Shopping for a 20 Mountain Bike for your child can feel overwhelming. Whether you’re looking for a versatile bike for neighborhood rides and light trails or a robust machine ready for more challenging terrains, the options are plentiful. Investing in quality gear significantly impacts performance in mountain biking, but how much bike does your young rider truly need?
The qualities that make a 20 inch mountain bike exceptional differ greatly from adult bikes, or even larger kids’ mountain bikes. Features like overly slack geometries, suspension forks, dropper posts, and large cassettes, while beneficial on adult bikes, can actually hinder young, lightweight riders on 20 inch bikes by adding unnecessary weight and complexity.
So, what defines an outstanding 20” MTB? It boils down to matching the bike to your child’s skill level, riding style, and your budget. Having rigorously tested over 50 different 20 inch bikes, this guide will outline the crucial factors to consider when choosing a 20 inch mountain bike (click to jump to that section) and present our top picks across various price points.
A young girl confidently navigates a downhill trail on her woom OFF 4, a top-rated 20 inch mountain bike, showcasing its capability and lightweight design ideal for young riders.
Best 20 Inch Mountain Bikes
| Bike | Why It Stands Out | MSRP |
|---|---|---|
| Beginning 20 Inch Mountain Bikes – Quality geared bikes with knobby tires for basic trails | ||
| Polygon Ultralight | Lightest bike under $300 by 4 lbs! | $289 |
| Prevelo Alpha Three | Exceptionally nimble, wide gear range | $599 |
| Rigid Trail Bikes for Progressing Riders – Trigger shifters, disc brakes, 7+ gears, rigid fork | ||
| Commencal Ramones 20 | Great components, geometry for the price | $540 |
| Pello Rover | Versatile for on and off the trail | $589 |
| woom OFF 4 | Lightest legit MTB on the market! | $849 |
| Front Suspension Bikes for Progressing Riders – Trigger shifters, disc brakes, 8+ gears, air fork | ||
| woom OFF AIR 4 | Super light weight MTB with air fork | $1099 |
| Prevelo Zulu Three | Aggressive trail geo, 9 gears, 80 mm fork | $1199 |
| Trailcraft Blue Sky 20 | Most lightweight, customizable high-end builds | $1899 |
| Bikes We DON’T RECOMMEND for True Mountain Biking | ||
| REI REV 20 Plus | Heavy with basic components | $399 |
| Specialized Riprock 20 | Geometry too aggressive for most riders | $600 |
PROPER BIKE SIZING: Remember, while all these bikes feature 20″ wheels, their overall size varies considerably. Always check the bike’s minimum seat height (provided in the descriptions below). For an ideal fit, your child’s inseam should be 2″ to 3″ shorter than the bike’s minimum seat height. Refer to our kids bike sizes guide for detailed fitting advice.
BASIC 20 INCH MOUNTAIN BIKES – Entry-Level Trail Riders
While high-end features like suspension forks, trigger shifters, and hydraulic disc brakes are indispensable for adult mountain bikes, they aren’t always necessary for young beginners exploring basic trails.
For young, entry-level riders, especially those on 20 inch mountain bikes, their lighter weight means they often don’t benefit from standard suspension forks. Affordable suspension forks are often too stiff for lighter riders to effectively compress and utilize. Furthermore, beginners generally ride at slower speeds than adults, lessening the immediate need for the enhanced stopping power of hydraulic disc brakes.
So, for children starting out on basic trails, what are the essential features to look for without overspending?
- Durable, lightweight frame: Crucial for easy handling and maneuverability.
- Reliable, dual handbrakes: Ensuring safe and effective stopping power.
- User-friendly gears: Simple shifting to help kids learn and manage varied terrain.
- Knobby tires: Providing essential traction on dirt trails.
How much should you budget for a 20 mountain bike? Invest as much as comfortably fits your budget, but avoid “overbuying” for a beginner. If your child is new to mountain biking and will primarily ride basic trails, any bike in this beginner category should be perfectly adequate.
While higher-priced bikes offer superior components and a better overall riding experience, you don’t need to spend a fortune to start enjoying trail riding. These beginner 20 inch mountain bikes offer a fantastic entry point to the sport.
Best Value Under $350
A 6-year-old confidently rides the Polygon Premiere 20 inch kids bike, highlighting its lightweight design and suitability for young riders venturing onto single-track trails for the first time.
Polygon Premier Ultralight
$319 – $349
BEST FOR: Families seeking the best 20 mountain bike for beginners venturing onto single-track or mountain biking on a budget.
