Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Suspension seat posts - advice please

I'm shopping for a new sportive frame. I'm inclined towards good steel (853) or ti. A friend is trying to convince me that I'l get as good a ride out of an alu frame with carbon forks, stays and a suspension seatpost. I'm not convinced. Leaving aside the question of durability has anyone got any views?

i haven't used a seat like that, but i'd imagine that you'd lose power-transfer somewhere along the way. (like with front suspension)

your friend might be right, but i doubt the suspension saddle would have anything to do with it.

my $0.02

I pulled the suspension post off my bianchi volpe and noticed no difference in comfort, and bike was a lot lighter.

I use suspension seatposts on my mountain bikes. Haven't really seen the need on a road bike.

Totally unnecessary on a street bike. Off-road, sure. On-road, if you want some extra "suspension" then run wider tires. znomit pretty well nailed it: It's excess weight for a negligible comfort increase.

The only benefit to a suspension seatpost is that you can boing up and down on the cheap ones while waiting at a light. :P

...for the advice so far. I'll tell my friend where he can stick his suspension seat post

Yeeeeeaaaahhhh! You tell 'em...

In my experience, suspension seat posts make it hard to adjust saddle height, since there is some variations in saddle height caused by variation in the weight of the rider &/or saddlebag (if used). Plus, extension to pedal will vary over bumps and potentially with pedal stroke, possibly causing adjustment issues.

I agree, suspension through good-quality, high-volume tires is much more effective. But you need to plan ahead and make sure to get a randonneuring / long-distance-suitable bike that has room for those tires (with fenders, potentially). There are lots of good and inexpensive choices available, though, if budget is an issue ... Soma ES, Salsa Casseroll, and of course lots of higher-end stuff.