8-14years should be looking at an 65cc 2 stroke, 85cc 2Stroke or 150cc 4Stroke. However, those who are slightly taller from 13years can ride a 125cc 2Stroke or 250cc 4Stroke. Those aged 16years+ can ride anything upwards of 125cc 2stroke – this is your own personal preference.
This based on the engine make up. A 2Stroke machine require oil being added to the fuel and produces its capacity output once every revolution of the engine. A 4Stroke machine uses straight fuel and has oil in the engine. As its name suggests, the machine produces its power output every other revolution of the engine. Therefore usually the engines double the capacity of a 2Stroke are considered to have similar horsepower output and are grouped together, known as MX1, MX2 classes, see below.
MX1 is known as the big bikes and are usually 250cc 2Strokes and 450cc 4 strokes, but realistically MX1 is anything above 145cc 2Stroke and 251cc 4stroke. MX2 is the smaller adult bike capacity class, usually 125cc 2strokes or 144cc 2strokes, and 250cc 4Strokes. MX2 is known is America as the ‘lites’ class. The kids class is known as the Inters or Inter Juniors.
Motocross events allow riders from 9years and up. See below for which class you can enter.
Inter Juniors Class and Age Capacities:
|Age||Grade||Engine Capacity||Only Wheel size / Spec|
|8 + Years||Inter Junior||Max 65cc 2 stroke||12 inch rear, 14 inch front|
|9 + Years||Inter Junior||Max SW85cc 2 stroke or SW150cc 4 stroke||14 inch rear, 17 inch front|
|11 + Years||
|Max 85cc 2 stroke or 150cc 4 stroke||16 inch rear, 19 inch front|
Junior/Senior/Expert Class and Age Capacities:
|13 + Years MX2||(Junior/Senior/Expert)||Max 145cc 2 stroke or 250cc 4 stroke||-|
|15 + Years MX1||(Junior/Senior/Expert)||Max 250cc 2 stroke||-|
|15 + Years MX1||(Senior/Expert)||Max 450cc 4 Stroke||-|
|17 + Years MX1||(Junior/Senior/Expert)||Min 146cc 2 stroke or 251cc 4 stroke||-|
Age limits in this note applies to machine capacities NOT classes.
The AMCA prides itself on having ability racing classes, which we name Juniors, Seniors, and Experts. There is also a specialist kids class which is called the Inter Juniors. This is specifically for kids aged 8-14 on 85cc 2stroke/150cc 4stroke machines. The juniors is known as the novice ability class. When a rider starts winning races, they gain upgrading points. When a rider gains enough points, they are upgraded by local officials to the Seniors (the medium ability class). The upgrading system occurs again in this class up to Expert stature which as its name suggests is for the faster riders. Once in this class, a rider can enter qualifiers for national championships. If you haven’t raced before, you are best starting in the Juniors. Or if you previously made Expert grade and have a few years off, a rider can opt to go down a class. Of course, if a rider is deemed to be in an inappropriate class, they will of course be moved into a more appropriate class on the day of an event.
The AMCA office usually issues the next available race number in your class – every number in a class in a geographical area is unique to avoid duplication. However, if you would like the office to look for a specific number in your class, then please feel free to ask – as long as no other rider has it in your area and class, we can give it to you. Remember, your race number will change if you change classes, unless it is available. The top 30 numbers in the Experts are reserved exclusively for MX1/MX2 Championship riders.