I ride a touring bike with racks, fenders and panniers and ride with a group of 50 to 70 year olds like myself. Many of them ride 19 to 20 pound road bikes and after 20 or so miles I find that the faster ones start pulling away from me. I removed the racks, fenders and panniers and took off the touring tires and replaced them with 700 X 28's which is the narrowest tire I can put on my wide rims. I managed to lighten my bike by about 6 pounds. This added about 2.5 MPH to my average. I can't ride a road bike with drop bars due to a bad back so I have to use flatbars with bar ends. My rear wheel spacing is 135 and I understand that a road bike rear wheel is spaced 130. Is this correct? I have some 10 year old mountain bike (LX) hubs that I could have built up with narrow rims so I could use an even narrower tire. Would this help? I don't want to spend $2000 or more for a new bike. I am a big guy (195#) and wonder if a new wheelset with 20/24 spoke wheels would hold my weight. Or is a new bike in my future? Any other ideas? Thank you, Rich