View on Ultralight Urban
View on Ultralight MTB
Our Review
About the Polygon Premier Ultralight Models
The Polygon Premier Ultralight series includes two models: the Urban and the MTB. Both share the same lightweight frame and drivetrain. The Urban model features a rigid fork paired with all-terrain tires, while the MTB version is equipped with a suspension fork and wider, off-road tires, making it a true 20 inch mountain bike.
Polygon’s Premier Ultralight bikes strike an ideal balance – not overly basic, yet not overly technical. They offer the lightweight agility young riders need, combined with enough technical capability to confidently handle trails, even the Urban version! These bikes are excellent 20 mountain bike choices for beginners.
| Ultralight Urban | **Ultralight MTB** |
|---|---|
| MSRP | $299 |
| Weight | 21.1 lb. |
| Seat Height | 21.25″ – 27.25″ |
| Tire Width | 1.75″ |
| Max Tire Width | 2.1″ |
| Gearing | 7 speed, grip |
| Cassette | 14-28T |
| Brakes | V-pull |
| Fork | Rigid |
| Head Tube | 69° |
| Seat Tube | 72° |
While the Urban model is designed as a versatile bike for both pavement and light dirt trails, its lightweight construction and reliable brakes make it surprisingly capable on basic singletrack. For those planning frequent trail rides, we recommend swapping the Urban’s 1.75″ all-terrain tires for wider 2.0″ off-road, knobby tires to enhance its performance as a 20 inch mountain bike.
For children eager to tackle trails from the outset, the Mountain Bike (MTB) model comes equipped with 2.0″ knobby tires and a 40mm Suntour coil fork. While these upgrades enhance the MTB’s off-road capability, they do add approximately a pound to the bike’s overall weight.
For more aggressive riders or children with larger builds, the extra pound might be a worthwhile trade-off for the added capability. However, for timid or petite riders, we suggest opting for the rigid Urban model and upgrading the tires to optimize weight and performance for a true 20 mountain bike experience.
Lightweight and Nimble
A young girl skillfully maneuvers her Prevelo Alpha Three 20 inch mountain bike through a rooty section of trail, showcasing the bike’s nimble handling and lightweight design ideal for young trail enthusiasts.
Prevelo Alpha Three
$599
BEST FOR: Beginner to intermediate mountain bikers needing a lightweight and nimble 20 mountain bike. For riding on more challenging, chunkier terrain, consider upgrading to Prevelo’s wide trail tires.
About the Prevelo Alpha
Although the Prevelo Alpha Three is marketed as an all-purpose bike, it truly shines as an excellent beginner 20 inch mountain bike for young riders venturing onto basic trails. Its exceptionally lightweight and nimble nature quickly fosters confidence in budding trail riders.
| Prevelo Alpha Three |
|---|
| MSRP |
| Weight |
| Seat Height |
| Tire Width |
| Max Tire Width |
| Gearing |
| Cassette |
| Brakes |
| Fork |
| Head Tube |
| Seat Tube |
Featuring a low center of gravity frame combined with a wide 560mm handlebar, the Alpha effortlessly navigates turns with precision and stability. To assist young legs in tackling uphill challenges, the Alpha provides ample climbing capability with its 8-speed gearing system, offering a wide gear range. Its Microshift trigger shifter is specifically designed for smaller hands, making gear changes exceptionally easy. This attention to detail makes it a top contender in the 20 mountain bike category.
With the Alpha’s latest update, it now accommodates tires up to 2.1″ wide. This design enhancement is significant, as wider tires can provide improved cushioning and traction as kids progress in their mountain biking skills, further enhancing the bike’s trail readiness as a 20 inch mountain bike.
20 INCH MOUNTAIN BIKES – For Intermediate and Advanced Riders
If your child is progressing to intermediate blue trails, a more advanced and capable 20 inch mountain bike can significantly enhance their enjoyment, performance, and safety on the trail.
Beyond build quality, the key features that differentiate “beginner” bikes from “intermediate or advanced” bikes are:
(1) More aggressive geometry (slacker head tube angles) for better downhill control.
(2) Wide, cushioning tires for enhanced traction and comfort.
(3) Powerful and responsive disc brakes for reliable stopping power.
(4) Optional suspension fork to absorb impacts on rough terrain.
The ideal bike for your child truly depends on their intended use. For shuttle runs and lift-assisted riding, the added weight of a suspension fork can be quickly justified by the performance benefits. Conversely, this extra weight can hinder young riders already working hard on climbs. Choosing the right 20 mountain bike involves considering these trade-offs.
If you’re uncertain, consider what your child currently (or is likely to) complain about most while riding. If climbing is their primary struggle, a lightweight rigid bike with a less slack head tube angle will significantly aid their climbing ability over time (though you might still need to assist them on particularly steep or long inclines!). If they more often complain about being bounced around excessively on the bike, or about hand and arm fatigue, then a bike equipped with a quality suspension fork is likely a worthwhile upgrade.
