Sunny SF-B1002 Belt Drive Indoor Cycling Bike Review

The Sunny SF-B1002 Belt Drive Indoor Cycling Bike is the top spin bike in the popular SF range from Sunny Health and Fitness, with a 49 lb flywheel and friction pad resistance system.

In this review we take a look at whether the design features meet our expectations for a bike at this price range, as well as the assembly required, customer reviews, and how it compares to other spin bikes in the Sunny collection.

Frame design and adjustment options

If you’re already familiar with the design of spin bikes, you might be used to hearing about a bike’s ‘Q Factor’.

Sunny SF-B1002 Belt Drive Indoor Cycling Bike

This is defined as the distance between the pedal attachment points on the crank arms when measured parallel to the bottom bracket axle.

Various studies have shown that generally speaking, the shorter the Q Factor, the more efficient your cycling experience will be.

This is due to a more effective transfer of power from your legs to the pedals, at a distance that requires virtually no sideways movement of your knees, also helping reduce the risk of injury.

Measuring the Sunny SF-B1002 against the other spin style bikes in the range, this design is amongst the top 2, with a Q Factor of 7.5 inches (the best being SF-B901 with a measurement of 7.13 inches).

In terms of the adjustment options, both the seat and handlebars provide a variety of possible height positions.

Unfortunately only the seat can be adjusted horizontally, although full handlebar adjustment is available on the SF-B1110 if this is a feature important to your workouts.

One final area of adjustment can be found in the form of base levelers, with 4 evenly spread around the base of the frame.

These can be rotated if needed to help counteract any unevenness in the floor the bike is resting on, increasing the bike’s stability.

The overall footprint of the frame is also incredibly compact, which is ideal for anyone that’s looking for an effective cardio workout, but doesn’t have the space for larger equipment.

Sunny SF-B1002 Belt Drive Indoor Cycling Bike

Sunny SF-B1002 – Features Summary

  • Fully adjustable seat and handlebar
  • Heavy duty steel frame with a 49lbs flywheel
  • Belt drive mechanism for smooth and quiet workouts
  • Adjustable resistance with a press down brake system
  • Transportation wheels for easy portability

Belt driven flywheel

Although the SF-B1002 is also available with a chain driven flywheel system, this particular review is based on the model which is belt driven.

This is because it’s such an uncommon feature to find on mid-range spin bikes, with the majority of the bikes in the Sunny range only offering a chain driven system.

The most noticeable benefit is the fact that your workouts are a lot quieter, but some users have also reported a smoother motion when cycling and switching between resistance levels.

The flywheel itself weighs an impressive 49 lb, which is heavier than many of its higher priced competitors.

Having a heavier flywheel provides a smoother cycling motion, which closely emulates the feel of riding an outdoor road bike.

Friction pad resistance system

A friction pad resistance system has been used instead of eddy current magnetic resistance

Unlike most upright bikes, spin style bikes tend to rely on one of two resistance systems; magnetic and friction pad.

Spinning bikes that rely on a friction pad system will usually require a little more maintenance, due to the inevitable wear and replacement of the friction pad.

Also, setting the resistance is performed manually, rather than by pressing a button on the display console or adjusting a lever. This can make it slightly more difficult to keep track of the current resistance level.

But apart from the small amount of additional maintenance and minor difficulty in tracking changes in resistance level, there’s no real negative impact on the quality of your cycle.

The Sunny SF-B1002 relies on a friction pad resistance system, with a single pad applying pressure to the flywheel based on the rotation of the resistance knob directly in front of the seat.

An emergency brake option is also available for stopping the rotation of the flywheel immediately, and can be activated by pushing down rather than rotating.

Ergonomic handlebars and seat

Multiple grip positions are available thanks to the ergonomically designed handlebars

If you’ve used a spinning bike before, either at home or part of a group cycle class at your local gym, you’ll know how important it is to be able to switch between different grip positions.

Whereas your posture on an upright or recumbent bike probably won’t change a great deal throughout your workout, due to the higher level of training intensity, this isn’t the case with spin bikes.

During periods of lower intensity cycling you need the option to sit back on the seat and maintain a grip that’s closer to your body. As soon as you switch to a sprint or time trial, you’re going to want to shift your bodyweight forwards, requiring a different grip to support more bodyweight.

This is why the Sunny SF-B1002 features a set of ergonomically designed handlebars, with the wide range of angles providing support for all of the most common grip positions.

The seat is also much narrower than upright bikes, which some people can find uncomfortable during the first couple of weeks if they’re not used to this style of cycling.

Fortunately, the saddle can be covered with a softer gel saddle cover if required, with the Cloud-9 from Sunlite being the most popular choice.

Ease of assembly

Attention to detail in the packaging and user manual ensure the bike is well protected during transit, and easy to assemble when it arrives

Before we go into a bit more detail about the assembly instructions, we first wanted to mention just how well this bike is packaged before being shipped.

This is something we’ve noticed throughout the reviews of all Sunny spinning bikes, in that there are hardly any negative customer reviews that complain about damage in transit.

