end cap
I have the rusted bar ends. Pulled my caps off with pliers since they were falling apart anyway. Installed new ones and put some vasoline to stop the rust. No good. Took four corks from wine bottles. Pounded them in and used a magic marker to colour them black. Works for me.
RR
I realize this is an old post - but maybe useful for others. I used the super slider brand black rubber chair tips 1" and they fit easily and are snug on my yakima roundbars. IMO these are better than than yakima roundbar endcaps.
Be sure to select the 1" (not 7/8") 1" chair tips @ Walmart
I am using these: https://www.amazon.com/dp/B07N55ZXYV/ref=cm_sw_r_cp_apa_fabc_12T1Y36RCG6DXJANK12K?_encoding=UTF8&psc=1
I needed something easily removable as I switch between two crossbar lengths and these fit the bill perfectly