Regardless of whether you opt for a suspension fork, pay close attention to head tube angles. The slacker geometry of the Prevelo Zulu with a 66° head tube angle offers exceptional confidence and stability for downhill sections. However, the 69.5° head tube angle of the Pello Rover will excel on climbs. Considering our primary testing grounds are the 10,000+ ft. Wasatch mountain range in Utah, we generally prioritize uphill performance, but your local terrain and riding style might dictate a different preference when selecting a 20 inch mountain bike.
Quality at a Good Price!
The Commencal Ramones 20 inch mountain bike, pictured in a studio shot, emphasizes its quality components and trail-ready design, making it a standout choice for young riders seeking performance without breaking the bank.
Commencal Ramones 20
$540
BEST FOR: Young groms on a mid-range budget eager to tackle true single-track trails on a capable 20 mountain bike.
View on Ready, Set, Pedal
Our 24″ Review
About the Commencal Ramones
The Commencal Ramones 20 is a fantastic, trail-ready 20 inch mountain bike that delivers excellent performance without a hefty price tag. Equipped with mechanical disc brakes, solid MTB geometry, and wide, knobby tires, the Ramones is a top recommendation for mountain biking families on a budget.
| Commencal Ramones 20 |
|---|
| MSRP |
| Weight |
| Seat Height |
| Tire Width |
| Max Tire Width |
| Gearing |
| Cassette |
| Brakes |
| Fork |
| Head Tube |
| Seat Tube |
A key differentiator at higher price points for mountain bikes is reduced weight. However, at this price point, the Ramones is notably lighter than many competitors. For young riders, a few pounds of weight reduction can make a significant difference, especially when tackling climbs, making the Ramones a smart choice for a 20 mountain bike.
Lightweight and Nimble
A young girl perched on her woom OFF 4 20 inch mountain bike, ready to descend a trail, highlighting the bike’s lightweight construction and downhill-oriented features perfect for adventurous young riders.
woom OFF and OFF AIR
$849 – $1,099
BEST FOR: Young groms with a mid-range budget ready to explore true single-track trails on a high-performance 20 mountain bike.
View on woom
OFF Review
OFF AIR Review
About the woom OFF and OFF AIR
The sole difference between the woom OFF and the woom OFF AIR is the suspension fork. The air fork on the OFF AIR model is specifically engineered for young, lightweight riders, featuring 60 mm of travel with adjustable rebound and lockout. Notably, woom’s air fork can also be purchased separately as a later upgrade if desired, making both great 20 inch mountain bike options.
| OFF 4 | OFF AIR 4 |
|---|---|
| MSRP | $849 |
| Weight | 18.5 lb. |
| Seat Height | 22.8″ – 28.7″ |
| Tire Width | 2.35″ |
| Gearing | 9 speed, SRAM trigger |
| Brakes | Hydraulic disc |
| Fork | Rigid |
| Head Tube | 68° |
| Seat Tube | 70° |
If budget were unlimited (though in the world of high-end bikes, it rarely is!), we would recommend every young beginner start their mountain biking journey on a woom OFF 4, particularly those facing hilly terrain. Why? Because 4 to 7-year-olds on a 20 inch mountain bike are incredibly light. For a bike to perform optimally for their small frames, it must be exceptionally lightweight.
Consider this: if a 5-year-old weighs 50 pounds, a 22-pound bike (while already light!) still constitutes 44% of their body weight. At just 18.5 pounds, the woom OFF reduces this to only 37% of the child’s body weight. This significant difference in weight percentage dramatically impacts a child’s ability to handle the bike, especially uphill, making the woom OFF a standout 20 mountain bike for young riders.
Imagine trying to haul a bike that’s 44% of your own body weight up a hill! Adding to the challenge, 4 to 7-year-olds lack the mental and physical stamina for long rides or climbs, so they need every possible advantage.
Beyond its lightweight design, the woom OFF package is complete with hydraulic disc brakes, SRAM trigger shifters, and 2.25″ wide, cushioning off-road tires. For beginner to intermediate riders, the woom OFF is the ideal tool for developing their mountain biking skills.
When should you consider upgrading to the woom OFF AIR? If your young ripper is focused on catching air, or if you plan to engage in lift-assisted or shuttled rides, the AIR is a worthwhile upgrade. While the 2.5 pounds added by the suspension fork is noticeable, if your child spends more time descending than climbing, the suspension fork’s benefits justify the investment. (The only lighter 20″ hardtail with suspension is the Trailcraft Blue Sky 20.)
For riders needing extra cushioning on rough trails, while front suspension can be beneficial, simply reducing the PSI in the front tire can achieve a similar cushioning effect without the added weight and cost of a suspension fork on a 20 inch mountain bike.
