# Wheels

Most wheels used in FIRST Robotics Competition can be divided into four categories; Standard, Omni, Mecanum, and Compliant. One element to consider when choosing a wheel is the bore size, and if you will need any additional hubs to convert your wheel to the needed input or output. 

Most sizes of ION wheels feature a MAXSpline bore that can fit standard 1.125in OD bearings or easily be adapted to other bores using MAXHubs. Smaller wheels feature 1/2in hex bore. Larger sizes of ION Traction, Grip, and Omni Wheels have spokes with a bolt circle of #10 clearance holes patterned outward at 1/2in pitch. They also have a 3/8in-wide nut groove that eliminates the need for a wrench when utilizing the holes on the spokes.

## Wheel Basics 

REV Robotics offers three types of ION wheels: [ION Traction](https://docs.revrobotics.com/ion-build/motion/wheels/traction), [ION Omni](https://docs.revrobotics.com/ion-build/motion/wheels/omni) and [ION Compliant](https://docs.revrobotics.com/ion-build/motion/wheels/compliant). There are two types of ION Traction wheels available: the standard [ION Traction Wheel](https://www.revrobotics.com/ION-Traction-Wheels/) and the [ION Grip Wheel](https://www.revrobotics.com/ION-Grip-Wheels/).  The main focus of the traction wheels is to pull a robot (or create traction) in a forward/backwards motion. 

![](https://2800450911-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F4vnkeyE3Rv32OmveFas2%2Fuploads%2F6p9PW6GM6A5oN4t1FrAh%2Fcut%20away%20wheel.png?alt=media\&token=ae2de399-8351-4fab-b5c0-dd331614db73)

{% hint style="info" %}
[ION Grip](https://www.revrobotics.com/ION-Grip-Wheels/) / [ION Traction](https://www.revrobotics.com/ION-Traction-Wheels/) / [ION Compliant ](https://www.revrobotics.com/ION-Compliant-Wheels/)wheels can easily be mounted flush when a build needs to gain load capacity or to increase traction as the cross section image above illustrates
{% endhint %}