Spin bikes target more muscles than upright bikes. With a spin bike, you'll be working the glutes, quads, hamstrings, calves, core, shoulders, and arms. An upright bike only works the glutes, quads, hamstrings, and calves. Spin bikes have a heavier flywheel than upright bikes and are smoother to ride as a result. And because it takes more energy to turn the flywheel, you burn more calories than you would on an upright bike. Most spin bikes don't come with an LCD monitor, while all upright bikes come with one. Upright bikes have a bigger and more comfortable seat than spin bikes, so designed because, on the upright bike, you'll be seated most of the time since the bike is not optimized for cycling while standing, while on the spin bike, you spend less time seated and more time standing and jumping. Finally, spin bikes are more expensive than upright bikes.