I'm always looking for a good reversible seat post - one which allows you to use it with either front or rear offset.  Reversible posts are useful to triathletes since we need more posts that allow us to move the saddle forward on standard road geometry bikes to reduce the bend at the waste when using aero bars. 

I recently built up a road bike into a tri bike for my son to race.  Since I needed to move the saddle forward to increase the effective seat tube angle to 76 degrees, I decided to try this new post.   I was particularly interested in the Biposition post because of its adjustability, you can use it with either 32.5 mm or 18 mm forward offset or turn it around and use it with 18 mm to 32.5 mm rearward offset.  For most people, it could be used in the standard 18 mm rear offset position for a road bike and then turned around and used in the 18 mm forward offset for triathlons.

For those of you unaware of Selcof, it is an Italian company specializing in seat posts, stems, bars and headsets.  While I have been aware of the company for quite some time, this is my first experience with a Selcof product.

The post is a very nice, flat black aluminum post with a fixed bolt mounting system.  Therefore, to adjust the mounting position of the saddle (alternating between the two possible positions), you must turn the saddle clamp to the right position on the fixed bolt.  Next you install the clamp around the saddle rails and then install and tighten the removable bolt.  The removable bolt will either be at the front or rear of the saddle depending on the position the post is facing. 

In order to use the post in the 32.5 mm offset position, you must position the saddle clamp near the end of the fixed bolt (it is almost too short for this position).  Since saddle rails are a standard diameter, I am assuming that Selcof is both aware of this fact and satisfied that there are enough threads making contact with the saddle clamp to maintain safety.     I think Selcof could improve this post, though, by specifying a fixed bolt that is 5 - 10 mm longer.  Nevertheless, I have seen professional triathletes using this post with the stock bolt in the 32.5 mm offset position so I am assuming it is safe to use.  It appeared relatively safe to me, but I have no expertise in this field.

Having a good looking, high quality seat post capable of mounting a saddle in four different positions is entirely unique.  If you have the need for either a reversible post to temporarily convert your road bike to a tri bike without changing posts or simply need a forward offset post and aren't thrilled with the few choices available, then you may want to give the Biposition a try.  I am satisfied with the post and intend to continue using it. 

KDG