I have been doing more 20 - 30 mile rides and it has occurred to me that my pace is much slower then i would expect. my cadence is ( to the best i can count) at least 70. my gear set up is 2x6, 53, 40 and 28,24,21,18,17,14. I ride almost exclusively in the 40, 14 gear. in this gear with a cadence of 70 a pace of 16mph ( in florida aka no elevation) does not seem right. My bike is 30 years old and as far as i can tell all original except the seat and brake levers. Centurion Omega steel frame bike. I had it tuned a couple weeks ago and that helped a little. Thank you for any help you can give me.