Looking at a carbon seatpost for a light xc/enduro build…….re they worth it over a alu post….ride in the nw/yorks dales so what is durability like?

Had one on my Marin MV a few years ago and apart from teh dirt scoring the outer surfaces was fine and dandy 🙂

My Bontrager one is holding out

Bontrager ACC (Alumimium core construction) have an aluminium core to give them a little backbone, I think so they'e more likely to bend than snap straight away. a 27.2 400mm one is 240grams I think (£60 RRP) so not weighty as a consequence

If you use the Pace Carbon Grease (reapply every so often, when it gets a bit sticky) then it stops/reduces the surface from peeling away a bit. Makes it much smoother to drop/raise the saddle too.

Definitely worth it. 240g isn't light though, I'd use a Thomson over a Bonty ACC one frankly.

I use New Ultimate which are <130g for a 30.9×350!

Ritchey are nice too, or you can't go wrong with Easton.

require weird grease and don't like sliding up and down – plus its carbon = aloominum

On my hardtail where I don't adjust the saddle height during a ride and where there is plenty of seatpost showing and its a fairly small diameter, I thought carbon was worth it for taking the edge off the bumps and the low weight.

On my FS bike where I alter the height of the saddle often and where the seatpost has a larger diameter and has less seatpost exposed, doesn't seem much point going for the carbon and I just went with aluminium

NEVER!

The only bike I've run a carbon post for any length of time is my Epic, and the EC70 on that has been fine for several years now. Can't really recall if it felt that different from the Thompson that was on it before.

gw why never????

I use to have one (EC70) on my Whyte but replaced it with a thompson pretty quickly.
No problems with it but it did scratch sooo easily when adjusting height.

Yes if you like to put your saddle up and down I'd stick with alu, if nothing else a carbon one will look incredibly tatty rather quickly.

Yes

Amoeba do a nice alu core one called SCUD (and some numbers), that can be found for £30-40. Claimed weight is 210g. A friend's had one for a couple of years with no problems, so I just bought one for a new build.

I have carbon seatposts (and bars and stems from variety of brands) on all of my bikes both road and off road,
I ride in the Peak District every week as well as around the UK and more recently overseas.
I've not had a minutes bother with any carbon part.

"240g isn't light though"
I know its not, but its an 'entry' level carbon seatpost at £60? Its a 400mm one too so should require some extra beef for the extra extension plus some for the extra internal aluminium
I'm happy enough with it for the £30 i got it for

A 350mm £60 FSA one weighs about 260g I think

"New Ultimate which are <130g for a 30.9×350!"
Whats the RRP on that then? 2, 3 (or 4) times the RRP of the 400mm Bontry ACC?

Had one happily on my Chameleon for ages, that's now on the road bike as there was just a bit too much layback. FWIW, seat posts are the only piece of carbon bike stuff I've ever seen break, one was a USE the other FSA, both snapped at the clamp, both by the same rider…Dunno if that means anything.

So long as you're not a serial seatpost adjuster then IME they are fine

I have one on my SS because I never adjust the post on that bike and it's light as all hell (esp with an I-beam I-fly seat) but on my other bikes I either use an alloy one or a dropper. Not that alloy ones don't wear out if you adjust them 5 times a ride but they're less painful (money-wise) to replace when they do start to slip

I got a bike hut one from Halfrauds 😳 for my hardatil, matched it with a Ti railed saddle and it soaked up the buzz really nicely, was a bit fugly but did the job with no complaints whatsoever.

I've run a relatively cheap FSA carbon seatpost on my hardtail for years, offers a nice bit of flex to provide comfort and as long as your not wanting to slide it up and down lots its fine. I wouldn't use one for a bike where I'm moving it alot though, but then that would tend to be a full sus bike anyway and not as important.