What's the furthest you've run in those shorts?

Wear whatever works the furthest and add bodyglide/vaseline to wherever rubs.

Ranger panties/silkies

I used a pair of Salomon shorts and didn't have any issues. Vaseline will be your friend. I found that socks became the most important thing in my life for a while, find the best pair for you and put some Vaseline on your feet. Have spare pairs at each aid station. Good luck.

---

..........................................................................

For me, it would be either 2 in 1 running shorts with boxer style or traditional running (cutout brief liner) with light compression short (Nike Pro or UA) underneath. I rend to get it upper inner thigh. I have also found slightly longer 7 or even 9 inch work better to keep material or seam bunching between legs. If it is raining I will double done on body glide.

I've always found the tri short (pref minus the chamois) the most comfortable.

I have done 100km in regular running shorts a couple of times, but not by choice. There was some major lubing going down on those days.

Never run that far but the lululemon running shorts are super comfortable and no chaffing. I always scoffed at them for being more geared towards women but ended up trying them and have to say they are probably my go to short now.