i know what the difference is dude, been riding for about 15 years and my dad had mopeds (fs1e) before me. i have a pc50 (moped) on here, just asking on behalf of a friend. he's been looking at different scooters but he's to short for the new skool ones like gilera runners, but he wants a 125 or more power from a 50. so as the sh50 is the only one he can fit on he needs more power from that. hes been riding it in stock 50cc form for the last 2 years and he's 20 now so wants a bit more grunt. :)