Does 54" include bumpers?

[Basel A]

R5: For the purposes of determining compliance with the weight and volume limitations, the items listed below are not included in the weight assessment:
A. the ROBOT battery and its associated half of the Anderson cable quick connect/disconnect pair (including no more than 12 in. of cable per leg, the associated cable lugs, connecting bolts, and insulation) and
B. BUMPERS (including BUMPER covers, if appropriate).

Emphasis mine. 54" diameter cylinder isn't exactly volume, but I would interpret the rule as saying that bumpers don't count toward the 54". This is a question for the Q&A, though.