Woom OFF & Woom OFF AIR Kids Mountain Bike Review

For years, we’ve heard Woom-loving parents complain when it came time to switch their child to a real mountain bike. “Why doesn’t Woom offer a mountain bike!?!?” they’d ask.

If that was you, it’s time to cheer. Woom recently released a new line of mountain bikes: the Woom OFF and the Woom OFF AIR. These bikes come in 20″, 24″, and 26″ wheel options, and with either a rigid carbon fork (Woom OFF) or a suspension fork (Woom OFF AIR).

The Woom OFF is well-positioned as a high-quality kids mountain bike that won’t break the bank. Like all Woom bikes, it’s incredibly lightweight, comes with well-designed child-specific geometry, and includes top-shelf components.

The Woom OFF with rigid carbon fork is a great choice for families that primarily stick to smooth dirt trails, and those who want to prioritize weight. The Woom OFF AIR, on the other hand, is the perfect choice for hard-charging kids riding more technical trails.

Both bikes are some of the best capable LIGHTWEIGHT mountain bike options available for kids. And they are ones that won’t make you take out a second mortgage on the house.

woom off in action

Review in a Nutshell


  • Super lightweight
  • High volume tires
  • Hydraulic disc brakes
  • Thru-axles both front and rear
  • Carbon fork OR suspension fork
  • Good bang for your buck


  • Wheels aren’t tubeless ready
  • Externally-routed cables
  • No quick-release seatpost collar

Price (Woom OFF): $799-$899
Price (Woom OFF AIR): $949-$1,049

Woom OFF Video Review

Woom OFF AIR Video Review

Option #1: Carbon Fork

woom OFF carbon fork

The cheapest (and lightest) option is to choose the Woom OFF with rigid carbon fork. The carbon fork does a good job of absorbing vibration and chatter from the trail.

If your child is currently on a fully-rigid 16-inch bike, the carbon fork (along with high-volume tires which we’ll discuss in a moment) will make a noticeable difference in their enjoyment on rocky or rough trails. Contrasted to most rigid bikes, where our son has to frequently stop to shake out his hands, he didn’t complain about hand numbness or arm pump on the Woom OFF.

That said, he WAS noticeably slower on technical terrain on the Woom OFF than on the Woom OFF AIR (with suspension fork). His confidence on drops and techy terrain was also noticeably impacted on the Woom OFF.

So why would Woom offer the OFF with a rigid fork? Probably three notable reasons.

First, a rigid fork weighs significantly less than a suspension fork, and weight on kids bikes is key. Secondly, by offering a rigid fork, they are able to offer the bike at a more reasonable price point (as in a couple of hundred dollars less). Finally, most kids simply don’t NEED a suspension fork. If your family rides rugged or technical terrain OR your family is super serious about mountain biking, yes, spend more to buy your child a HIGH-QUALITY suspension fork.

woom off on technical trails

Otherwise, if your family rides primarily smooth, relatively mellow trails, the carbon fork on the Woom OFF will perform beautifully. We should also note that if you are on a budget, and can’t afford an expensive high-quality air fork, your child is much better off on a rigid carbon fork than they are on a heavy, cheap coil-sprung suspension fork.

Option #2: Suspension Fork

Woom OFF AIR suspension fork

The suspension fork on the Woom OFF AIR is a high-quality air fork made for Woom by RST. We’ve found that it’s plush, engages easily, and provides plenty of travel for most types of riding.

The fork has adjustable pressure so you can set it up properly for the weight of your child. This was quick and easy to get dialed in, but it does require a shock pump (not included).

There is also adjustable rebound and a lockout switch. I found that my son used the lockout for longer climbs, and then opened it up for the descents. It was easy for him to operate on his own.

In terms of travel, the bike boasts 60mm, 80mm, or 90mm for the 20″, 24″, and 26″ versions respectively. This is plenty of squish for most types of riding including rocky and rooty trails.

That said, if your child is going to be taking big drops or doing more gravity-oriented riding, you may opt to look for a bike with more travel.

For comparison, in terms of 20 inch mountain bikes, both the Trailfcraft Blue Sky 20 and the Prevelo Zulu Three HEIR mountain bikes have 80mm of travel, while the Spawn Rokkusuta 20 has a whopping 100mm of travel. Most kids don’t need a big-travel bike like the Rokkusuta, but just be aware that the Woom OFF Air is on the lower end of the suspension spectrum when compared to high-end kids mountain bikes. The forks on those bikes also have features like carbon lowers that the Woom fork does not.

