I’ve taken helmets, ropes, harnesses, chalk bags (unidentified white powder) many times without issue.
I always put the rack in hold luggage though. My go to whenever I have been questioned (although only based on the size of my hand luggage, not the content, and typically at the gate) is to say I’ll not bother taking the flight then. This means they’d have to unload my checked bag from the hold & amazingly they seem to find space for my slightly larger hand luggage.
It does seem a little naughty but I think why not, the usual punters are allowed 8ft of duty free toblerone & other nonsense as additional carry on, plus since I keep myself lean I feel extra weight allowance should be afforded for my efforts
Post edited at 16:29