I weigh 245 #´s, Sr, Citizen, 2005 TW200 with 380 miles on it... no mods... for me... 58mph is all I get, I´m at 700 feet elevation. A 125# kid might make 65mph indicated, but the speedo is known to read about 3 or 4 mph faster than what my Garmin 76CMap reads, which is true speed. Keep in mind, my engine is still tight and not fully broken in yet, I might get more in time. I get about 85 mpg, not bad when gas is $3.30 a gallon.