(FEB !8, 2010. TOPIC SHOULD BE DELETED BY A MODERATOR, Robert.) I bought a used Strong Bicycle GTS210. Want to learn the hub motor specs,is it worthy of upgrading (to 400-500W @ 36V), and is it geared? Hub has a Z in a circle, circle is broken on right side, Z could be an N, Has serial DB66030327G. Frame spread is 175mm, overall diam. of hub is 129mm. Has 7 sproket cassette AND 180mm 6 bolt disc on left side.Contoller is tiny, BRUSHED 36V, 250W at 18A, 500W peak. http://www.strongbicycle.com site states they make 300 types of ebikes. English version is just a translate...sign up doesn't help. Thanks for your input. Robert.