Have hunted in griz land. 4 guys on horse/mule scares them away. Single or two people on foot? Pray to God. You are gonna need 12 ga. slugs. Bear spray is for the dead.
Are you familiar with the story of Field Johnson? He was a favorite guide of Jack O’Connor. He was mauled by a grizzly...probably while armed with his .30-30, and as familiar with bears as anyone is likely ever to be. He had the presence of mind to play dead, but got mauled pretty badly. When he deemed it safe to move, he did, but the bear was still nearby, and gave him the once-over, again. The experience drove Johnson to insanity.
Never been around grizzly/brown bears-only black bears that are less aggressive and much smaller. I would not go into grizzly country unless I was on horseback, armed and with a party of at least three people. I certainly would not go there on an E bike. Bear spray is not designed for them...