I have been experimenting with tire sizes to determine what is the best tire to use for pavement and sidewalk riding while still have as much speed and comfort as possible. I understand that there may be trade offs between tire size, speed, and comfort.
The best combination I seem to have found is a set of 700 by 40c tires that have a max psi of 50. However, those are on a gravel bike that I have. I have a fixie that I have been working on and want to use as more of a commuter bike. I put some old 700 by 35c tires that I had laying around on it.
The issue is that one of the tires seems to always lose air even though there did not seem to be any holes in the tube (that I can tell). I removed the tube and pumped it and it seemed to keep the air in for days, however, if I put the tube in the tire and inflate it, even without riding it loses air within half a day. So I replaced the tube and that worked fine. But then while riding last night, I hit a slightly raised section of pavement and got a flat.
Upon inspecting the tube there is a small slit along the inside area. Is this what a pinch flat is? The tire was inflated to 60 and felt fine even though it has a max psi of 85. I also checked to make sure that it is not an issue with a protruding spoke or anything like that and it does not seem to be. All the spokes seem to be appropriately recessed in their groves. I want to know how I can avoid this, because I will often be riding over this type of terrain. Would having the tire be inflated to the max recommended have avoided this? Do I need different types of tire? Do my gravel bike tires handle this type of terrain better just because they are bigger or because they have a low psi rating?