Guardian Bikes: 5 Reasons We Love Them

What is Guardian Bikes?

Guardian Bikes is a kids’ bike company based out of California that was thrust into the spotlight in 2017 after they landed a deal with Mark Cuban on Shark Tank.  Guardian’s main differentiator from other online child “boutique” bike brands is their innovative SureStop braking system.

Designed and patented by the founders of Guardian Bikes, the SureStop system is the first major innovative change to standard bike braking systems in decades.   The SureStop system allows riders to stop faster and with more control as compared to traditional braking systems (both hand and foot brakes) found on kids’ bikes.

We’ve personally tested every model in Guardian’s line-up with lots of different kids to determine just how well they stack up to other kid-specific bike brands on the market.  From their 16″ bike for beginning riders to their 24″ bike for experienced 8 to 11-year-olds, our testers and parents all love the overall build and quality Guardian bikes offer, as well as their innovative braking system.

Why Buy a Guardian Bike?

  1. Fun and Safe Braking – No chance of going over the handlebars!
  2. Simplified Braking – One brake lever controls both the front and rear brakes
  3. Two Pricing Levels – Different pricing levels to accommodate different budgets
  4. Quality Build with Fun and Colorful Designs – Great quality parents want, fun graphics kids love
  5. Four Size Options – Various sizes to accurately fit kids ages 4 to 12

1. Fun and Safe Braking

Guardian’s proprietary braking system allows kids to brake faster and with more control than traditional braking systems.  The SureStop system also completely eliminates the risk of a child being thrown over the handlebars as a result of braking with the front wheel instead of the rear.

In addition to adding an extra level of safety, Guardian’s braking system makes braking more fun!  Over the years we have had many kid testers describe how braking is not only “fun” on a Guardian, but that they also felt more in control while braking.  As a result, many previously timid riders have gained confidence while riding a Guardian. With less anxiety about stopping the bike, they were willing to ride more adventurously.

Girl riding 20" Guardian kid's bike down the sidewalk. (Turquoise)

Never wanting to miss out on the fun, we parents have hopped on our kids’ Guardians and tried out the brakes for ourselves. We quickly understood our testers’ perspectives.  Like feeling anti-lock brakes in your car go into action, SureStop brakes not only feel different than standard brakes, you feel much more in control of the bike as you stop.

How Does the SureStop System Work?

Guardian’s unique braking system allows the rear and then the front brake to be activated sequentially with the pull of ONE brake lever.   The SureStop system uses standard brake calipers, so upon first glance, their braking system looks very similar to most dual hand brake bikes.  The difference, however, is in the rear brake’s ability to activate the front brake.

Graphic showing three steps to Guardian's SureStop braking system. Step One: Child activates brake lever, Step Two: Rear Brake Engages, Step Three: Rear brake activates front brake.

The secret lies in Guardian’s proprietary rear brake pad that responds to the friction created between the brake pad and the wheel’s rim when the rear brake engages.  This friction between the rim and the brake pad pushes the pad slightly forward.  When the pad slides forward, it pulls on the attached wire that then triggers the front brake to engage.

On Guardian kids' bikes, the rear brake pad slides slightly forward due to friction from the rim, and then the wire on brake is pulled which triggers the front brake.

Is the SureStop System for Everyone?

Almost everyone! The SureStop system is amazing for everyday kid riders but is not recommended for technical riding.  If your child is planning on mainly hitting the mountain bike trails, the Guardian system isn’t ideal because technical trail riders need to brake the front and rear wheels independently.  The SureStop system is designed for the average child rider who mainly rides on paved surfaces or dirt paths.

Is the SureStop System Safe?

Yes!  The SureStop system uses high-quality brake calipers like those found on many other higher-end bikes.  The only difference between the SureStop system and a regular dual hand brake system is that the brake pad on the rear brake engages the front brake.  If for some reason the SureStop system were to fail (which we have never seen in our years of testing), the rear brake on the bike would still work, just not the front brake.

