This Q&A is now read-only
Official Q&A: VEX U Robotics Competition 2025-2026: Push Back
2805: VUG4: O-Rings / Friction Belts
<VUR8b> “Teams may use commercially-available springs on their Robots. For the purposes of this rule, a “spring” is any device used for storing and releasing elastic potential energy. Examples include, but are not limited to: Springs made from elastic thread or rubber, such as surgical tubing, bungee cords, or stretchable braided rope.” <VUR4> “Fabricated Parts must be made from legal Raw Stock. To be considered Raw Stock, the material must be obtained in one of the following forms before undergoing the fabrication processes listed in <VUR3>: … Solid Rod, Hollow Rod / Tube” <VUR5> “The following material types are not considered Raw Stock, and are therefore not permitted: … Commercial Off-the-Shelf items that are intended to be used with minimal modification (ex. Wheels, Gears, Timing belts and pulleys)”
According to VUR8, surgical tubing is legal as a spring, but surgical tubing is also legal in any other use on the robot because its form is considered raw stock (solid rod or hollow rod / tube) according to VUR4.
The questions we have concern round belts or o-rings like this one (https://www.mcmaster.com/products/round-belts/round-belts-1~/flexible-round-belts/). There are many round belts made of polyurethane, neoprene, or other surgical tubing-like materials. The main difference is that it is a ring instead of a bar or rod (a bar or rod with the ends attached).
VUR5 mentions timing belts being illegal to use as stock (obvious exceptions for the VEX timing belts). However, round belts are not considered timing belts as they do not have teeth, but they are technically not rod like the surgical tubing that is legal according to VUR4.
- Is it legal to use round belts like the above example for belting on our robot, or would we have to use them as springs in order to use them?
- Is it legal to use preconnected round belts / rubbing as listed above, or would we have to use disconnected straight belts / tubing that must be welded or attached to make a circle later? (like this: https://www.mcmaster.com/products/round-belts/round-belts-1~/round-belting/)
Round belts do not fit into any of the allowable forms of Raw Stock available for use in the VEX U Robotics Competition, per VUR4.
Is it legal to use round belts like the above example for belting on our robot, or would we have to use them as springs in order to use them?
Round Belts are not surgical tubing, bungee cords, etc. They are obviously intended as commercial off the shelf items that are intended to be used with minimal modification. Round belts, like the ones linked from McMaster in the question, are not legal for use on VURC Robots.
Is it legal to use preconnected round belts / rubbing as listed above, or would we have to use disconnected straight belts / tubing that must be welded or attached to make a circle later?
See above. Pre-connected round belts would be used on the Robot with no modifications, as described, and would not be legal for use on VURC Robots.
If a Team is able to construct their own round-belting from legal Raw Stock, it's possible that this could be considered legal.