Lightweight and Versatile
A young child confidently rides the Pello Rover 20 inch mountain bike on a dirt trail, demonstrating its versatility and lightweight design suitable for both on and off-road adventures.
Pello Rover
$589 – $688
BEST FOR: Young groms with a mid-range budget ready to tackle true single-track trails and seeking a versatile 20 mountain bike.
About the Pello Rover
The Pello Rover is offered with or without suspension. If you opt for the suspension fork, the rigid fork is also included at no extra cost. At checkout, you can choose to have the Rover shipped with the suspension fork pre-installed and the rigid fork in the box, or vice versa, providing flexibility in setting up your 20 inch mountain bike.
However, the optional fork on the Rover is a coil fork, which is not as responsive or adjustable as an air fork. Consequently, if your child truly requires suspension (though most in this age group don’t – see our suspension section below for reasons why), you might consider a more significant investment in a bike like the woom OFF AIR with its superior air fork.
| Rover | Rover w/ Suspension |
|---|---|
| MSRP | $589 |
| Weight | 19.9 lb. |
| Seat Height | 22.5″ – 27.5 |
| Tire Width | 1.95″ |
| Max Tire Width | 2.1″ front, 1.95″ rear |
| Gearing | 7 speed, SRAM trigger |
| Cassette | 11-34T |
| Brakes | Mechanical disc |
| Fork | Rigid |
| Head Tube | 69.5° |
| Seat Tube | 72° |
The Rover stands out as the Goldilocks of 20 inch mountain bikes, offering just the right level of technical components for advancing intermediate riders. Standard features include a lightweight frame with a low center of gravity, trigger shifters, and mechanical disc brakes. The Rover provides everything a young rider needs to confidently tackle blue trails without the added expense of unnecessary “nice-to-haves.” Furthermore, the Rover comes with a very reasonable price tag, making it an accessible 20 mountain bike for many families.
As your child’s skills progress, the Rover can evolve with them. Beyond adding a suspension fork, you can upgrade to wider 2.1″ cushioning knobby mountain bike tires for enhanced traction and comfort – a step up from the standard 1.95″ all-terrain tires. This adaptability makes the Rover a lasting choice as a 20 inch mountain bike.
Who is the Rover not ideal for? While we highly appreciate the Rover for its exceptional performance across a wide range of riders, for dedicated downhill enthusiasts, the enhanced downhill stability offered by slacker head tube angles, like those found on the woom OFF and Zulu, might be more beneficial.
Best Overall
A child confidently rides a Prevelo Zulu Three 20 inch mountain bike over a rock slab, demonstrating the bike’s robust design and capability to handle challenging trail features with ease.
Prevelo Zulu Three
$1,199
BEST FOR: Young groms riding true single track, its low gear range makes it exceptional for tackling significant elevation changes on a 20 mountain bike.
About the Prevelo Zulu
The Prevelo Zulu Three has been updated for 2024 and is better than ever! We are scheduled to test this new model in June, but have updated the specifications here to reflect the latest model. The Zulu series is known for creating some of the best 20 inch mountain bike options for serious young riders.
| Zulu Three |
|---|
| MSRP |
| Weight |
| Seat Height |
| Tire Width |
| Gearing |
| Brakes |
| Fork |
| Head Tube |
| Seat Tube |
If you are fortunate enough to have a young grom eager to tackle challenging intermediate trails without hesitation, the Prevelo Zulu Three is an essential addition to your stable of bikes. For true downhill trail riders, you would be hard-pressed to find a kids’ 20″ all-mountain bike as thoughtfully designed and capable as the Zulu.
Featuring a slack 66° head tube angle, an 882 mm wheelbase, 80 mm of travel on an adjustable air suspension fork, hydraulic disc brakes, and dropper post compatibility, the Zulu is remarkably capable on descents. Whether navigating through rocky gardens or hitting jump lines, the Zulu maintains composure and delivers confidence-inspiring performance as a top-tier 20 inch mountain bike.
When climbing uphill or riding on generally flat trails with mixed terrain, the Zulu’s steeper seat tube angle optimally positions the rider over the pedals, maximizing pedaling efficiency and power transfer.
The newest 2024 Zulu has shed several pounds and now weighs just 20.5 pounds without pedals – only 0.2 lbs. heavier than the woom OFF AIR! This weight reduction enhances its agility and climbing prowess, further solidifying its position as a leading 20 mountain bike.
Most Customizable
A young rider descends a singletrack trail on a Trailcraft Blue Sky 20 inch mountain bike, highlighting its lightweight frame and customizable components, perfect for serious young mountain bikers.
