton you can use it as is but there are some items that may provide a better experience including the sensors above, SPD pedals, dumbbells and more.

You can read about what can be added for Peloton in more detail here.

They aren’t critical and you’ll get much of the benefit of classes from Peleton or other workouts like Les Mills without them, but they can enhance the experience and provide benefits with motivation and tracking etc.


The dimensions and weight of the bike are:

Height 45 ins
Weight 23 ins
Length 48 ins

Flywheel Weight 44 lbs
Bike Weight 125.7 lbs
Max User Weight 300 lbs

Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike Accessories

The bike doesn’t come with a great number of extras. The 2 it comes with are useful for taking on liquid or watching video:

Water bottle holder – this is on the right had fork of the bike. The positioning is by the flywheel which means you may find yourself stretching more than you want to take on water while you workout.

Media device holder This is a shelf between the inner handlebars. It is tilted towards you and you lay your tablet or phone on it to watch a video or binge watch a TV series or follow along to a workout video or fitness App (e.g. Peloton).

It fits devices 11 ins (W) by 8 ins (H). As you place the device on the holder the thickness of it isn’t an issue and you can leave it in a protective cover.

The bike does not have a charging point for your devices or speakers.

The exercise bike is manual and doesn’t require to be plugged into a socket nor does it need batteries.


  • Magnetic resistance
  • Belt drive
  • Low maintenance and quiet
  • Comes with a tablet holder
  • Bike fittings allow the seat and pedals to be easily changed out
  • Sensors can be fitted to use with fitness apps for cadence
  • 4 way adjustable seat and handlebars make it easy to get best fit for people with inseam between 28 ins and 38 ins
  • Suitable for people up to 300 lbs
  • Assembly is straightforward
  • Provides a solid platform for workouts
  • Has transport wheels to move bike
  • Bike doesn’t require power to use


  • No guard for the resistance and flywheel
  • Doesn’t come with SPD pedals
  • Doesn’t have a console
  • Resistance isn’t measured
  • Requires some assembly on arrival
  • Nowhere to hold dumbbells

Consumer Ratings

Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike ReviewConsumer reviews on the whole are positive. They like the build of the bike, how smooth it is and quiet. They get a good workout.

Many have chosen to use it successfully with the Peloton Digital App and added items to enhance the experience. It can be used with any indoor cycling workout class or without.

There are some that have had problems with the bike due to manufacturing issues but mainly with damage suffered when being shipped. For some this has been compounded with poor customer service.

However, for those that have had a bad experience they are at least matched by those that have had a very good customer service experience with the company responding quickly and positively to their problem.


You are paying for the magnetic resistance, belt drive, 44 lbs flywheel and solid build which makes it cost more than other indoor bikes from Sunny.

However, it is less than the price of the Peloton.

You don’t get many extras with the bike. But these can be added as you want including sensors, pedals and seat replacement. It still will be an economical buy.

When I checked at Amazon it qualified for Prime and free delivery on eligible orders.

Check for latest pricing and availibility here
Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike

Review Summary

It seems it is reliable and durable bike. The belt drive and magnetic resistance make it a low maintenance and quiet bike suitable for the home.

It can be used by beginners and more experienced users to get a low impact cardio workout to help meet their differing fitness goals from getting fit, weight loss, improving fitness and beyond. You can have moderate low intense exercise through to high intense interval training.

It is a popular bike with those who want a good basic bike to use with the Peloton Digital App. It can be used with other Fitness Apps and videos too. With the addition of sensors and SPD pedals it can provide an improved experience. But most of benefits of the workout can be had with just the bike.

Whether it’s used with Peloton or App it does provide a good solid basis for those who want to work on their fitness at home.

2 comments for “Sunny Health & Fitness SF-B1805 Magnetic Belt Drive Indoor Cycling Bike Review

  1. Paul Norton
    May 19, 2020 at 11:59 pm

    I just bought it, and I found there is not enough resistance. If you are a stronger cyclist, then, you should look for a different bike.

    • Paul
      May 20, 2020 at 7:13 pm

      Sorry to hear about your issue with resistance. Thanks for leaving the feedback. Out of interest did you contact Sunny to see if they had any suggestions on it?

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