Hi. I'm a novice when it comes to my bike. I just got new Nimbus EX tires for my Mtn Bike for when I'm city riding. I took off the Panaracer Fire XC Pros I had on them, put the new Nimbus' on, inflated the tubes, but I now have a "flat" part on each tire. The tires are round except for one part on both of them, where they're flatter by about a 1/2 inch. Can't find any rhyme or reason for it, the flat part is in a different location for each tire in relation to the tube valve, I measured the rims (Mavic Crossroc UST Tubeless) to make sure they were round, theyre fine. Anyone have any idea whats wrong? Are the tubes or tires seated wrong somehow? Is it possible the tires are just defective?