1) Kvartal Wall Fittings
The first space saving solution may be not the most attractive but it’s the cheapest. IKEA is possibly have everything you could ever want for your house in one store. If event they don’t have something you need, you can just use some of their cheap parts to make it with your own hands. Thomas Stegelmann created this wall mounted bike rack hack using Ikea Kvartal wall fittings (which cost $4.99 each only). Using his tutorial you can hang your bicycle vertically by it’s handle bars in a closet. Securing your bike in place using minimal amount of space and efforts.