“Can we use rubber bands made of different materials” has been an open question in VRC for a long time, with Q&As in various previous seasons leading to different answers.
But in IQ, it’s always been clear that you could use rubber bands made from any material as long as they were the right size - see R8b from the Rise Above game manual:
and that rule had been present in various previous IQ game manuals.
But, that provision is missing from R8 in the Pitching In manual – now the only legal “non-VEX IQ components” are non-functional decorations and EDR ⅛" metal shafts. I suspect the motivation behind that change was to avoid the arms race of teams looking for the “best-performing” rubber bands for their catapults, potentially at a significant cost. Seems like a reasonable goal to me.
(sidenote - if you want to go down a rubber band-related technical rabbit hole, read up on high-performance rubber band-powered gliders, the comparisons between different batches of rubber get pretty crazy. This video is a fun watch if you’ve never seen them before.)
Now, a further complication – buying rubber bands from VEX can get expensive quickly, but you can buy the same rubber bands from other sources at a much lower cost. For example, the VEX “non-latex” #64 rubber bands (276-3990) are Alliance non-latex rubber bands. Buying the 10-packs from VEX, they run about $0.40 each, but if you buy a 1lb box from Amazon, you’ll get the same bands for about $0.03 each (and that’s more expensive than usual, the 1lb box is currently $10; last time I looked I think it was $5).
So - if you buy the same rubber bands from a different source, are they legal to use on your VIQC Pitching In robot? In previous VRC games, they answer would definitely be “yes” - there has been a long-standing rule in the VRC manuals that allows “any parts which are identical to legal VEX parts” to be used. (Actually as I was writing this I noticed that rule is missing from the new VRC manual – but that’s another topic, probably worth its own thread)
Anyway, in IQ we’ve never had that exception so we’re bound only by R7a:
But in this case the assertion that “official VEX IQ products are ONLY available from VEX Robotics” isn’t really true, since you can get the same part from other sources – not just an “identical” part for some definition of that word, but literally the same parts, just routing through different warehouses on the way from the factory to your robot.
I think “can we buy the same rubber bands from Amazon” is a good question for the Q&A when it opens.