Still a better (and more fair) comparison be to the “average” kids “mountain bike.” Most kids mountain bikes on the market (like the Trek Precaliber*, for example) have coil-sprung forks. These cheaper forks are heavy, aren’t adjustable, and have poor compression and rebound. The quality air fork on the Woom OFF AIR is heads-and-shoulders above those found on cheaper, inferior kids mountain bikes.

So, we’ve established that the suspension fork on the Woom OFF AIR is rad. But, is there any reason NOT to opt for the Woom OFF AIR over the Woom OFF?

Yes, in fact there are two.

The suspension fork adds both weight and expense. It adds $200 to the pricetag and a couple of pounds of heft.

Still, thanks to the added comfort and technical prowess, we’d highly recommend the suspension fork over the rigid fork unless you’re on a strict budget OR your family plans to stick to mellow trails.

woom off air 4 20 inch mountain bike

High-Volume Tires Increase Traction and Comfort

The Schwalbe Rocket Ron tires are high-volume which also helps absorb some vibration and provide a plusher ride compared to skinnier tires. The wide tires also do a good job of rolling over obstacles and maintaining traction.

The only thing that would be even better is if the wheels and tires were set up tubeless, so they could be run at a lower psi.

We did have one community member ask us how wide of tires could be added to the Woom OFF. While we haven’t tried swapping out tires (yet), I measured the clearance and am fairly confident that on the Woom OFF 4 you could run a tire as wide as 2.5″. (It currently has a 2.25″ tire installed).

Hydraulic Disc Brakes Offer Superior Stopping Power

If your child has been riding a 16-inch bike with v-brakes prepare to be amazed at how much of a difference hydraulic disc brakes can make. Your child will be able to stop faster, modulate their braking, and skid less.

Additionally, hydraulic disc brakes are easier for little hands to operate. Kids won’t experience braking fatigue with the Promax brakes on the Woom 4. The levers are easy for small hands to reach and operate. My son mentioned several times that he liked the brakes on this bike.

SRAM 1×9 Drivetrain

The SRAM trigger shifter on the Woom OFF is superior, in our opinion, to the grip-shifter found on the standard Woom 4/Woom5/Woom 6. My son, who tests a lot of bikes for us, said that the shifter was easy for him to operate.

The only issue is that the trigger shifter does not have any sort of display, which may make it challenging for kids who haven’t already learned to shift. If your kiddo is coming from a bike with gears already, they should be fine with this setup.

The SRAM X5 derraileur was clean shifting. Although it doesn’t have a clutch, we haven’t experienced any issues with a dropped chain.

The 1×9 drivetrain provides a good range of gears while keeping things simple. For the bike geeks out there, here are the gear and gain ratios. (I’m not claiming to be that good at math here, so feel free to double-check my calculations).

  • On the Woom 4 OFF, the front chainring has 28T and the rear cassette ranges from 11 to 32T. This equates to a gear ratio between 0.88 and 2.55, or a gain ratio of between 2.47 and 7.19.
  • On the Woom 5 OFF, the front chainring has 28T and the rear cassette ranges from 11 to 34T. This equates to a gear ratio between 0.88 and 2.55, or a gain ratio of between 2.12 and 6.55.
  • On the Woom 6 OFF, the front chainring has 28T and the rear cassette ranges from 11 to 36T. This equates to a gear ratio between 0.8 and 2.55, or a gain ration of between 1.87 and 6.11.
gain ratio calculations

Thru-Axles Provide Stability and Safety

We were stoked to see that the Woom OFF features thru-axles on both the front and rear wheel (15mm front/12mm rear). Compared to old-fashioned quick-release skewers you’ll find on most kids bikes, thru-axles provide superior stability and they are safer. You don’t have to worry about a skewer rattling loose and backing out.

woom off disc brake

Lightweight Build Helps Kids Ride Further, Faster

Woom bikes are known for being the lightest kids bikes around, so we weren’t surprised to see that the Woom OFF 4 weighs in at a mere 17.2 lbs, while the Woom OFF AIR weighs 19.8 lbs. We weren’t surprised, but we were pleased.

Most kids mountain bikes are just SO HEAVY. Even bikes I really love, like the Prevelo Zulu, give me pause when I see how much kids struggle with them on big climbs. Lighter bikes are easier to ride (especially uphill) and easier to maneuver.

woom off cornering

On uphills (and flats), our son was flying on the Woom 4 OFF. He was able to climb better on it than any other 20-inch mountain bike we’ve tested. If you live in a mountainous area, or you have a particularly lightweight child, the weight of the Woom OFF is a serious attraction.

Modern, Mountain Bike Geometry

We like the bike’s slack, modern, mountain bike geometry. Although it would make a good bike for cross-country racing, it doesn’t have overly aggressive geometry. Kids are placed in a comfortable position on the bike.