Specifically looking at the Sunny SF-B1002, the majority of the assembly has already been completed for you before you even open the box. Even the flywheel and height / resistance adjustment knobs are attached.

But to cut down on the size and awkwardness of the box during shipping, the base stabilizer bars are kept separate.

Without the stabilizers in place, the weight of the bike would normally be left resting on the thinner strips of metal that are designed to attach the stabilizers to the main frame, leaving them open to damage if the box was dropped or put down heavily.

To make sure this doesn’t happen, Sunny attach a dummy base stabilizer at the front and back, which is essentially a short strip of metal tubing matching the width of the frame.

These can easily be removed and discarded once the bike is delivered, but do an excellent job of providing an extra layer of protection as it travels between the distributor and your door.

In terms of the assembly itself, there are actually surprisingly few moving parts to worry about.

All that’s left to attach are the base stabilizers, pedals, water bottle holder, seat, and handlebars.

Even the process for attaching each of these has been kept as simple as possible, with all that’s required in most cases being to join the parts together with a pair of bolts and washers.

Due to the clarity of the assembly instructions and recently updated user manual, the entire process is well explained, with exploded drawings and a full parts list making the whole process even easier.

Our total recommended assembly time is just 30 minutes once you have all the parts unpacked. Having someone available to assist you in attaching the base stabilizers can be useful – due to the 49 lb flywheel weight – but isn’t compulsory.

Bikes available from Sunny Health and Fitness

Although the Sunny SF-B1002 is generally considered the flagship spinning bike in the range (together with its chain driven counterpart – the SF-B1002C), there are a number of other bikes that may actually be a better fit for your goals or budget.

We’ve reviewed each of these models on this site, and can say that they all vary in terms of the combination of drive system, flywheel weight, adjustment options, price, and weight limit that they can provide.

This includes the SF-B901, SF-B1001, SF-B1110, and SF-B1203.

The following list contains a few key differences between these bikes, and is ordered in terms of price (highest to lowest):

  • SF-B1203 – 22 lb flywheel, 240 lb weight limit, chain drive
  • SF-B1001 – 30 lb flywheel, 220 lb weight limit, chain drive
  • SF-B901 – 40 lb flywheel, 275 lb weight limit, chain drive
  • SF-B1110 – 44 lb flywheel, 265 lb weight limit, chain drive
  • SF-B1002 – 49 lb flywheel, 275 lb weight limit, belt drive

Customer reviews

With spinning bikes usually costing anything from $100 up to $2500, you might be forgiven for thinking that a bike that was available for less than $400 wouldn’t be particularly high quality.

But you only have to take a look at the distribution of rating scores for the Sunny SF-B1002 to see that this isn’t the case.

It seems to be a trend with the spinning bikes from Sunny Health and Fitness that they maintain an impressively high average rating, no matter how many reviews they have.

In this case 90% of reviewers have awarded a rating of either 4 or 5 stars.

After reading through each of these reviews ourselves, the reasons behind the high ratings became much clearer, and matched with what we’ve seen in our own review.

It’s important to take into account both the good and the bad points, which is why we’ve provided the following lists of pros and cons as a quick reference summary of the reviews available on Amazon.


  • Interchangeable seat
  • Belt drive provides a much quieter workout than its chain driven version
  • One of the heaviest flywheel weights available for a non-commercial spinning bike
  • Smooth, stable cycling motion
  • Incredibly easy to put together
  • High build quality makes this a bike that can be considered an investment, rather than something that you will need to upgrade in a couple of years
  • Easy to move around if required
  • Good number of adjustment points
  • Well packaged
  • Excellent level of response from customer service


  • Lack of resistance level indicator makes it difficult to keep track of a specific resistance between workouts, and after multiple rotations
  • No display console provided means that you can’t track basic workout information

What’s covered by the warranty?

  • Frame: 1 year
  • Parts: 90 days

About the company

Despite being a fairly new fitness equipment company in relation to the likes of Schwinn and ProForm, Sunny Health and Fitness has quickly established itself as one of the leading designers of affordable exercise bikes for lower budgets.

One of the reasons for their popularity is undoubtedly their focus on affordability, but this certainly isn’t the only reason why their bikes are backed by such high review ratings.

The difference is that they manage to provide the highest level of build quality and many high-end features, despite the lower price point.

Sunny Health and Fitness Exercise Bike Guide

Review Overview

Overall Review Rating

4.5 / 5

Aside from being their highest spec spin bike, the Sunny SF-B1002 is also one of the company's highest rated across various online review sites.

This is based on the high build quality, excellent stability, and smooth cycling motion that come as a result of including many of the features you would expect to see on bikes twice the price, including the 49 lb flywheel.

Although we would have liked to see a longer warranty on the frame and parts, and perhaps some form of workout tracking, these are really both things that are rare to find on any spin bike under $400.

Overall, if you're looking for a compact exercise bike with enough resistance and frame strength to support years of high intensity cycling workouts, you won't be disappointed with the SF-B1002.

Product dimensions: 50" (H) x 20" (W) x 44" (L) Product weight: 115 lbs Weight limit: 275 lbs