My original idea for the bike was to use only outdoors. But after I finished the bike I noticed that it would also make a great indoor workout machine. So I also designed a special base for using indoors. This base has bars called holding bars that are on both sides of the wheel so when you pull the bike on the bars it stays there. There are also two wheels touching each wheel of the bike. The wheels are connected through the chain and switching gear. So when you are using your legs to ride at the same time your handle bar moves through the chain or when you move the hands your legs move at the same time. This provides very good exercise for the indoors.