The Woom OFF 4, for example, has a 68-degree steering angle and 70-degree seat tube angle. The headtube angle is nearly identical to other 20-inch mountain bikes like the Prevelo Zulu and Spawn Yama Jama. On the other hand, a seat-tube angle of 70 degrees is acceptable but mid-70s like those other bikes would be even better as it places kids in a better position for climbing and pedaling.

The Woom OFF bikes have a long wheelbase; the OFF 4 measures in at 35 inches wheel-to-wheel. This is comparable to other higher-end kids mountain bikes and indicates that the bike is nice and stable.

Finally, we appreciate the wide handlebars. The Woom OFF 4 has 580mm handlebars which provide for superior handling capability. The handlebars have 20mm of rise, but the flip-flop stem can be turned over to provide a more upright riding position or left downward to provide a more aggressive riding position. We left it in the downward position since my son felt comfortable with it there.

woom OFF stem

Possibly The Best Stock Pedals We’ve Seen

Pedals probably aren’t going to be the deciding factor when choosing a mountain bike, but we were excited about the pedals on the Woom OFF. In fact, we think they are the best stock pedals we’ve seen.

There are six metal pins on each side that do a good job of keeping little feet firmly planted on the pedals. Additionally, they aren’t bulky like many stock pedals. The profile is thin and narrow, and during testing, I didn’t notice my son have any pedal strikes.

woom off pedals

Narrow Q-Factor and Appropriate Crank Length

Many parents get caught up in the exciting parts of a bike build (suspension! brakes!) and forget the mundane, but important details like q-factor and crank length. We’ve seen plenty of promising bikes fail the test when it comes to crank length, in particular.

woom off front chainring

The cranks on all the Woom OFF bikes have been thoughtfully chosen. The cranks range from 110mm on the Woom 4 OFF to 150mm on the Woom 6 OFF.

The space between the cranks (the q-factor) is also appropriately narrow, which provides for an efficient and comfortable pedal stroke.

A Couple of Things We’d Improve

If this was our bike to design, there are a couple of things we’d change:

  • Cable routing. The derraileur and brake cables on the Woom OFF are externally-routed. Especially where this is a mountain bike, and your child is likely to be riding in dusty, dirty conditions, we’d like to see them be internally routed.
  • Seatpost collar. The Woom OFF doesn’t have a quick-release seatpost collar….which is actually pretty obnoxious. Again this is surprising since the other Woom bikes do. When mountain biking, we are constantly raising and lower our son’s seat. Putting the seat down on descents can be hugely helpful. (In fact, we have a dropper post on our son’s Trailcraft just to make this even faster/easier).

Woom OFF vs The Competition

To see comparison charts and compare the Woom OFF to other kids mountain bikes, check out these articles:

woom off air in action

Other Stuff Worth Mentioning

  • The saddle is ergonomic for little bodies and is for-aft adjustable.
  • While the bike only comes in one color (black), it does come with a sticker pack so you can customize your child’s bike with one of four different color decals. We did notice some bubbling/peeling of these stickers pretty early on though–kind of a bummer.
  • Grips. One thing I really liked on the bike are the grips, and I sort of want a pair for myself. They are a rubber-like material with lots of little holes. They are soft and grippy. I’m not sure how they will hold up over time, but we’ll update if there are issues.

Woom OFF Sizes

Woom 4 OFF – 20″


Price: $799 Weight: 17.2 lbs

Woom 5 OFF – 24″


Price: $849 Weight: 18.96 lbs

Woom 6 OFF – 26″


Price: $899 Weight: 20.94

Woom 4 OFF AIR


Price: $949 Weight: 19.8 lbs

Woom 5 OFF AIR


Price: $999 Weight: 22.3 lbs

Woom 6 OFF AIR


Price: $1,049 Weight: 24.3 lbs

Additional Woom OFF Specs / Geometry

Woom 4 OFFWoom 5 OFFWoom 6 OFF
Tires 20 x 2.25″ Schwalbe Rocket Ron 24 x 2.35″ Schwalbe Rocket Ron 26 x 2.35″ Schwalbe Rocket Ron
Axles100 x 15 mm front / 135 x 12 mm rear through-axles 100 x 15 mm front / 135 x 12 mm rear 100 x 15 mm front / 135 x 12 mm rear
Handlebar Width: 580 mm , Rise: 20 mmWidth: 600 mm, Rise: 20 mm Width: 680 mm – Rise: 20 mm
Crank Length110 mm 130 mm 150 mm
Rotor diameter 140/140mm  140/140mm 160/140mm
Headset Fully integrated 1″ – 1 1/8″ Fully integrated 1″ Fully integrated 1″
Seatpost 27.2 x 250 mm 27.2 x 250 mm 27.2 x 300 mm
Steering Angle68 degrees69 degrees69 degrees
Set Tube ANgle70 degrees70 degrees71 degrees

Bottom-Line: A Superior Choice For Budget and Weight Conscious Parents

Due to its lightweight build, the Woom OFF is a great option for petite kids, those who don’t need a suspension fork, and for all-around riding. The Woom OFF AIR is a capable trail bike capable of tackling rocky and rooty technical trails.

