I'm not sure where to post this, but it looks like C&V has the most posts about B17s (Brooks, not Boeing), so....

My problems are too much weight on my hands and pedaling on the nose of the saddle with my B17 Imperial. I'm much more comfortable, and maybe even faster, with an old Fizik Aliante for 5 miles or so; then perineal numbness sets in. I attribute the weight on arms/pedaling on the nose to the lack of setback with the B17.

Per the Competitive Cyclist calculator, my seat to handlebar distance should be in the 53.5-56.6 cm range. In my setup, the Aliante gives 54 cm, but the Brooks gives barely 50. I've also estimated the handlebar to sit-bone distance; 75 cm on the Aliante and 73.5-74 cm on the Brooks. It seems much easier to engage my core to hold myself up (weight off bars) with the Aliante, even though I'm slightly more stretched out.

My seatpost is a 40+ year old Zeus copy of the Campy 2 bolt post, which appears to have some setback - 1"? -, not enough in any case.

If you had this problem, or something like it, how did you solve it?

Has anyone here used the plain seatpost + clamp + Brompton 'saddle adaptor pin assembly' (for example, http://clevercycles.com/saddle-adaptor-pin-assy)? How has that worked for you? It looks like the cheapest way out ... unless I buy a new saddle and sell the Brooks. And the Aliante.

My seatpost 27.0 mm, which makes something like the VO offering a nogo.

I now weigh 225, BTW. Brompton recommends against using their part to extend reach, and I wouldn't use it that way on their bikes, but I think there's a good chance it would work for me. I'd rather not be a pioneer though....

Thanks in advance.