There are a few standards when it comes to how a front derailleur is mounted to the bike, the most common one being clamp-on. The clamp-on derailleur is secured to the bike's seat tube using a simple warp around clamp. Front derailleur clamps are designed to work with seat tube diameters of 28.6, 31.8, 34.9 or 38.2mm, however, most clamp-on derailleurs come with shims in order to accommodate multiple seat tube diameters.
the “big wheel” comes with several advantages over the conventional 26-inch wheel, offering higher speed and better stability. Physics provides us with sufficient answers when discussing the 29 inch wheel issue.