5-year-old Boy and Girl on 16" Guardian kids' bikes - pink and blue


2. Simplified Braking

Dual hand brakes work great for advanced riders and are essential for technical youth riders (such as mountain bikers), but can be confusing for the average child rider.  If they accidentally brake with just the front brake, the front tire can lock up, which causes the rear tire to come off the ground and potentially throw the child off the bike. 

Sadly, we have seen this happen several times.  With ONE brake lever on the Guardian, a child cannot accidentally brake incorrectly.  They simply squeeze one brake lever and the SureStop system takes care of the rest.

Single brake lever on Guardian 20" kid's bike


3. Two Pricing Levels

To accommodate various budgets, Guardian offers all of its models in two different lines – their entry-level “Ethos” line and their premium “Original” line.  Both lines come standard with the same SureStop braking system.

The Ethos line, however, has a steel frame versus aluminum, a threaded headset versus a threadless, and has a slightly lower level of components in the drivetrain.  Although the Ethos and Original lines feature different frames, the geometry (the body position of the child on the bike) is the same on both lines.

Guardian Original vs. Guardian Ethos


4. Quality Build with Fun and Colorful Designs

Guardian bikes are built with lightweight aluminum frames and many of the same high-end components of other child-specific brands.  We’ve found their build quality to be on par with, and often better than, most kids’ bikes manufactured by the major bike brands. 

Compared to other online child-specific brands, Guardian’s quality is also on par with other bikes in its price range.  With several amazing child-specific brands on the market, Guardian does have some tough competition. But for everyday neighborhood riders, especially those who would benefit from extra stopping power, the Guardian is our bike of choice.

To ensure quality and ease of assembly, every Guardian bike is checked, tuned, and re-packaged by Guardian’s own mechanics in California BEFORE they are shipped out to customers.  Bikes are NEVER shipped straight from the factory to the consumer. Guardian bikes are ridiculously easy to assemble and can typically be put together in less than 15 minutes.

The color-schemes and designs of Guardian’s bikes are also very unique and very kid-approved.  From the contrasting rims to their fun geometric designs, kids are drawn to the look of Guardian bikes.


5. Four Size Options

Guardian Bikes are available in 4 different sizes ranging from 16″ to 24″ wheels.  Their 16″ and 24″ bikes come in one size each, while their 20″ comes in two sizes. Like the 16″, the 20″ small is a single-speed designed for beginning to everyday riders.  The 20″ large size, like their 24″ size, has gears for more advanced riders.

Guardian Bikes Sizes

Features16"20" Small20" Large 24"
Guardian Ethos 16" kid's bike in black and blueguardian ethos 20" kids' pedal bike red white blackGuardian 20" geared kid's bike in black, blue, and greenguardian 24" kids' bike - red grey white black
Size16"20" Small20" Large24"
Est. Age4+5+6+8+
Ethos Model$259$279$319$339
Original Model$359$379$419$439
Child's Height Range40" - 46"43" - 51"45" - 53"49" - 61"
Seat Height18.5" - 23.5"20.8" - 26.8"22.5" - 28.5"25" - 33"

Guardian’s Virtual Bike Sizer

To help make purchasing the right size bike for your child easy, Guardian created a unique and clever tool called RideSizer.  Simply enter your child’s height and birthday, and RideSizer will display an avatar of your child’s size on whichever size bike Guardian recommends for your child.  You can also change the bike to other sizes to see how your child would fit on them.

As an added bonus, if you enter your email into the RideSizer, Guardian will email you a chart of their estimations for how long your child will fit on the bike.

Based on our experience, the RideSizer tool works great, but if your child is right on the edge between two sizes, be sure to compare their inseam to the bike seat height to ensure a perfect fit.


Detailed Guardian Bike Reviews by Size

Guardian 16-inch

Guardian 16″ Bike Review

Built on a lightweight frame with a low center-of-gravity design and complemented with upright handlebars, the Guardian 16″ is easy to balance and easy to maneuver.

The Guardian 16″ bikes have a semi-upright body position and no-coaster brake, which makes them a great choice for both first-time pedal bike riders as well as experienced riders looking for a great quality bike for riding around the neighborhood.

