Official Q&A: VRC 2020-2021: Change Up Usage Guidelines

Dyeing Rubber

1 month ago


There has been debate in the community about the legality of dyeing rubber.


Robots are built from the VEX V5 or Cortex system. Robots may be built ONLY using official VEX V5 and Cortex components, unless otherwise specifically noted within these rules. Teams are responsible for providing documentation proving a part’s legality in the event of a question. Examples of documentation include receipts, part numbers, official VEX websites, or other printed documentation.


Any parts which are identical to legal VEX parts are permitted. For the purposes of this rule, products which are identical in all ways except for color are permissible. It is up to inspectors to determine whether a component is “identical” to an official VEX component.


Decorations are allowed. Teams may add non-functional decorations, provided that they do not affect Robot performance in any significant way or affect the outcome of the Match. These decorations must be in the spirit of the competition. Inspectors will have final say in what is considered “non-functional”. Unless otherwise specified below, non-functional decorations are governed by all standard Robot rules.

2013 Q&A

Recently it has come to my attention that there is a way to modify the opaque green rubber of the dual roller omni wheels and high traction tires through the process of submerging the wheel in a pot of boiling water.

Dyeing Rubber wikiHow (Method 1) Step 2

Fill a pot with water and heat it on a low to medium stove setting. The water should be hot, but not boiling—close to, but less than 212 °F (100 °C) is ideal.

Step 4

Place the object in the bowl and leave it to soak. Keep it in the pan for up to 2 hours, depending on how strong or bright you want the new color to be.

The 2013 Q&A states that “hyper-hydrating” rubber is illegal for use in VRC because it is ‘not safe’. Hyper-hydrating rubber only requires boiling water while teams are allowed to use more dangerous power tools like bandsaws and dremels.

The community would like an official test done by the GDC to see how “hyper-hydrating” 3.25, 4” and the different durometers of flex wheels modifies their properties.

  1. Does “hyper-hydration” change the properties of rubber enough to affect the outcome of a match (and to break R13)?

a) If the answer to the bolded question is no, is boiling wheels with the intent of “hyper-hydrating” with no intent of modifying color legal?

b) If the answer to the bolded question is yes, is there a specified amount of time and water temperature that would be considered “hyper-hydration”? There have been teams who get a nice rubber color with water at 190F and a higher dye concentration.

  1. Is there a preferred way teams should dye their omni-wheels and flex wheels that doesn’t cause it's properties to be changed enough to break any rules?

Thank you for your time

Answered by Game Design Committee

First, thank you for the well-organized question and for quoting the relevant rules from the Game Manual.

is boiling wheels with the intent of “hyper-hydrating” with no intent of modifying color legal?