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ADULT BIKES

The Prevelo Bike Sizer 3000

What's the difference?

Balance bike: For riders who are using a balance bike without pedals.

Learning to pedal: The rider has never ridden a two-wheel pedal bike without assistance or training wheels, and is ready to learn to pedal. For new riders, we prioritize a slightly smaller fit to make learning easier and less intimidating.

Knows how to ride: The rider can pedal a two-wheel bike independently without assistance. For these riders, we prioritize a fit that balances comfort, control, and more efficient ergonomics.



Getting your kids the right size bike is important and, fortunately, also easy. You just need two pieces of information about your little rider:

  • Inseam
  • Rider Experience

Measuring Inseam

  1. Have the rider stand against a wall, hold a book between their legs so that it is firmly against their crotch  and the wall (the same place their bicycle seat will be).
  2. Measure the distance from the floor to the top of the book.
Prevelo Bike Inseam Kid

Rider Experience

Children who are learning are more sensitive to bicycle height than children who already know how to ride a bike. If the rider is new we recommend erring on the side of a smaller bike.  If the rider is experienced and confident, it is OK to err on the side of a larger bike.

Inseam vs. Height vs. Age

Inseam is the most reliable size indicator. If you don't have the rider's inseam, but know the rider's height you can use the rider's height to size a bike. We do not recommend sizing based on age. We include ride age as guidance for our bikes as a quick reference. But because riders of the same age can have very different sizes, inseam is a more reliable size indicator than age.

Riding Style

When riding dirt jump and pump tracks, like the Bravo Series is designed for, many riders are most comfortable on a slightly smaller bike. Many riders go to a smaller wheel size for Bravo Series bikes.

Shop by age

Age is a quick starting point. Pick your child's age for our recommended bikes, then confirm the fit with their inseam.

  1. 2 yrs
  2. 3 yrs
  3. 4 yrs
  4. 5 yrs
  5. 6-7 yrs
  6. 8-10 yrs
  7. 11-13 yrs

How kids' bike sizes work

Kids' bikes are named by wheel diameter, not frame size. A 16 inch bike has 16 inch wheels. Prevelo wheels run from 12 inches on a first balance bike up to 26 inches for older kids, with 14, 16, 20 and 24 inch sizes in between.

But wheel size alone does not tell you how a bike fits. Two bikes with the same wheel can seat a rider at different heights. The Alpha Three and the Zulu Three both roll on 20 inch wheels, yet the Alpha Three drops its seat as low as 21.2 in while the Zulu Three starts at 21.7 in. The Alpha sits lower for streets and paths; the Zulu sits a touch taller for trails. That is why we size by inseam and saddle height, not by wheel size alone.

Learner Fit and Pedaler Fit

The same child can ride two different seat heights depending on where they are in learning.

Learner Fit

The saddle is low enough to sit with both feet flat on the floor. Flat feet let a new rider start, stop and catch themselves without fear, so this is the fit we recommend while a child is still learning to pedal. In the Bike Sizer above, choose Balance bike or Learning to ride for this fit.

Child seated on a bike with both heels flat on the ground
Learner Fit: both feet flat

Pedaler Fit

Once a child pedals, steers and brakes on their own, the saddle can come up so only the toes touch down. A taller seat straightens the leg on each stroke, which is more efficient and comfortable on longer rides. In the Bike Sizer above, choose Knows how to ride for this fit.

Child seated on a bike on tiptoes, toes touching the ground
Pedaler Fit: up on tiptoes

A bike with a wide saddle-height range covers both: start at Learner Fit, then raise the seat toward Pedaler Fit as confidence grows.

From balance bike to first pedal bike

Most kids start on a balance bike with no pedals, often between 18 months and 3 years, as soon as they walk comfortably. A balance bike should fit at Learner Fit: upright, with both feet flat on the ground so they can push, glide and stop with their feet. The 12 inch Alpha Zero is built for exactly this.

When your child can glide with their feet up and steer under control, they are ready for a first pedal bike, usually a 14 or 16 inch wheel. Keep the same Learner Fit, both feet flat, so learning to pedal feels safe. The 14 inch Alpha One and Zulu One are common first pedal bikes.

There is no fixed age for the switch. Balance and confidence matter more than birthdays, so use inseam and the feet-flat test rather than a number.

Which Prevelo bike is right for your child?

Use your child's inseam (inner-leg measurement) as the main sizing guide, with age as a rough starting point. Then choose a series by where they ride: Alpha for streets and paved paths, Zulu for trails and mountain biking, and Bravo for pump tracks and dirt jumps. When a rider is between sizes, the smaller wheel is easier to handle and the larger gives more room to grow. Each model links to its full specs.