Guardian recommends their 16″ bikes for kids ranging from 40″ to 46″ in height.  We tested the bike with kids ranging from 42″ to 47″ tall and found the bike to be the best fit for kids 42″ to 45″ tall.

Experienced pedal bike riders only 40″ to 41″ tall will also fit on the bike, but they will need to rely solely on the brake lever to stop the bike as they won’t be able to reach the ground with their full foot.  Both the Original and Ethos Guardian 16″ bikes are not compatible with training wheels, so kids under 40″ tall will not fit on the bike.

Guardian’s SureStop braking system is what really makes these bikes shine.  The SureStop system stops the bike using the power of two v-pull caliper brakes, like many high-end kids’ bikes. However, it simplifies the process for kids by allowing them to pull just ONE brake lever to activate both brakes.

4 year old boy riding the Guardian 16" Ethos bike down the sidewalk

No Coaster Brake!

While many parents think coaster brakes are just a normal part of 16″ kids’ bikes, we absolutely love that Guardian’s 16″ bikes do not have a coaster brake (back-pedal brake).  Coaster brakes can be very confusing for kids new to pedal bikes.

When learning to balance a bike, both kids and adults naturally pedal backward when they lose their balance.  Upon doing so on a bike with a coaster brake, the brake is unexpectedly activated, which often causes kids to fall. This process can be very frustrating for young riders which can then delay their mastery of a pedal bike.

On a bike without a coaster brake, a child can naturally pedal backward without activating the brake. Once they regain their balance, they can continue to pedal forward without a break in the momentum they just gained on the bike.

With SureStop, the difficulties that can arise with coaster brakes, as well as dual-hand brakes, are both eliminated.

Guardian’s Original vs. Ethos Line

Guardian’s 16″ bikes from the two lines are the same size, come in almost identical designs, and both feature Guardian’s unique braking system (SureStop). Where they differ is in components.

In the image below, the simplified graphic design can be seen on the Ethos line on the right as compared to the Original line shown on the left.  The steel tubing on the Ethos is also thinner than the aluminum tubing on the Original.  Both bikes, however, feature a pop of color in the rims.

Guardian 16″ Original and Ethos BikesSide by side comparison of 4 year old boy riding the Guardian 16" Ethos bike and Guardian 16" Original bike down the sidewalk

The lighter Guardian Original is ideal for lightweight and timid kids (as well as those who simply want the best), while the Guardian Ethos is a great choice for those riders who can handle a slightly heavier bike as well as those on a tighter budget.

Compared to similarly priced 16″ bikes, however, the Ethos is still pretty light as it is almost a pound lighter than the Raleigh MXR 16 and 1.5 lb. lighter than the Specialized Riprock.

Features16" Original16" Ethos
Guardian 16" Original kid's bike in black and blueGuardian Ethos 16" kid's bike in black and blue
16" Original16" Ethos
Seat Height18" - 23.5"18" - 23.5"
Weight16 lb.17.5 lb.
BrakesSureStop, no coasterSureStop, no coaster
DecalsUpgraded Heat Bonded GraphicsTraditional Water Transfer Graphics

Seat Height

The seat height on both 16″ Guardians ranges from 18.5″ to 23.5″.  If the Guardian is a child’s first experience riding a pedal bike (without training wheels) they will need an inseam of at least 18.5″ to fit on the bike (usually kids’ in 4T pants).

First-time bike riders need to be able to place their entire foot on the ground while standing over the seat in order to comfortably start and stop the bike while they are learning to balance and use a handbrake.

For those kids who are already comfortable riding a pedal bike without training wheels, if they have an inseam of at least 16.5″, they can fit on a 16″ Guardian.  Experienced riders only need to be able to touch the ground with their tip-toes as they are comfortable starting and stopping a bike without using both of their feet.

When choosing the right size Guardian bike, be aware the Guardian’s 20″ Small bike size can have some overlap with the 16″. Both our 42″ tall tester in the red shirt and our 47″ tall tester in the striped shirt below, loved the 16″ Guardian, but the 47″ child was a much better fit on Guardian’s 20″ Small.

Guardian 20″ Small Ethos and 16″ Ethos

4 and 6 year old boys sitting side by side on their Guardian bikes. 20" small in red and 16" in blue.


