After about 1500 km's to try out cycling i went from this KS Cycling Velocity 2nd hand cheap fitness bike, to this Isaac Vitron Disc 105. And i should have done that
KS Cycling Fixie Fitness-Bike Single Speed 28'' Essence schwarz RH 56 cm
KS Cycling Urbanbike »FWD«, 21 Gang Shimano Tourney Schaltwerk, Kettenschaltung