Layback and inline seatposts

Giraffoto

I don't know what the advantages and disadvantages of these might be - when is it better to be 10 - 20mm further back, and when is it better to be further forward?

cooldad

The only use is to get the saddle where you need it. There are no inherrent advantages as such, although an inline post make be stiffer/stronger.

paul.skibum

If a bike is specced with an inline, a layback post might give more room in the cockpit but it might screw up the pedalling and handling by putting you too far back to be efficient pedalling and unweighting the front wheel a lot on steep climbs.

An inline put on a bike with a layback post will shorten the cockpit and shift you forward for climbing and pedalling and may make it easier when off the seat to get weight back by putting the seat out your way a little.

if messing with your cockpit and available space is something you are thinking its worth changing possibly but otherwise I'd stick with what is on there.

The Rookie

The other aspect is that with a layback post you effectively have a longer bike when sitting than when standing on the pedals as the BB to front distance doesnt change when the saddle moves back (going from an inline post), so you can use that effect to make a shorter trail HT into a longer XC bike when sitting (Slighlt exageraion, but I hope you see what I mean).