We have got you covered on seat post for your bicycle. From longer to wider, we have the right size for you. Looking for the newer drop seat post to upgrade your mountain bike or new stealth pivotal seat post for your BMX bike, we have all the original seat post that is available. The first thing you need to know to upgrade your seat post is what size seat post do you need. Just check your current seat post, and most of the time, the size is inscribed on the lower part of the seat post.