I'm running 26x1.25" Panaracer UrbanMax tires on my bike and am having serious problems with repeated pinch flats. These occur when I hit big bumps at speed. I'm not getting any puncture flats (yet). Although I like the faster ride and reduced rolling resistance of these tires, I've been getting repeated pinch flats using the 1.1-1.4" tubes. The rims are Performance Loco brand and are fairly wide for such skinny tires. I can actually feel the wheel "bottoming out" when I hit a bump at speed and this is when the pinch flats happen. The tubes that correspond to this tire size are really thin and fragile. What is the downside to using a 1.5-2.0" tube with this tire as long as I'm able to get it in the tire without pinching it? It's also quite possible the tires are just too skinny for the wide rims and this will keep happening. Does any one have advice on tire/rim compatibility and how to avoid pinch flats in general, besides the obvious "don't hit bumps" advice?