The Primer 18” is the ideal choice for riders who’ve outgrown a 16” but aren’t quite ready for a 20" BMX bike.
The shorter chain stay, lighter wheels and size-specific, pro-style frame geometry makes it the go- to bike for serious BMXers in this size range. The Primer is packed with quality parts like Odyssey Springfield Brakes and a fully sealed cassette hub for reliability that you can count on every time.
Key Features
- 18" Pro-Style Geometry
- Sunday Freeze Front Load Stem
- 9t Cassette Hub
- Sunday Cornerstone Grips
- Odyssey Springfield Brakes
- FSA Headset
- KMC S1 Chain
Frame Geometry
Top Tube Length: 18.5"
Head Tube Angle: 74.5°
Seat Tube Angle: 71°
Chainstay Length: 11.7-12.00”
Bottom Bracket Height: 10.35"
Standover: 7.5"
Handlebar Geometry
Rise: 7.65"
Width: 25.5"
Backsweep: 12°
Upsweep: 1°
Choosing the right size BMX bike is crucial for comfort, control, and performance. This guide will help you understand the ideal tire size and top tube length based on age ranges to ensure a perfect fit for riders of all ages.
Age Ranges and Recommended BMX Bike Sizes
-
Ages 2-5 (12" Tire)
- Tire Size: 12 inches
- Top Tube Length: 12-13.5 inches
- Description: These bikes are designed for the youngest riders, offering stability and easy handling to help them learn the basics.
-
Ages 5-7 (14" Tire)
- Tire Size: 14 inches
- Top Tube Length: 14-15.5 inches
- Description: Slightly larger than the 12" bikes, these are ideal for children gaining confidence and control.
-
Ages 7-9 (16" Tire)
- Tire Size: 16 inches
- Top Tube Length: 16-17.5 inches
- Description: Suitable for young riders developing their skills and needing a bit more space for comfort.
-
Ages 9-12 (18" Tire)
- Tire Size: 18 inches
- Top Tube Length: 17-18.5 inches
- Description: Perfect for pre-teens who are serious about riding and need a bike that offers more stability and control.
-
Ages 12-14 (20" Tire)
- Tire Size: 20 inches
- Top Tube Length: 18-19.5 inches
- Description: This size is common among teenage riders and provides a good balance of control and agility.
-
Ages 14+ (20" Tire)
- Tire Size: 20 inches
- Top Tube Length: 20-21.5 inches
- Description: For older teens and adults, the 20" bike with a longer top tube offers enhanced performance for tricks and stunts.
BMX Bike Size Chart
| Age Range | Tire Size | Top Tube Length |
|---|---|---|
| 2-5 | 12 inches | 12-13.5 inches |
| 5-7 | 14 inches | 14-15.5 inches |
| 7-9 | 16 inches | 16-17.5 inches |
| 9-12 | 18 inches | 17-18.5 inches |
| 12-14 | 20 inches | 18-19.5 inches |
| 14+ | 20 inches | 20-21.5 inches |
Shipped Direct to Your Home
Our Platinum Pro Assembly fee of only $25 will be added at checkout. Your Sunday kids bike will be built, fine-tuned and expertly packaged by our certified team of bike techs. Your new bike comes 90% built, reassembly is quick and easy with our video guides. Your new bike ships within 3-5 business days.
Pick Up at Bicycle Warehouse
$25 Ready to Ride
Bikes comes 100% built and ready to ride. This fee includes professional assembly & setup, one basic Master Service and free warranty processing. Shipped bikes are not charged this fee.
At Bicycle Warehouse your satisfaction is our top priority. We understand the importance of your happiness with every purchase, which is why we proudly offer our 30 Day Love It Guarantee for your unused gear and 14 days on all bikes. Our exchange and returns process is quick and easy.
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