I've have the Forte GT2/k (27 x 1 1/8) on my commuter. Over 1,000 miles through glass, rocks, etc. on my route and only flatted three times. I run 105 psi on straight sided steel rims without any issues as long as I make sure the tire is seated properly before going to full pressure. Run the same set up on my wife's grocery getter and no problems there either.