A bicycle jersey can be bought either offline or online. There are many bussinesses online that offer all sorts of sport's products, including bicycle jerseys. Offline, you might be able to find bicycle jerseys in your local sport's store.

Bib cycling shorts for men can be purchased at most outdoor gear stores, such as MEC in Canada, or REI in the USA. Bicycle specialty stores also sell bib cycling shorts from a variety of brand names.

What you want for cycling is shorts/trousers with as little seams and as flat seams as possible between your body and the saddle. Bicycle shorts are made that way, and they are also padded - but any shorts that fits the bill of being flat and friendly to your skin will work.

The noun 'bicycle' functions as the subject of a sentence or clause, and as the object of a verb or preposition:

The red bicycle was very cool. (subject of the sentence)

I bought a basket for my bicycle. (object of the preposition 'for')

The noun 'bicycle' used as adjective, called an attributive noun:

There is a bicycle lane on the road where I live.

The word 'bicycle' is also a verb:

We often bicycle to the library.

They are different because shorts are longer and boxer shorts are shorter. Boxer shorts look cooler.