Black, 31.6 diameter. 410mm long and more than 25mm layback. Any ideas which will fit the bill? I had pinned my hopes on a Thomson but the layback is only (surprisingly) 15mm according to Chain Reaction Cycles.

Thomson with a 10mm longer stem.

^ saddle position/setback is relative to BB, a longer stem will increase reach to bars but wont move the rider any further back.

OP – 25mm is about the most you will find, there may be some models slightly bigger but sticking the clamp more than an inch behind the post poses all sorts of issues with regards to strength and construction that means it is pretty uncommon, not to mention *shouldn’t* be required if you are on the right size frame.

My layback post of choice is always a Race Face XY but they don’t make them any more.

Out of interest, why do you need more, are you trying to squeeze on to something far too small, or do you have some funky seat tube in front of BB style frame that necessitates a lot of layback to get the saddle int he right place?

Ritchey do long posts with 25mm setback. The Ritchey Comp has a version with those dimensions, it’s likely there’s a pricier model that fits the bill too.

The frame is a little small. A touch more height and layback on the seatpost would have it comfy as opposed to ‘not quite’ right.