Trailcraft Blue Sky 20
$999+
BEST FOR: Established groms seeking a customized pony, where nearly every component from gearing to suspension can be tailored to preference on this premium 20 mountain bike.
About the Trailcraft Blue Sky
The Trailcraft Blue Sky 20 is available in two models: the standard Special and the upgraded Pro. The Pro version is approximately 1.5 pounds lighter and features even higher-end components than the Special, making it an exceptionally lightweight 20 inch mountain bike.
| Blue Sky Special | Blue Sky Pro |
|---|---|
| MSRP | Varies |
| Weight | 20.5 lb. |
| Seat Height | 23″ – 28.6″ |
| Tire Width | 2.2″ tubeless ready |
| Gearing | 10-speed, Microshift trigger |
| Brakes | Hydraulic disc |
| Fork | Air w/ 80mm travel, adjustable rebound |
| Head Tube | 68° |
| Seat Tube | 73° |
The primary reasons to invest significantly more in a Trailcraft bike are its exceptionally low weight and extensive customizability. The value of these features is a personal decision. For riders seeking the ultimate in performance and personalization in a 20 mountain bike, Trailcraft is the brand to consider.
The Pro build of the Blue Sky is two pounds lighter than the woom OFF AIR. While two pounds might seem minimal, for a 5-year-old tackling hills, this weight difference can noticeably impact their desire and ability to keep pushing. We observed this positive impact firsthand with our 5.5-year-old aggressive tester, highlighting the real-world benefits of a lightweight 20 inch mountain bike.
If component selection is a priority, Trailcraft is the leading kids’ brand for customization. Beyond choosing chainring sizes, drivetrain, and braking components, all Blue Sky models are tubeless-ready and can even be shipped pre-converted to tubeless setups. Dropper post compatibility is also standard, offering advanced features typically found on adult bikes in a 20 mountain bike package.
If the standard component offerings on the Trailcraft site don’t align with your dream build, you can collaborate directly with the owners to further customize your bike. As a small, custom shop, Trailcraft offers a level of personalized service and flexibility that larger brands cannot match, making it possible to create a truly unique 20 inch mountain bike.
20 Inch Mountain Bikes to Keep on Your Radar
While not making our top 10 list, these 20 mountain bikes are still worthy of consideration.
Super Aggressive Geometry
A young child rides a Specialized Riprock 24 inch mountain bike, showcasing its aggressive geometry and robust tires, designed for adventurous young riders tackling challenging terrain.
Specialized Riprock 20
$600
BEST FOR: Aggressive young riders who prioritize downhill performance and need a robust 20 mountain bike.
View on Specialized
Our Review
About the Riprock
The Specialized Riprock is designed as a fast, fun, and ambitious pony tailored for the most aggressive young riders. While the Riprock boasts impressive components, including hydraulic disc brakes, trigger shifters, and wide 2.35″ cushioning tires, its exceptionally aggressive geometry presents some fit challenges.
The Riprock 20’s low stack height, extra-wide handlebars, minimal-rise stem, and high seat placement create a very narrow window for optimal rider fit. We hope to see a revision of the Riprock’s geometry in future models. Until then, recommending it broadly is difficult. For a detailed explanation and visual examples, be sure to read our full review to better understand if this 20 inch mountain bike is suitable for your child.
| Specialized Riprock |
|---|
| MSRP |
| Weight |
| Seat Height |
| Tire Width |
| Max Tire Width |
| Gearing |
| Brakes |
| Fork |
| Head Tube Angle |
| Seat Tube Angle |
However, for those aggressive young groms who find the Riprock a good fit, it is sure to deliver an incredibly addictive and thrilling ride. Even without a suspension fork, the Specialized Ground Control tires, when properly inflated, provide ample cushioning and traction for challenging rock gardens and small drops, making it a capable 20 mountain bike in the right hands.
Heavy
A 7-year-old rides the REI REV 20 6-speed bike on a wide dirt trail, showcasing its approachable design for casual trail riding, though its weight might be a limiting factor for more serious mountain biking.
REI Co-Op REV Plus 20
$399
BEST FOR: Families seeking a versatile 20 mountain bike for light trails and general use, but not ideal for serious mountain biking due to its weight.
About the REV Plus
The REI Co-Op REV Plus 20 is another bike we appreciate for many reasons, but we don’t consider it optimal for true mountain biking. While its mid-fat tires give it a rugged appearance, the bike is heavy – weighing in at 25 pounds without a suspension fork.
While you could mountain bike with the REV Plus 20 if your budget dictates, most children would be better served by the lighter and more affordable Polygon Ultralight (20.75 pounds). Alternatively, if you can extend your budget by a few hundred dollars, you could get trigger shifters and a lighter overall bike with the Prevelo Alpha Three (19.1 pounds) or Commencal Ramones 20 (23.5 pounds). These lighter alternatives offer enhanced performance as true 20 inch mountain bikes.
