You rent a bike or scooter from individuals not a company. Of course it's a risk for people to rent their bike, travelers might wreck them but there are many more owners ripping off travellers then travellers cheating owners. Don't rent from some gangster type on the corner. The guys that have nothing to do all day but hang out on their bike on the corner are the worst risk. Many are into crime and drugs. The other seedy guys and often the cops will back them up and tourists get robbed and badly beaten all the time. Two main tricks are to overcharge for minor damage, scratches etc. Sometimes those were there before you rented the bike but try and prove that when surrounded by a gang screaming at you in their native language. The other trick is that the owner uses his spare key to steal his bike back from you shortly before you are due to return it. You then pay as much money and things (like a camera etc.) as you have to replace his "stolen" bike or you risk getting beaten. What can you do? Try and rent from a reputable shop or hotel owner, they have a reputation to protect. Rent your bike for a few days longer then you actually need it, pack up and return it on your way out of town. They can keep the extra few days rent, it's cheaper then paying for a whole bike. Go with friends when you return your bike so there are witnesses in case people try and strong arm you. Make friends with some nice locals so that people will want to help you not be glad you are in trouble because you are such a jerk.