A chain is only effective if it is in the correct chain tension. A too tight chain is very heavy. A slack chain tension will run off during the cycling of the sprockets and eventually get to the bottom of the chain guard. The chain should be in order not to run off have a height clearance on the underside of about 2 cm.
Ordinary chain is tensioned with chain tensioners, which are hooked to the shafts and tighten themselves against the end of the dropout. Make sure when tensioning the chain, that the chain does not get too tight, and that the lug nuts are loosened. After the axle nuts are tightened, the nuts of the chain tensioners must be tightened .
Missing the chain tensioner, the chain can be tensioned by moving the rear wheel in the dropouts back. The axle nuts must then be secured with good retaining rings and tighten the nuts with the right moment, in order to prevent the wheel from being skewed by the chain.