What to Look For When Choosing a 20 Inch Mountain Bike
20 inch mountain bikes occupy a unique space – they are still very much “kids’ bikes,” yet need to perform like adult mountain bikes on trails. Simply scaling down an adult mountain bike to kid-size proportions seems straightforward but can quickly lead to compromises in functionality and performance.
Children’s body proportions differ from adults, and crucially, they weigh significantly less. Consequently, bike weight becomes a paramount factor in the cost-benefit analysis of every component on a 20 mountain bike.
On most adult mountain bikes, adding more features is generally desirable because the added weight is negligible compared to the increased functionality. However, with small 20 inch mountain bikes, the opposite often holds true. Weight is king, and optional components (like suspension forks, dropper posts, etc.) should be considered cautiously to ensure they truly enhance, rather than hinder, the riding experience.
From tires to brakes, we will guide you through what features are truly essential and what you can skip when selecting a mountain bike for your son or daughter, helping you make the best decision for a 20 inch mountain bike.
Weight – The Most Critical Factor for a 20 Mountain Bike
As previously emphasized, for young riders hitting trails, a lightweight bike is absolutely critical. While older, heavier, and more experienced riders can manage heavier bikes, most kids on 20 inch mountain bikes don’t fit this profile. For 20 inch riders, lightweight basic trail bikes are often more advantageous for skill development than heavier, more feature-rich advanced bikes.
For example, consider our 6-year-old child weighing 50 pounds. The 24-pound REI Co-Op Plus represents 48% of his body weight. We tested and appreciated the Co-Op bike, but despite its wide off-road tires and disc brakes, its weight made it impractical for any extended trail rides with climbs. In contrast, on the same trails, the 19-pound Prevelo Alpha (38% of his body weight) performed significantly better, even with narrower all-terrain tires and V-brakes. This comparison underscores the importance of weight in a 20 mountain bike.
Therefore, even if you envision your child confidently tackling challenging trails on a mini-enduro style 20 inch bike, we strongly recommend starting them on a lightweight bike with fewer features. Then, as their skills and strength progress, you can transition them to a more advanced bike when they are truly ready. This approach not only aids in learning essential riding techniques but also ensures your child is prepared for a more aggressive (and often more expensive) setup, making their journey into mountain biking more enjoyable and successful on a properly chosen 20 mountain bike.
Tires – Balancing Terrain and Performance on a 20 Inch Mountain Bike
A side-by-side comparison of tire treads on a 16 inch mountain bike, showcasing a 1.5″ all-terrain tire versus a 2.1″ off-road tire, illustrating the difference in tread patterns and widths suitable for varying terrains.
1.5″ all-terrain tire vs. 2.1″ off-road tire
The optimal tire for your child’s 20 mountain bike depends on the terrain they will be riding most frequently. While wider, off-road tires generally offer superior performance for mountain biking, they aren’t always the best choice for every rider or situation.
Beginner riders often perform well with quality all-terrain tires, such as the popular Kenda Small Block 8 found on the Prevelo Alpha and Polygon Ultralight. We have had several testers successfully complete mountain bike skills classes using Small Block 8’s without issue. Their lower rolling resistance and lighter weight contribute to a nimble feel on climbs while still providing adequate traction for descents. These tires make 20 inch mountain bikes more versatile for mixed-terrain riding.
Once young riders become more confident leaning into turns aggressively or tackling rougher trail sections at higher speeds, the added cushioning and traction of wider, beefier tires become invaluable. When inflated to a lower PSI, wider tires on a 20″ MTB can provide a cushioning effect comparable to some suspension forks, enhancing comfort and control.
For our rapidly growing testers, the upgrade often involved transitioning to a larger 24″ bike (kids can outgrow 20 inch bikes quickly!). However, for smaller riders, we simply swapped the tires on their 20″ bike to wider, knobby tires, such as these 1.9″ Schwalbe Black Jacks. This simple tire upgrade can significantly transform a 20 mountain bike‘s trail capability.
Suspension Fork – To Suspend or Not to Suspend on a 20 Inch Mountain Bike
Contrary to popular belief, our extensive testing has shown that most children on 20 inch mountain bikes benefit more from a rigid bike than one with suspension. Why? The added weight of a suspension fork often outweighs the limited benefits it provides to lighter riders. This is a crucial consideration when choosing a 20 mountain bike.
Children riding 20 inch bikes weigh relatively little, so a suspension fork must be finely tuned to react effectively to the minimal pressure exerted by these lightweight riders. In the past, quality forks capable of performing under these conditions were scarce. Suspension forks on 20-inch bikes were often more for show than practical function.
