Hi everyone … my team has a doubt regarding wheels allowed for FRC … these are 8" wheels (ummmm huge). I’m assuming there is a rule to do not use so big wheels, but Ii’m not sure seems not clear enough or cudn’t find the rule on materials. Could you please clarify us?
Best.
Do you see a rule in the Game Manual that says 8" wheels are forbidden?
For FRC, those are small compared to some I’ve seen in the past…
There is no particular rule saying that teams cannot use wheels over a certain size.
The only constraints would be the frame perimeter and height limit. If you wanted to, you could use 48” wheels (anything bigger would exceed the height limit and therefore be illegal per this year’s rules)
Biggest wheel I’ve ever seen used: 2481’s 2021 robot.
Bicycle wheel shooter, kinda the coolest shooting mechanism ever.
I’ve seen teams use like 12" bicycle wheels before (legal, but don’t do this, it was bad), you should be fine
875 had a pair of bicycle wheels for drive and casters in 2004 I think.
That robot still exists somewhere.
There was certainly no such rule in 2020 
We stopped using 8" metal mecanum because of the weight, but they are very resistant and reliable during the match and easy to change if they break.
2016 teams were using 8 inch pneumatic wheels or 8 inch plaction wheels to get over the rough terrain and the high bar. No rules on wheel sizes. Just geometry of how it will fit in the robot, and how the bumpers will fit in the bumper zone as you change wheel diameters.
Edit: I could’ve sworn we had 10 inch wheels but I can only find up to 8 inch plaction from Andymark. Maybe that size was a special thing or im misremembering. Still big though.
You could just squeeze in 1 49in wheel if you angle it with a 49in x 11in chassis
Also, if you’re mounting these on an AM14U chassis do pay attention to where your bumpers sit. Your frame will now be an inch higher than it was on 6" wheels.
On the mechanical side, FRC is a “you can use anything” competition. Everything that is not dangerous and doesn’t otherwise violate a rule is allowed.
The area where you have to be careful about rules is electronics, control, and power. There the manual mandates a control system and a list of allowed actuators. I would suggest reading sections 8 and 9 of the manual carefully.
But there are reasons not to use those wheels besides them being illegal, namely that they are mecanums, and mecanum drives are generally not recommended.
I saw a team use like 10 or 12 inch mecanum wheels for their chassis before
Andymark has a 10 inch set as well.
You can use those, but be aware of the bumper rules.
Also, be aware of the weight limit – we used large mecanum wheels in Stronghold. IIRC, they’re something like 3.5 lbs each, so you have 14 lbs just in your wheels, without considering drive train.
And, you’re going to have to think about gearing: you’re only allowed ONE drive motor per wheel, and those wheels are going to take a bit more torque than smaller wheels to get moving.
We used (and destroyed a bunch of) 10" mecanum wheels in 2016. Not a great decision but we did ok; only one of the defenses (the ‘rock wall’, IIRC) got the better of our bot. But the 1" cable protector tended to bend the wheels all to heck. And they weighed a ton.
26" wheelchair wheel. Don’t do it, not worth it.
If you go back in time, there were quite a few robots with big wheels
Most any experienced FRCer will tell you that these are legal, and many have, but that is not what’s important here. Section 1.7 of the game manual states:
The intent of this manual is that the text means exactly, and only, what it says. Please avoid interpreting the text based on assumptions about intent, implementation of past rules, or how a situation might be in “real life.” There are no hidden requirements or restrictions. If you’ve read everything, you know everything.
That means if you can’t find a rule telling what wheels you can or cannot use, you can use whatever wheels you want, or no wheels. Use word search, have everyone read the manual completely, every single page. As your team members learn the “evergreen” rules back to front they you won’t need to look stuff up as often, but every question of legality should checked with the manual, and only if there’s an ambiguous rule might you need check with the Q
and A or CD.
Good grief… Warn us of the carnage. That poor robot didn’t have a chance of getting back up. Like a turtle on its back. They didn’t give up though.