We also appreciate that both bikes comes in under $1,000 which helps keep it realistic for parents who can’t afford a more expensive bike like the Trailcraft or Prevelo Zulu HEIR.

More Help Choosing a Mountain Bike For Your Child

About The Reviewer

Kristen Bonkoski is the founder and owner of Rascal Rides. She’s an avid cyclist and loves all kinds of biking, but has a particular soft spot for mountain biking. Her favorite rides are those with her husband and son.

18 thoughts on “Woom OFF & Woom OFF AIR Kids Mountain Bike Review”

  1. Woom Specifications state
    Woom 4 OFF
    17.2 lbs (without pedals)
    Do you know what it weighs with pedals I called them they could not tell me.

    • Hi Alejandro,
      I did a quick search for you, and didn’t find them for sale after-market anywhere. You could always reach out to Woom and see if they would sell you a pair…

  2. I just received our Woom off 4 I had the same issue with the seat post scratching should have filed it first. Have you had issues with the black coating on the bike ours is scratching and marking very easily. It has a mat finish and doesn’t have any durability.

    • Hi Harry,
      Thanks for sharing your experience. I’m dissapointed to hear that. We haven’t had issues yet with the frame, but my son is pretty careful with it. I’ll definitely update my review if we run into the same problem….

  3. This may be very obvious, but I’m trying to compare the regular Woom 4 and the 4 Off for my 5 year old son. He’s a voracious rider, but we haven’t done too much truly rugged terrain–mostly gravel park trails and the like, though there are plenty of hills where we ride. He ripped through since 3 years on a Specialized and we picked up a cheap, in-the-moment yard sale find when he needed a larger bike last summer to hold place while we looked for a bigger, better investment bike. At what point would you say to move from the regular 4 to an Off? Is it hills? Riding surface? I admit, the price scares me, but I don’t want to buy a regular 4 and regret it…thank you!

    • Hi Lauren,
      Great questions. The vast majority of kids are going to be just fine on the regular Woom 4.
      Terrain/riding surface would be the determining factor. I would upgrade to the Woom OFF if he’s going to the pump track, wants to try riding some dirt singletrack trails, has expressed interest in doing a mountain bike camp, etc.
      For simple gravel rail trails and that sort of thing, the Woom 4 should be just fine….Hope that helps!

  4. Hi –
    Thanks for the amazing review. Can you tell me if the PNW Components Pine 27.2 Dropper Seatpost would work with the Woom Off?

  5. Good review, but believe one of your cons is wrong. External routing is 100x better as it’s soo much easier for maintenance and since it’s full cable housing won’t get muck/dust in, as well as being quiet compared to rattling internal cables.

  6. Hi there! Has anyone owned both the woom off air and the prevelo Zulu heir (upgraded model with Heir fork?
    looking at getting a 2018(?) prevelo Zulu 4 heir used for $800, which appears to be in pretty good condition.
    I also have a preorder on the woom off air 5. It looks like the prevelo heir has a much better drive train w/clutch, but is heavier and more slack – could anyone comment on the differences of the fork? Is the heir really much better? Anything else that would make the prevelo better or vice versa. Thanks!

  7. Hello,
    may I ask you about the length of cranks? Is 110 mm really enought for 20″ Woom 4 Off? The other 20″ bikes have about 125 mm.
    Our Early Rider Seeker 16 has 105 mm so I expect, that 20″ needs longer cranks that…

    What about Early Rider Seeker 20″? Have you tested it?


  8. Hello,

    may I ask you about the crank lenght on this Woom 4 Off 20″. Is 110 mm enought? The other 20″ bikes have about 125 mm.

    My son has Early Rider Seeker 16″ with 105 mm cranks, so I expect that 20″ bike should have longer cranks than 110 mm.

    What about 20″ Early Rider Seeker or Hellion? They are pretty lightweight too. Have you tested it?


  9. I have a woom 4-5-6 and we love the 4-5 but I can’t recommend the 6 for a handful of reasons but the biggest is the fact that the crank arms will bend and break off. The arms bent on my 10 year old son’s bike and one actually broke off resulting in an injury. I haven’t seen any issues on the 4 or 5 but I would say the arms are not cut out for the Woom off 6.


Leave a Comment