Alpha Series

Best forStreets, paved paths and light trailsRider levelBeginner to advanced riders
Model Wheel size Rider age Recommended inseam Recommended height Min. saddle height Weight *Price
Alpha Zero 12 inches ~ 1½ + 12½ to 16½ inches 33 to 43 inches 10.9 in / 277 mm 6.8 lbs$209
Alpha One 14 inches ~ 3 to 5 14 to 17½ inches 35 to 44.5 inches 14.75 in / 375 mm 11.3 lbs$449
Alpha Two 16 inches ~ 4 to 6 15½ to 22 inches 38 to 44.5 inches 16.9 in / 430 mm 12.1 lbs$459
Alpha Three 20 inches ~ 5 to 9 19 to 23 inches 42.5 to 52.5 inches 21.2 in / 540mm 16.9 lbs$679
Alpha Four 24 inches ~ 7 to 11 23 to 28 inches 49.5 to 59.5 inches 26.1 in / 665mm 19.2 lbs$719
Alpha Five 26 inches ~ 9 to 13 25 to 30 inches 53.5 to 64.5 inches 28 in / 712mm 21.5 lbs$779
Shop Alpha Series →

Zulu Series

Best forTrails and mountain bikingRider levelBeginner to advanced riders
Model Wheel size Rider age Recommended inseam Recommended height Min. saddle height Weight *Price
Zulu One 14 inches ~ 3 to 5 14 to 17 inches 36.5 to 43 inches 15.5 in / 395 mm 13.5 lbs$599
Zulu Two 16 inches ~ 4 to 6 16 to 22 inches 39.5 to 54.5 inches 17.7 in / 450 mm 15.1 to 15.8 lbs$649
Zulu Three 20 inches ~ 5½ to 9 20 to 26 inches 45 to 58 inches 21.7 in / 550 mm 20.5 lbs$1,149
Zulu Four 24 inches ~ 8 to 11 23 to 29 inches 48.5 to 60.5 inches 24.8 in / 630 mm 22 lbs$1,299
Zulu Five 26 inches ~ 9 to 13 26.5 to 31 inches 54 to 66 inches 27.6 in / 700mm 23.3 lbs$1,399
Shop Zulu Series →

Bravo Series

Best forPump tracks and dirt jumpsRider levelConfident to advanced riders
Model Wheel size Rider age Recommended inseam Recommended height Min. saddle height Weight *Price
Bravo Two 16 inches ~ 4½ to 7 16 inches and up 40 inches and up 17.5 in / 444mm 16.8 lbs$999
Bravo Three 20 inches ~ 6 to 10 20.5 inches and up 45 inches and up 21.75 in / 552mm 19.8 lbs$1,199
Bravo Four 24 inches ~ 8 to 13 24 inches and up 51 inches and up 25 in / 635 mm 21.5 lbs$1,299
Shop Bravo Series →

* without pedals

Have more questions about sizing, fit, and setup? See our Knowledge Base or contact us.

Common sizing questions

How do I measure my child's inseam?

Have your child stand against a wall in socks, feet a few inches apart. Slide a hardcover book up between their legs until the spine is snug, like a bike seat, and hold it level against the wall. Measure from the top of the spine straight down to the floor. That distance, in inches, is the inseam, and it is the single most useful number for sizing a kids' bike.

What if my child is between sizes?

When an inseam falls between two models, think about how your child rides. The smaller wheel is lighter and easier to control, which suits a newer or more cautious rider. The larger wheel gives more room to grow, which suits a confident one. If you are unsure, size down: a bike that is a touch small is far easier to learn on than one that is too big.

What is the difference between Learner Fit and Pedaler Fit?

Learner Fit sets the saddle low enough to sit with both feet flat on the ground, which gives a new rider the confidence to start and stop. Pedaler Fit raises the saddle so only the toes touch down, which straightens the leg and pedals more efficiently once a child rides on their own. In the Bike Sizer above, Learning to ride gives a Learner Fit and Knows how to ride gives a Pedaler Fit.

Can I size by height instead of inseam?

Yes. Inseam is the most reliable measurement, but if you only have your child's height you can size by that instead. The Bike Sizer above and the tables on this page both work from height as well as inseam. Keep in mind that two children of the same height can have different leg lengths, so confirm with the inseam when you can.

How long will a size last?

It depends on how quickly your child grows, but most riders stay on a size for roughly one to two years. Every Prevelo has a wide saddle-height range, so you can start the seat low while they build confidence and raise it as they grow. When the saddle is near its highest point and their knees come up high as they pedal, it is time to size up.

Should I size down for Bravo or dirt jumping?

Often, yes. On pump tracks and dirt jumps, many riders prefer a slightly smaller, more maneuverable bike, so it is common to pick a smaller wheel size in the Bravo Series than for everyday riding. If your child rides both styles, size the everyday bike to their inseam first, then consider sizing down for a dedicated Bravo.

Looking for help by age? See our Knowledge Base.