Handlebars & Body Position

Guardian 16″ bikes are designed for beginning riders who often prefer an upright body position.  Sitting upright centers a child’s weight over their hips, just like they’re accustomed to when standing and walking. As a result, beginning riders are usually able to master balancing a bike faster when sitting upright.

Experienced riders, however, may prefer a bike with lower handlebars that place the rider in a more aggressive position.  A more aggressive position better allows the rider to shift their body weight during turns and while on hills.

Compared to other higher-end bikes, the Guardian 16″ is not as upright as the woom 3, but much more upright than the Cycle Kids 16″.

Body Position on Guardian 16″ Original

Side by side comparison of three 16" bike, showing body position of rider. woom 3 is most upright and cyclekids is most aggressive. Guardian 16" is in the middle.


The aluminum-framed 16″ Original weighs 16 lb. while the steel-framed Ethos weighs 17.5 lb.  Compared to similarly priced bikes, the Guardian models are slightly heavier, but not by much.

Much of their difference in weight is due to the rims and tires on the Guardian bikes.  To keep the tires properly aligned through kids’ many adventures, Guardian’s bikes come with a beefier rim than most 16″ bikes and have a lot more spokes as a result.  The additional spokes help keep the tire properly true, even when repeatedly going down jumps or curbs.

The 1.75″ wide tires on the Original line are also wider, and therefore heavier, than most bikes.  The Ethos’ tires, however, are the standard 1.5″ width found on most 16″ bikes.

In addition to providing slightly more cushioning and traction, Guardian has found that kids prefer the look of the wider tires.  Based on our experience, however, for the average everyday rider (not all-terrain riders), the width of a child’s tires makes very little difference in the bike’s performance.

Gain Ratio

The gain ratio on a single-speed bike is a number that represents that single gear, or how hard or easy it is to get started pedaling and maintain fast speeds.

The gain ratio on both 16″ Guardian bikes is mid-range at 3.55.  This makes the bike geared perfectly for cruising around the neighborhood.  As a comparison, the Cleary Hedgehog is designed for aggressive riding around hills and is geared at a low 2.88 while the Cycle Kids 16″ is geared high at 4.3 for faster riding on flat surfaces.

Bottom Line

Guardian’s combination of SureStop brakes, lightweight frames, and upright positioning make their 16″ line of bikes one of our top choices for 4 to 6-year-olds riding around the neighborhood and paved bike trails.  The Original line is an exceptional bike offering upgraded graphics, sleek aluminum tubing, and a lightweight build, while the Ethos line provides top-notch performance for its price.

Both bike lines are a best fit for kids with at least an 18″ inseam (for those riding a pedal bike for the first time).

Guardian 20-inch Small (Single-speed)

Guardian Bikes 20″ Small –  Single Speed Review

To meet the needs and size range of kids ages 5 to 8, Guardian offers 2 different sizes of 20″ bikes – a 20″ large and 20″ small. While the wheels size remains consistent, the frame size and gearing options differ.

To fit the needs of younger riders, the 20″ small Guardian Bikes have a smaller frame and lower minimum seat height than the 20″ large bikes.  The 20″ small bikes are also single-speed (no gears) while the 20″ large models comes standard with 6-gears.

Both the 20″ large and small sizes are available in their entry-level Ethos line as well as their premium Original line.

20″ Small Models

Built for the beginning rider who a little too tall for a 16″, the Guardian 20″ small size offer plenty of room for growth, without the added complexity of gears. The single-speed 20″ small size is smaller than most 20″ bikes yet still has the added benefit of a smoother ride than can come with larger tires.

7-year-old riding Guardian Ethos 20" Small bike in black and red

Guardian 20″ Small

The Benefits of a Single-speed Bike

Although most high-end 20″ kids bikes come with gears, the 20″ small is only available as a single-speed.  Over many years, we’ve found that unless a child really needs gears to travel long distances or over hills, single-speed bikes are better for kids ages 5 to 8.  In addition to being more complicated to use, geared bikes require somewhat regular maintenance, which can quickly add up in cost.

