Is it permissible for an unmarried Muslim woman living in a non-Islamic country, who has a child and works to cover his expenses, and does not have enough money to buy a car, to use a bicycle for transportation and to attend to her needs, especially in the summer when walking is difficult?

It is permissible for a woman to ride mounts, but riding a bicycle in front of men is not permissible except out of necessity or dire need, provided she wears modest clothing that is neither form-fitting nor transparent, and that she is careful not to expose any part of her body while mounting and dismounting. Among the conditions of hijab (definition) is that it should not be attention-grabbing.