Traditional Saddle Rail Clamp – Steel Guts
This is an older type of saddle clamp that was popular when seat posts were made from steel rather than alloy. Any saddle bought from a bike shop will fit. The general idea is that the bolt goes behind instead of in front of the post, you tighten it up on both sides so that the top of the seat is level and the seat being in the middle of the rails. Swapping over a seat can be a ‘bit of a fiddle’ as there isn’t necessarily a lot of room under the seat to assemble all the bits and keep them in place whilst you do up the bolt.