Clean the bike
Clean your bike thoroughly and dry the entire frame and all the components with a rag as crusted mud on the tubes or deep in the components is the last thing the bike deserves.
Clean and lube the chain
The chain should be cleaned properly by using either a bike chain cleaner that you can get from 10 euros or special washing brooms that are offered in a variety of sizes. A small hand broom in cooperation with an old toothbrush can do the work too.
Fight the humidity
The environment in most cellars is rather humid, which might render a mixture of rust and mildew on the components and the frame scratches alike. To prevent material degradation, wipe the frame tubes with a cloth moistened with silicon oil. This procedure should conserve the bike through the winter. On top of that, grease the chain as if you wanted to ride out in the rain to keep it protected against air moisture. You also might cover the bike with a blanket to hide it from air dust that would mingle with the oil layer and generate a slimy mess.
Don’t let the tires perish
Should the bike stand on flat tires for a long time, the rubber material would degrade and perish the same way as if a car was left with empty tires – its weight would eventually press the rims through the rubber. To prevent that, inflate both tires completely and check them once a month.
Store it where you live
The best place to store the bike is in a dry place in your flat with a constant temperature not dropping below 19°C. If your flat is big enough, you can easily skip most of the preparations as both cold and humidity have no chance to make any damage. The chain shouldn’t be greased as it might soil the floor or furniture.
Make the servicing now
If you want to have your bike ready as soon as spring comes, late autumn is the best time to bring it to the bike shop and let all the maintenance be done. While in spring the bike shops are under attack of cyclist and bikers craving to have their first sunny ride, in autumn and winter the waiting periods are short and most of the commissions can be completed within just a few days. Even though most people are putting off bike service until spring, the early maintenance will pay off.
Keep it in the bike bag
Some people prefer to remove the wheels and dismantle both handlebars and the seat post and put the bike into a bicycle bag for the whole winter. This solution is a space saver and keeps the bike well preserved.