A visual comparison of a woom OFF AIR suspension fork versus a woom OFF with a rigid fork on a 20 inch mountain bike, highlighting the difference in fork design and the implications for weight and performance.
Suspension vs. Rigid Fork
In recent years, several high-quality suspension forks have been developed specifically for young children. However, these forks are typically very expensive. In almost all cases, it is more effective to invest in a lightweight rigid bike with wider, cushioning tires (inflated to a lower PSI) than to choose a bike of similar price that is heavier and equipped with front suspension. This approach often yields better overall performance for a 20 mountain bike.
Reasons to consider a 20 inch mountain bike with a suspension fork:
- Your child is riding frequently and intensely enough on rough terrain that they experience hand or arm numbness.
- Your child’s bike cannot accommodate extra-wide 2.1″+ tires, especially on the front, inflated to a low PSI. Wide, cushioning tires on a 20″ MTB can often provide a similar level of cushioning as many suspension forks.
- Their rides are predominantly downhill-focused (shuttle rides, lift-assisted trails, frequent tow rope use).
- AND (not OR) You have the budget to invest in a high-end bike ($900+) equipped with a quality, performance-oriented suspension fork. For these specific scenarios, a suspension fork might be a valuable addition to a 20 inch mountain bike.
Reasons to avoid a 20-inch mountain bike with a suspension fork:
- You believe they need one based on assumption rather than the child demonstrating a genuine need.
- You are drawn to the aesthetic appeal of a suspension fork, rather than its functional benefits for your child’s riding style and terrain.
If you are uncertain whether your young rider needs a suspension fork, we highly recommend starting with the woom OFF or the more budget-friendly Pello Rover. The Pello Rover with suspension option thoughtfully includes both a suspension fork and a rigid fork. This allows you to begin with the rigid fork setup and transition to the suspension fork later if your child shows a clear need. However, note that the suspension fork on the Rover is a coil fork and not as responsive as the air fork found on the woom OFF AIR. This versatility makes the Pello Rover a practical choice when considering suspension for a 20 inch mountain bike.
While the woom OFF AIR does not include a rigid fork, the suspension fork for the woom OFF can be purchased separately as an upgrade at a later time. This modular approach provides flexibility and allows for performance enhancements as your child’s skills and riding demands evolve with their 20 mountain bike.
Gears or Single Speed? – Gearing Up for Trails on a 20 Inch Mountain Bike
Unless your riding is limited to smooth, simple dirt trails around your neighborhood, basic downhill runs (like being dropped off at the top and just riding down), or pump track laps, your child’s 20 inch mountain bike absolutely needs gears.
A minimum of 6 gears is necessary for true trail riding. If you anticipate significant elevation changes in your rides, a wider gearing range is even more beneficial. Regardless of the number of gears, we strongly advise getting a tow rope for any 20 inch mountain bike. Tow ropes are invaluable for assisting with long ascents or when young riders encounter fatigue, making family mountain biking outings more enjoyable and manageable.
Trigger vs. Grip Shifter – Shifting Preferences on a 20 Mountain Bike
For more aggressive trail riding, trigger shifters are unequivocally superior to grip shifters. Trigger shifters allow for quicker and more precise gear changes. They also prevent accidental handlebar twisting during shifting, which can be a common issue with grip shifters, especially for younger riders. This responsiveness is crucial for maintaining control on a 20 inch mountain bike on varied terrain.
As your child’s riding progresses, many bikes originally equipped with grip shifters can be fairly easily upgraded to trigger shifters. You will need to purchase a trigger shifter set that matches the number of gears on your bike, such as this 7-speed trigger shifter, along with new grips. This bike mechanic’s video provides a helpful demonstration of the conversion process. This upgrade can significantly enhance the performance and usability of a 20 mountain bike.
While trigger shifters offer performance advantages, they can initially be more complex for very young children to learn compared to grip shifters. To aid in the learning process, we recommend using colored stickers on the trigger shifter levers. When teaching your child to shift, ride behind them and verbally guide them by calling out the color of the button they should press. This visual and verbal cue method can simplify the learning curve for using trigger shifters on their 20 inch mountain bike.
Brakes – Do You Need Disc Brakes on a 20 Inch Mountain Bike?
All mountain bikes, including 20 inch mountain bikes, must have reliable, high-performing brakes with ample stopping power. If your child primarily rides basic green trails, high-quality v-pull brakes are sufficient. However, as your child advances to intermediate blue trails and beyond, the enhanced stopping power of disc brakes becomes increasingly valuable.