The main issue with smaller geared bikes is that the derailleur (the component that changes the gears on the rear wheel) on essentially ALL 20″ geared bikes sits very low to the ground (this includes high-end brands as well).  As a result, they can get beat up pretty regularly and then can stop working.  For those who NEED gears, however, they make a huge difference between a child’s ability to ride for longer distances or on varied terrains.

The back wheel of a 20" single speed Guardian bike with no derailleur, and the back wheel of a 20" geared Guardian bike with a derailleur.

Ethos vs. Original

The main benefit of the Original over the Ethos on the 20″ small line is the pound of weight you save with the Original.  The aluminum frame and upgraded components are lighter and are certainly a benefit to lighter-weight or more timid riders.

Guardian 20" Small Models

Features20" Small Ethos20" Small Original
guardian ethos 20" kids' pedal bike red white blackguardian original 20" kids' bike - red white black
MSRP$279 $379
Seat Height20.8" - 26.8"20.8" - 26.8"
Weight20.7 lb.19.6 lb.
DecalsTraditional Water Transfer GraphicsUpgraded Heat Bonded Graphics

Guardian 20-inch Large and 24-inch Geared

Guardian Bikes 20″ Large and 24″ – Geared Review

Built for slightly older or taller kids, the 20″ large and 24″ models are geared to help kids take their riding to the next level.  The 20″ Large has 6 gears while the 24″ has 7 gears.  The 20″ Large is comparable in size to most 20″ kids bikes on the market while the 24″ is on par in size with most 24″ bikes.

Ethos vs. Orginal

In addition to the upgraded aluminum frame on the Original line, the shifters and derailleurs on Guardian’s geared bikes are also upgraded on the Original.  While not hard to use, the shifter on the 20″ Large and 24″ Ethos takes more effort to engage than the shifter on the Original models.  The upgraded shifter of the Original is also narrower, making it easier for kids to wrap their hand around the grip shifter.

Side by side comparison of the grip shifter on the Original Guardian vs the Ethos line. The shifter on the Original has a smaller diameter and so a child's grip over it is smaller and more natural.

Being wider, the extra “bump” on the Ethos shifter can require kids with a hand length of 5″ or less to slightly loosen their grip in order to activate the brake lever.   The only time we saw this concern was a smaller rider who barely fit on the 20″ Large geared.

All in all, for the average rider who shifts more for fun than necessity, the Ethos shifter will likely work just fine, but for those who need to shift out of necessity, the upgraded Original is worth the additional expense.

Guardian 20" Ethos vs. Original

Features20" Large Ethos20" Large Original
guardian ethos 20" large geared kids' bike - blue greenGuardian 20" geared kid's bike in black, blue, and green
Bike20" Large Ethos20" Large Original
Seat Height22.5" - 28.5"22.5" - 28.5"
Weight22.9 lb.21.2 lb.
Shifters6-speed/Standard Shimano grip shift6-speed/Upgraded Shimano grip shift
DecalsTraditional Water Transfer GraphicsUpgraded Heat Bonded Graphics

Guardian 24" Ethos vs. Original

Features24" Ethos24" Original
Bike24" Ethos24" Original
Seat Height25" - 33"25" - 33"
Weight25.5 lb.23 lb.
Shifters7-speed/Grip shift7-speed/Shimano grip shift
DecalsTraditional Water Transfer GraphicsUpgraded Heat Bonded Graphics

Guardian Bikes Bottom Line

Safe, lightweight, and fun to ride, Guardian’s line of bikes is simply amazing. Whether cruising the neighborhood or enjoying extended family bike rides, your child will be in good hands with a Guardian.

For a great quality mid-priced bike, the Ethos line provides a fantastic bang-for-your-buck, while the Original line provides top-notch components, including upgraded shifters paired with a lightweight aluminum frame.


FTC Disclosure: Affiliate links are included in this review.  No monetary compensation was provided for this review, however, the reviewed product was supplied by the manufacturer or distributor to help facilitate this review. All opinions and images are that of Two Wheeling Tots LLC.  All content and images are copyrighted and should not be used or replicated in any way. View our Terms of Use.


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