1, 60 on a dead stock bike flatland siting upright? check the speedometer or you changed your sprockets throwing the reading off. Even drafting, down a very long hill gravity powered tucked or drafting means nothing. I tried coming down the LONG hwy 74 hill from the back side of Robbinsville and i did briefly see 67 but, again, thats gravity and was messing with my buddy on his TU250..
2, its different it a lot of ways to the super cub, most notably the ecm is different. we have one of each here in the garage, the sc is my wifes, the trail is mine. Yes, the sc is faster than the ct stock to stock. Have had both ecms in my hand to compare them, and the 21s-22s wont interchange.
dmonkey is right, real world vs dyno theoretical are 2 completely different things. my 4'10" wife, who is tiny and has a very heavy throttle (and gas pedal) tendencies has never seen over (legit) 62 on her super cub. same with another friend of mine who has one, he can hit a legit 60-61 on a stock supercub. since they basically have a 1st gen grom ecm tune, this is on par as they would hit a legit max 62-64 tucked, stock and flat, have one of those as well. (but not stock anymore)
changing sprockets will affect how the speedometer reads, its driven off the output shaft of the transmission. used to see guys put 13t on the front and go up 2 on the back and claim their stock ass groms would go 80 back in 2014-2015 and die on that hill trying to defend that claim. Um, no.
and before somebody raises the elevation q, we are at 750 ish feet above sea level.
as an addendum, i know, for a fact, some of the very early non us spec bikes did run the earlier ecms. so that may play into it as well seeing higher speeds.
