ByK E-450x3i Review

The lightweight ByK E450x3i‘s larger tire size and low center-of-gravity design allow kids to ride easier, sooner, and faster. The internally geared hub simplifies shifting, but assembly is a challenge. Read the full review below!

boy riding the ByK E-450x3i bike

ByK E-450x3i Review

RATING: Recommended


BEST FOR: Riders sticking to pavement who want geared options on a bike, but prefer the simplicity of just three gears.

SEAT HEIGHT: 23.3″ – 28.7″

WEIGHT: 20.8 lb.

GEARS: 3-speed with internally-geared Shimano Nexus Hub
BRAKE: Coaster brake with Front Hand Brake


  • Easy to use 3-speed internally-geared hub
  • Larger-diameter, thinner tires result in a comfortable, fast ride on pavement
  • Lightweight for its price range


  • Challenging to assemble, does not come with tools or instructions
  • Quality of components could use improvement
  • Poor quality caliper front brake

ByK E450x3i Review – Results of our Test Rides

Lightweight and speedy, ByK’s E-450x3i is a notable option for neighborhood bike riders, ages 5 to 9, who need the flexibility of gears.  With thin tires that easily roll across the pavement and an easy-to-use, 3-speed, internally geared hub, the E-450x3i packs a lot of fun into a mid-range price point.

6 and 7-Year-Olds on the ByK E-450x3i

Young boys riding the ByK E-450x3i kid's bike in blue

Size and Weight

The ByK E-450x3i bike has slightly larger wheels than traditional 20″ bikes, but is similar in overall size to 20 inch bikes with larger frames.  Our 6-year-old tester in size 5 clothes and our 7-year-old tester in size 6 clothes both fit great on the bike, but we wouldn’t recommend the 450 for a child in size 4T clothes.  The handlebars on the ByK were a good height for our 6-year-old, but would likely be too high for a smaller child.  The smaller E-350x3i, which also has an internally-geared hub, is a better choice for kids in 4T clothes. You can refer to our Bike Size Guide for Kids to find the right size Byk for your child.

Weighing in at 20.8 lb., the ByK is on the lighter end for geared 20″ bikes and wasn’t an issue for our riders.  The bike easily rode up and down ramps and up paved hills without any concern.

Internally Geared Hub

ByK E-450x3i’s 3-speed internal hub is the bike’s standout feature and main selling point.  We love internally-geared bikes for young riders, especially the Shimano Nexus hub which the 450x3i features.  Internally-geared hubs allow bikes to have gears, but without a derailleur.  Derailleurs are notoriously finicky, need regular maintenance, and sit really low to the ground on kids’ bikes, which causes them to get damaged easily.

Additional Clearance with Internally-Geared Hubs

Comparison showing little clearance with a traditional derailleur on a kid's bike, vs more clearance on a bike with an internally geared hub on ByK E450x3i


Shifting an internally-geared hub is very easy and straightforward.  Kids simply twist the inner portion of the right handlebar grip either forward or backward.  With only three gears to choose from, we found our younger testers prefer the simplicity of 3 gears versus the complexity of 6 or 7 gears.  As an added bonus, unlike traditional shifting systems on bikes, kids can shift an internally-geared hub at any time, even while the bike is at rest, without worrying about causing the derailleur to get out of alignment.

The shifters on the ByK E-450x3i have a viewing window which visually shows a 1, 2 or 3 so that kids can easily tell which gear they are in.  The window on the shifter, unfortunately, did crack during a crash but the damage was only on the surface and did not affect the shifter’s performance.

Additionally, our testers found the window view shifter hard to read due to the glare from the sun.  As a result, they preferred a standard view shifter, like that found on the Priority.

Differences in Gearing Indicators on Shifters

1) Window view shifter on ByK hard to read with glare from the sun. 2) Standard view shifter is easier to read on the Priority bike. 3) Window of shifter on ByK E-450x3i cracked during a crash.


The ByK comes with dual-hand brakes as well as a coaster brake.  While the coaster brake would normally be duplicative, we found it to be necessary as the handbrakes on the ByK were challenging to use for our 6-year-old tester, who is average in size for his age.  The main issue is that the placement of the shifter causes the brake lever to be set further in on the handlebars.

To reach the brakes, the child has to reach at an angle, which was a stretch for small hands.  The brake lever can be adjusted closer to the handlebars, but it still required our testers to loosen their grip on the handlebars to reach the levers.  Shifting, however, was not a problem for them.

6-year-old Braking and Shifter the ByK E-450

Shifter and handbrake on ByK E-450x3i showing 1) Regular grip, 2) Reaching for the brake is a bit of a stretch, 3) The brake engaged, 4) Child's twisting the shifter

The front brake on the bike was also problematic because it’s a caliper brake versus a v-brake.  Caliper brakes are not nearly as effective as v-brakes and rarely stay properly aligned.  The main problem is that caliper brakes only mount to the top of the fork, not to both sides, so they easily shift side to side and get out of place.

