who says it hurts knees? i ask because i'm getting sore knees lately. there are a few factors i'm thinking; i'm riding a lot this summer. my group rides further, higher and faster than ever before (new young riders in group and the 'enduro effect') i switched to 1 x about 6 months ago and previously climbed steeps on a 29er in 22x36. that is much lower than 30x42. and at 48 i ain't getting any younger….. i really like the oval in general but i'm going to go to 28 round (still harder than 22x36 according to bike calc) to see if my knees get happier.
I definitely haven't noticed any issues with my knees on oval or round chainrings.. I will say that when I went down to a 28t round chainring that my suspension feel was affected negatively… back to a 32 oval right now and everything feels better… just have to work a bit more on the climbs. Having said that I will switch back to the 28 round for certain events that require a boatload of climbing, but for daily use I will stick with the 32 oval.