hobbsc

i've got a set of kenda k-rads (26") and a rear v-brake on a 2019 wtp avenger. the tires are gum walled and i can see some diagonal straight lines in the tire wall that are lighter in color than the wall. are those an indication of failure? the tires seem fine when i pulled them off and inspected them. they've been on for probably a year and a half. tread is still terrific. trying to decide if they should be replaced. i mostly bomb hills and jump off silly stuff with this bike.

also the rear brake is getting a little beat up. does anyone have recommendations for a decent rear v-brake? when i look for bmx specific things, the box one/two/three stuff comes up a lot. i'd never heard of the brand before so i wasn't sure if it was any good. may just consider a mtb brand since that's what i know and i probably have something floating around in the parts bin.

thanks!