Tire Swap

The below question was asking if you can swap all four wheels and remove a center straffing wheel post check in. I believe this ruling is this way because of the removal of the center wheel. If a team simply wanted to go from 4 omni wheels to 2 omni wheels and 2 rubber but changed nothing else, would you believe this is acceptable?


I’d bring all wheels to inspection, let the inspector know the situation, and ask if they would like to inspect the robot in each configuration. Show the robot never exceeds 11x19x15. That way both versions are legal and passed and event staff has been notified.


yes i belive that it would work

it is what we did for our robot

Wouldn’t that create a new robot (and violate R2) since wheels are part of subsystem 1 (mobile robotic base)?

It is not uncommon at all for teams to tweak their designs throughout the span of a competition. The teams may then resubmit for inspection to make sure their creations still play within the rules.

Specifically, R1A and R1B allow for exactly these types of changes; R2 also calls out “it is expected that teams will make changes to their robot at the event”.

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I’ve seen teams swap wheels, I’ve also seen team extend the wheelbase during the event.

When in doubt, ask a referee for a size re-inspection. It takes a few seconds.

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Based on the QA, I tend to agree with this. The wheels are part of sub-system 1, and sub-system 1 can not change.

So, teams should not be swapping out wheels during a tournament.

You can always ask for a re-inspection. Takes seconds and isn’t a big deal.

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Not quite true, <R2> only prohibits a complete swap of subsystems 1 or 2:

(emphasis mine)

Absent any further guidance, I would rule that swapping only some of the wheels for omnis would be OK, since it wouldn’t be “swapping out an entire subsystem 1”.

But then again, I would have ruled that swapping out all the wheels was OK too, on the grounds that “subsystem 1” includes not just the wheels but also the structure and chassis that hold the “mobile robotic base” - so even if you swap out all the wheels that still wouldn’t be a complete swap of subsystem 1.

But then Q&A473 got answered ruling to the contrary (someone asked for clarification on this in Q&A554 today).

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