V-brakes (like the rear brake on the ByK) mount on both sides of the fork and are much less prone to shifting out of place and are much more reliable than caliper brakes.  Due to the special mounts required on a fork to mount a v-brake, caliper brakes are often used to save on costs.

Caliper Brakes vs. V-Brakes

Front caliper brake on ByK E-450x3i is attached only at the top of the fork, which rarely stays properly aligned. Front V-Pull brake On Priority Start attaches to both sides of the fork, and is rarely out of alignment. The rear v-pull brake on the ByK E-450x3i is higher quality than its front caliper brake.

Other Features


The ByK E-450x3i is also unique in that it comes with smooth, narrow tires as compared to traditional wider, knobbier all-terrain tires.  The smooth tires provide a smooth and fast ride that our testers all loved.  As expected, the tires did not perform as well on dirt, but certainly excelled on the pavement.


Due to its threaded headset, the height of the handlebars on the ByK can be adjusted.  Most higher-end bikes have threadless headsets that do not allow the handlebar height to be adjusted.  Threadless headsets are generally preferred as they provide a tighter hold on the handlebars which keeps them properly aligned with the front wheel.  They are therefore essential for any type of higher-level riding, from BMX to road and mountain biking, and are found on all higher-end bikes.

Considering the ByK 450 is designed for the average, non-aggressive child rider (who is less likely to put more strain on the bike’s headset), its threaded headset works just fine and has the added benefit of height-adjustable handlebars for a more precise fit for your child.

Gearing Mechanism

As an internally-geared bike, the ByK E-450x3i does not have a derailleur, but does have a portion of the gearing mechanism that sticks out past the rear axle.  Unlike the E-350x3i, the 450 does not have a protective cage around the exposed gearing system (called the Bell crank unit).  Through our tests, however, we didn’t have any problems with the bell crank unit, but we would still recommend teaching your child to either use the kickstand or have them set their bike down on the left, versus right side.

ByK’s Tires, Headset, and Bell Crank

1) ByK's thin road tires are thinner and smoother than Priority's wider, all-terrain tires, 2) The ByK's headset allows handlebars to raise up to 1", 3) Part of the gear mechanism on the ByK E-450x3i is exposed, but durable


With a garage full of kids’ bikes, we’re pretty confident in our bike assembly skills, but the ByK was a bit challenging for us to assemble.  Not only did the bike come without tools or any real instructions, but it also appeared to be shipped directly from the factory without final tuning or tightening of bolts.  This is common with other low and mid-range brands such as Schwinn or Diamondback, but this is first-time tools for assembly as well as proper instructions have not been included. As a result, if you’re not familiar with assembling a bike (including adjusting brakes), or if you don’t have tools, we recommend having the bike assembled at a bike shop.  These images below are of the E-350x3i, but the 450 requires the same tools and assembly process.

Various Tools are Needed (and not included) to Assemble the ByK

Headset, wheel axle, and brake require special tools (not included) for assembly of ByK E-450x3i.

For those ready to tackle assembly, here’s the list of required tools as listed in the owner’s manual: 5-10 cm and 32 cm adjustable wrenches, 15 mm flathead screwdriver, 15 mm Phillips screwdriver, 2-8 mm Allen wrench set, set of open end spanners 7-17 mm, set of tire levers, chain link remover, wire cutters, and a torque wrench.


There are several 20 inch bikes on the market with 3-speed internally geared hubs, but the E-450x3i is the only one to come standard with narrower street tires.  Narrow tires, as well as the ByK’s coaster brake, aren’t ideal for all-terrain riders but can be a good match for most neighborhood riders.

ByK 450x3i Comparisons

Model (link to review) ByK E-450x3i ByK E-450 Priority Start 20 Cleary Owl 3-Speed
Price $349 $299 $379 $485
Gearing 3-speed Internal Single 3-speed Internal 3-speed Internal
Seat Height 23.2" - 28.7" 23.2" - 28.7" 22" – 28.5" 21" – 26.4"
Weight 20.8 lb. 18.6 lb. 19.5 lb. 19.1 lb.
Front Brake Caliper Caliper V-brake V-brake
Rear Brake V-brake, coaster V-brake, coaster V-brake, no coaster V-brake, no coaster

ByK E-450x3i: Best for riders who need a coaster brake as well as pavement-only riders who would benefit from a thinner, smoother tire.

ByK E-450: The single-speed version of the 450x3i, best for pavement riders who don’t need gears.

Priority Start 20: With a slightly smaller frame than the ByK, the Priority is better suited for beginning to average riders. It’s also the easiest to assemble of the lot and comes with higher-quality front and rear v-pull brakes.

Cleary Owl: Built for all-terrain riders, the Owl is the most aggressive of the lot and is best for adventurous riders.

Bottom Line

The ByK E-450x3i provides a fun, fast, and smooth ride for ages 5 to 9.  While it’s a great option for those sticking mainly to the pavement, its difficult assembly requires experienced parents or a bike shop to assemble.

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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