Sliding on asphalt while wearing a textile jacket without armor will quickly wear/melt holes. Leather is a little tougher but eventually it will tear a hole if the abrasion is long enough. Some bike mag (Cycle World/Motorcyclist) did a short article about this a while back. I'd been riding with my Triumph Retro Paddock textile jacket and armor removed. After reading the article, I put the shoulder and elbow pads back in place.
