Product Description
The Sunday Primer 20" is built for riders stepping into full-size BMX who want a proper setup that’s ready to progress straight out of the box. Designed around Sunday’s proven pro-style geometry, it delivers a balanced ride that feels stable, responsive, and easy to control.
This version features 20", 20.5", 20.75" or 21" top tube options, making it ideal for mid-sized riders or anyone looking for a versatile, all-round setup. The geometry keeps things predictable and confidence-inspiring, while still offering enough responsiveness for learning tricks, riding park, or hitting the streets.
Built from hi-tensile steel, the Primer is tough and reliable, designed to handle regular riding and progression. It comes equipped with quality components throughout, including an Odyssey Springfield U-brake, sealed cassette hub, and wide 2.4" tyres for grip and comfort.
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BMX BIKE SIZE GUIDE
BMX bikes are measured in two ways: the size of the wheel (20” is the standard BMX wheel size), and the length of the frame which is gauged by the top tube measurement. We have also simplified for you into XS, Small, Medium, etc.Here is a guide to what size you should be looking for - note that there is some overlap in sizes, as personal preference also comes into the equation!
| Rider Height (in) | Rider Height (cm ) | Wheel Size (in) | Top Tube Length (in) |
|---|---|---|---|
| 2FT - 3FT | 60 - 90cm | 12" | 11.5" - 13" |
| 2'8" - 3'4" | 80 - 100 cm | 14" | 2.8" - 15" |
| 3FT - 3'8" | 90 - 110cm | 16" | 14.5" - 17" |
| 3'6" - 4'6" | 105 - 135cm | 18" | 17" - 18.5" |
| 4'6" - 5'1" (XS) |
135 - 155cm | 20" | 18" - 20" |
| 4'10" - 5'4" | 147 - 162cm | 20" | 20" - 20.25" (XS - S) |
| 5'2"- 5'8" | 157 - 173cm | 20" | 20" - 20.5" (S - M) |
| 5'6" - 6FT | 165 - 185cm | 20" | 20.25" - 21" (M - L) |
| 6FT + | 180cm + | 20" | 20.75" + (L - XL) |




