mate calm down, no need to refer to people as wankers. this is the second time in a few hours that i have said this to someone. everyone is entitled to their own thoughts and opinions. dont forget this is a PUBLIC forum, ppl will choose weather they want to post and what content they post is up to them.
100kph is a little over the top for a 138cc. i have too been curious to know the speed but if your so keen on knowing, take it to a long back street. get your mate in his car and test it. will take all of 2 minutes and you will have an accurate idea of how fast YOUR bike goes with your body weight etc etc... all bikes are slightly different.
my brother, friend and myself all own gt's and mine is about 2kph faster than theirs although their exactly the same and we have roughly the same body mass.
if you want a speed reading go out, check it and just have some fun, and stop with all the "wanker" crap.
Cheers, Tony.