A close-up comparison showing a v-pull brake alongside a disc brake system, illustrating the differences in their mechanisms and highlighting the superior stopping power and modulation of disc brakes, essential for mountain biking.
Hydraulic disc brakes represent the pinnacle of braking technology, offering superior modulation (allowing riders to finely control braking force) and reducing hand fatigue, particularly on long descents. Mechanical disc brakes provide greater stopping power than v-pull rim brakes but lack the same level of modulation as hydraulic systems. Both types of disc brakes are a significant upgrade for a 20 inch mountain bike used on challenging trails.
Mechanical disc brakes can be upgraded to hydraulic disc brakes relatively easily. However, upgrading from v-pull brakes to disc brakes is generally not feasible because it requires frame modifications. Therefore, if you anticipate your child progressing to more demanding trails, choosing a 20 mountain bike with disc brakes from the outset is a wise investment.
Geometry – Finding the Right Fit for Young Riders on 20 Inch Mountain Bikes
The ideal geometry for your child’s 20 inch mountain bike largely depends on the amount of climbing they will be doing. Kids on 20 inch bikes are in a transitional phase—they are past needing to be towed uphill constantly (like riders on 16″ bikes), but they still lack the stamina and muscle strength to power up trails like older kids on 24″ bikes. Balancing climbing efficiency and downhill capability is key when considering 20 mountain bike geometry.
While assisting your child uphill with a tow rope is sometimes necessary and beneficial, you also want to foster their ability to climb independently and build both physical and mental endurance. For most children, 20 inch mountain bikes with head tube angles in the 68° – 70° range strike an optimal balance for both climbing and descending.
This isn’t to say that slacker bikes (66° – 67° head tube angles), designed more for downhill performance, are without merit. For experienced young riders who are motivated to conquer uphill sections to enjoy the rewards of downhill riding, slacker bikes are an excellent choice. If your riding plans include shuttled runs or lift-assisted trails, a slacker 20 inch mountain bike is definitely worth considering.
A side-by-side geometry comparison diagram of the Pello Rover (69° HTA) versus the Prevelo Zulu Three (66° HTA) 20 inch mountain bikes, illustrating the difference in head tube angles and their impact on riding characteristics.
Pello Rover (69° HTA) vs. Prevelo Zulu Three (66° HTA)
What is the head tube angle (HTA) of a bike? The head tube angle significantly influences the positioning of the front tire relative to the bike frame. A more forward front tire position results in a “slacker” bike, while a closer position makes the bike “less slack.” Head tube angle is a critical factor in the handling and stability of a 20 inch mountain bike.
Due to the unique challenges of fitting a small child’s body onto a bike with modern geometry, what’s considered “slack” for a 20 inch bike differs somewhat from adult bikes. After evaluating major kids’ bike brands (including Spawn, Trailcraft, Specialized, Commencal, Prevelo, woom, etc.), the slackest head tube angle we found was 66° on the Prevelo Zulu. 68° is a common head tube angle, while “all-around” geometries typically range from 69° to 70°.
Our preference for mountain bikes with steeper head tube angles (higher numbers) is because they facilitate easier climbing. On “slacker” bikes, the more forward wheel position reduces the weight distribution on the front wheel. Consequently, during steep climbs, the front tire can lose traction if the rider doesn’t actively lean forward to increase weight on the front wheel. This is an important consideration for 20 mountain bike geometry.
While adult riders quickly learn to adjust their body position to lean forward while climbing, young riders are often preoccupied with other aspects of riding and may forget to lean forward sufficiently. Bikes with “less slack” head tubes position the front tire closer to the bike, naturally placing more of the child’s weight over the front tire. This design element makes climbing more intuitive and efficient for young riders on a 20 inch mountain bike.
Girls and Boys 20 inch Mountain Bikes – Gender Neutrality in Design
A young girl sits proudly on her bike, wearing SHREDLY Littles Collection apparel, showcasing the gender-neutral design of kids’ mountain bikes and the focus on performance and fit over gender-specific features.
Baby Ripper Wearing SHREDLY Littles Collection
Is a girls’ 20 inch mountain bike different from a boys’ 20 inch mountain bike? No. All kids’ mountain bikes are essentially gender-neutral. A child’s skill level, size, and weight are far more relevant factors in selecting the best bike than their gender. Some brands offer color options that are traditionally marketed as feminine, such as pink or purple. However, these are purely aesthetic choices and do not affect the bike’s performance or suitability as a 20 mountain bike for any child.
You can also outfit your young female rider in stylish and functional SHREDLY MTB gear for girls (as seen above) to personalize their riding experience. Ultimately, the best 20 inch mountain bike is one that fits well, suits the child’s riding style and abilities, and encourages a love for mountain biking, regardless of gender.
