Riddle me this NSMB, after years of commuting puncture free, I seem to flat every week or two in the front. I'm running a cheap Rocky road bike with Schwalbe Marathon's. Tires are getting a bit long in the tooth (maybe 2 years of riding) but still seem to have a lot of life left.
I've checked the tubes, the rims and the tires and can't find anything causing the problem. They're flatting in different spots so I'm inclined to believe it isn't a problem with something sharp in the rim / tire. I've switched to different tubes a couple of times in case it was a manufacturer issue. I've re-taped the rim. I've switched the front / rear tires (in case it was a tire issue). Still seems to happen.
I am running pretty close to max PSI, around 100 to 105. Rear seems to be holding its air (after a week, it's still at 105, front is flat).
Thoughts or solutions?