[jvriezen]

'Bumper' is not even a glossary item and as such appears to have no special distinction as compared to other attachments or robots components/assemblies/mechanisms. In fact, there is no definition of where the boundary between a bumper and a non-bumper element is. If I want to call my steel bar located in the center of my robot a bumper, there is no rule that says I can't do so, and doing so has no impact on any aspect of the rules, as near as I can tell. Heck, I can claim my RoboRio is doing double duty as my bumper.

Edit: Having said all that, there is much practical benefit to not having teams remove and attach bumpers for every match. We've seen how that works in the past for many teams, but I don't think the rules speak to the issue.