No details because I’m waiting to see what the manufacturer has to say, but I’m baffled by it. It’s a seat post. Any ideas?

IMG_1443 by PeterPoddy, on Flickr

Road salt?

Is that what they call carbon ‘delamination’?

wrong type of grease – it’s started to delaminate?

ali post in a steel frame? bit dry and the anodising comes off exposing bare metal underneath and causing bimetallic corrosion, maybe?!

Or is it carbon and wrong type of grease used, and delam? cheap carbon?

If you take iron tablets ,your pooh looks like that.

Guinness poo

carbon

Nope

in a steel frame?

Nope

I would go for a mixture of what GT and Waswas said 😯

Edit > is that an alu post from a carbon frame then ?<

what frame material, post material and grease if any used? and wheres it been ridden? we need details 😛
no need to mention manufacturers as still at warranty enquiry stage 😉

I’d be more worried about the state of the inside of the seat tube…

+1 how is the seat tube looking?? 😯

Ally post
Carbon frame
Ridden in the South, mainly Tunnel Hill, South Downs. Once in the Peaks and once in the Qs, and a few times in the Purbecks and Chilterns IIRC
It’s hardly been ridden since June as I broke my ankle then it rained for 6 months
I generally don’t grease seat posts and no info was supplied suggesting that I should, but I do clean them.

I generally don’t grease seat posts

you will now…

carbon post for carbon bikes! No real issues then.

I’d put money on the anodising being faulty then, got any picture with it clean to have a look at the state of the metal underneath?

Why no grease?

Carbon paste in future eh 😉

ah ,so it could be that the frame tube was de-laminating because of some contamination coming from the post.

By the looks of the machined ribs it could be a Thomson seatpost?
I’ve never seen a post do that before, im guessing its out of your c456?
Bit of an odd one, looks like the surface is flaking off. I’d be inclined to send that pic to the manuf to look at.

LoCo, that IS clean!

I’d be more worried about the state of the inside of the seat tube…

Inside of the seat tube is utterly perfect, but thanks for shitting me up! 😉

Weird, what’s the bb shell like as would give an indication if anything has got in and caused the issues.

so it could be that the frame tube was de-laminating because of some contamination coming from the post.

No. That’s not off the frame, it’s like the ‘machined surface’ of the post is flaking off, like fish scales.
It looks like some form of corrosion of the alloy.

I do clean them.

with Cilit Bang?

looks like aluminium to me, was it in a carbon frame? But could happen in a normal frame, does it get moved up and down a lot? Do you want a PDF on aluminium corrosion?

Aluminium forms a self coating of Aluminium oxide, if this gets rubbed off it will do it again and you can get this type of pitting.

Alloys are more susceptible to corrosion than pure aluminium, and you can get bimetallic between two aluminium alloys.

Tell us more..

LoCo, BB shell is a sealed insert with no access that I can see to the seat tube.

I generally don’t grease seat posts

you will now…

No, I won’t. I’ve had more bikes than I can count and never and never had any sort of seatpost issue. But I won’t be buying this again. 🙂

[makes note to check greaseless/ pasteless ally post in carbon frame when gets home]

Easton post?

If it’s a weird oxidization happening ,it may be down to the way that the post is manufactured,but it still looks like it has had some sort of contamination to start it off.

What post is it?

with Cilit Bang?

LOL! 🙂

Nope. Just the same soapy water I clean all my bikes with. I don’t even use Muc Off and the like very often.
I do move the post, but not often. Only to get the bike on the bike rack usually. Maybe once a month?

The black anodising had sort of gone all ‘soft’ and was rolling up in chunks, like dry skin when you soak your feet (Mmmm nice…) so I thought I’d clean it off, and found this.

It might be down to thermal stress too, the alloy has a higher coeff LTE than the oxide/anodizing but it needs to get pretty warm for this to happen..

What post is it?

As OP, I’m not saying until the manufacturer gets back to me.

To be frank, I don’t actually give a rat’s ass about it. It’s just annoying.

What post is it?

If the anodising was rolling up in chunks,then it probably is an Easton 😉

Wheres the picture gone?

Dunno

IMG_1443 by PeterPoddy, on Flickr

Handily I have a rather nice Race Face post spare.

Detergent from the rear windscreen wiper eating away at the alloy?

My guess would be galvanic corrosion. It happens when you put Al and carbon together. In all serious applications one would apply a glass surface veil to any surface in contact with aluminum. I would be surprised if there was a surface veil on the inside of your seat tube.

Another though, probably the OEM will not know what it is. You would be surprised how little they know about material science 😕

I believe the BB insert is wrapped in GRP to isolate it from the carbon and would expect the head tube to be too.

For the record I’ve had a Thomson post in my C456 for 2 years. Don’t take it out/move it often but it’s absolutely perfect. Need to remember to put some assembly paste on the Reverb before I take it out properly.

My guess would be galvanic corrosion. It happens when you put Al and carbon together. In all serious applications one would apply a glass surface veil to any surface in contact with aluminum. I would be surprised if there was a surface veil on the inside of your seat tube.

Another though, probably the OEM will not know what it is. You would be surprised how little they know about material science

CanI quote you on that? 🙂

But no, in this case I wouldn’t be surprised how little they know in the slightest, if I’m honest.