Received the bike about a month ago. My first ebike. Have started riding it more as I get a sense of how long the battery will last. Riding is about 60/40 Roads vs bike path/trails. Got a slow leaking flat today. Tires are easy to remove off rim. However noticed the tires are very thin. Like shoebox thin. didn't see any tire punctures from the inside or outside of the tire. I actually like these tires, but cant find them anywhere else. So I am not making lots of tire repairs was considering trying out thicker tubes. Any suggestions on a suitable tube size . The Wheel is 26in and the current tire 26x 4.9 xxl Thanks.