Cycloalkenes with a small ring have about 20° more bond angle strain than a cycloalkane of the same size. This is because the bond angle for an alkene, C-C=C, is 122°, while the bond angle for an alkane, C-C-C, is 112°. When these carbons form a small ring, the alkene which has a larger bond angle will have to compress more than the alkane causing more bond angle strain.
Cycloalkenes have a lower melting point than cycloalkanes of the same size. The lowered melting point is due to the double bond preventing the compound from compact packing.
Cycloalkenes generally reflect physical properties of their cycloalkane. In physical states, only the smaller cycloalkenes are gases while the others are mostly liquid. These molecules are also more reactive than cycloalkanes due to increased electron density shifts of the double bond.