i made some full length(no sections) ones a few week ago and instead of a rubber tip, I found some twigs from the oak tree in my yard that fit in the tips. epoxied them in, wrapped the tips with thread and epoxied over that (to hopefully fight splitting). drilled a hole in my oak dowel filled ends and epoxied a nail in there to create a metal tip. i'll take pictures later. so far i have only gone on a day hike with them, but they show no signs of wear.
i feel like the rubber stopper tip could potentialy fall of and leave the hollow bamboo end open for quick wear and splitting.
also try handlebar wrap instead of bmx style grips. its lighter, softer, and will fit any diameter/regular shaped bamboo.