Trek seat mast cap - other alternatives
 

I have one of the new Trek Domanes. It, and at least some of the Madones, have a "seat mast cap" instead of the traditional seat post. The seat mast cap just goes over the top of an extended seat tube and has a head that fastens to the saddle rails. While it comes in a couple of sizes it is much shorter than a seat "post."

My problem is that Trek's (read Bontrager) seat mast cap just will not fit a particular saddle that I have. Also it does not offer the adjustability of some seat post heads that I have seen. For example, I have seen seat posts that have a thumb wheel that allows fine adjustments of the saddle angle.

Does anyone know of an alternative seat mast cap, by any manufacturer, that would replace the Trek / Bontrager version. I have searched, but without any success.

Trek does make a variety of "ears" for those, to adapt them to a variety of saddle rails. What dimensions are your rails? Also, they have infinite tilt adjustment with no detents, so you can fine-tune the tilt to absolutely any angle you want.

Thanks for the reply. Actually I have all three sizes of the "ears" that Trek / Bontrager makes. The saddle that does not fit (a Fizik Kurve Bull) has 7x9 mm rails and I have the ears of that size. The problem is that the rails on that saddle are so increditably tight when placed on the head that the compression fittings are squeezed to the point that the saddle is not adjustable. And this is without tightening the bolt at all.

I guess that one could make the case that the problem is with the saddle not the seat mast cap but I really like the way that saddle feels on long rides. While my question deals with the seat mast cap rather than the saddle I will mention that the rails on the Fizik saddle (the way the rails are made) do not lend themselves to being pried apart a few millimeters.

Chuck, did you resolve this? I am e-mailing back and forth with trek and bontrager, but they seem unaware of the problem. It seems like cups with just a millimeter or so of less material would solve the problem. I don't get why fizik made the rails on this saddle so incompatible with everything...