Here is a high poly model of an iconic bicycle design, the Raleigh Chopper Mk2.
The model is 314k verts, 283k faces and in the correct environment will render near photo realistic. It is set up for the Cycles (pardon the pun haha) renderer, with all image textures packed into the .blend file. There is also a small HDRI in the file too but this can be swapped easily enough. I have parented all of the bicycle parts to the seat.
The model is made to real world scale.