Superglue and carbon fibre…

OK so I bought a carbon seat post off eBay. It was cheap. It’s Ritchey branded, but clearly not original.

The clamp has one bolt that goes all the way through and tightens up both sides, clamping the seat rails. This is inside a circle of carbon fibre and pushes into a wedge, which wedges into this hole. Now, there is nothing to stop the seat angle changing. For example, sit down on the seat and go over a bump, hard, and the sit tips forwards or backwards depending on where the weight is. I have tried tightening the bolt up as much as I dare. I’ve used a variety of Loctites, given them a couple of days to harden/set. I’ve tried carbon paste. Nothing seams to keep it in place. The wedge either side of the rails that goes into the circle of carbon, is plastic. The post is clear coated but NOT inside this circle.

Now ultimately I know the answer is to get rid of this and buy a proper post as worse case scenario I’m heading to A&E to have shards of carbon removed from MY ring piece. But I’m a stubborn sod and I want to make it work. As posts go I find it really comfortable and as long as I don’t forget about the fact it moves, I can cater for it’s inadequacies.

So, would something like Gorilla glue or just a double-hard b@stard super-glue hold the plastic into the post. Or should I stop being a plank and cough up for a new seatpost that’s better designed and will do what it’s meant to do?

(If anyone could suggest a 27.2 400mm post then please do! Or should I just sack off carbon, get a Thomson in silver and live the rest of my life in blissful ignorance with an intact sphincter?)

Have you tried adding a spoon to it?

No, the Bel Air is fine. It’s the post not the saddle that’s the problem.

😉

Carbon paste worked on my USE sumo which is a similar setup, it’s got little granules in it that bind it up and stop it slipping..

How the hell can you tell if a seatpost is comfortable?? Surely unless you’re some kind of princess and the pea type character you can’t claim to feel the difference between seatposts!?!
I would get a decent non-carbon seatpost, the weight difference is minimal anyway. My Thomson seatpost seems quite comfortable insofar as the seat stays where I put it…

Well, since you asked. The alloy post I had before was solid, didn’t budge and quite harsh. The carbon feels comfier when I’m sitting down and riding. Not scientific but I can tell the difference.

In much the same way as people find various bike parts suit them better – like how people prefer alloy over steel over titanium….

HTH?

+1 for carbon paste.

How the hell can you tell if a seatpost is comfortable?? Surely unless you’re some kind of princess and the pea type character you can’t claim to feel the difference between seatposts!?!

Theres some huge differences, especialy some of the clever designs that use some basalt fibres to add damping, like canyon. There’s (allegedly according to the graphs, they’re german, yheres always a graph!) more movement in my roadbikes seatpost than there is cushioning on my saddle!

I would get a decent non-carbon seatpost, the weight difference is minimal anyway. My Thomson seatpost seems quite comfortable insofar as the seat stays where I put it…

The weight difference is minimal, it’s the comfort that people are after with carbon posts.

Buy cheap, buy twice.

Back to the OPs question… I’ve used superglue to stick rubber edging onto carbon fibre fins, so I reckon it’d stick your plastic as well.

I can see the idea that carbon fibre absorbs shock but underneath a saddle that itself is flexing? To be fair I don’t ride a hardtail, maybe you can tell the difference then. I can’t imagine it making much difference to a full suspension bike but I’m sure people will disagree!
If its fake I would be as worried about the whole thing snapping one day as I would about the bolt.
On a possibly useful note would some sort of thread lock adhesive maybe work? They’re methacrylate based so similar to superglue, but stronger I think.
The problem with any effective adhesive would of course be that if it really works the seat is then stuck on…!

Kind of a forever bodge http://www.itwplexus.co.uk/plexus/products
560 or 590 would work

Get a new one. Just bought a 2nd hand KCNC scandium post for £40 – you can have it for £60 if you want! 😉

Sounds good, drop it off to Australia for me. 🙂 I’ll be at work at 3 so see you some time shortly?

I had a specialised alloy post of that design. Did the same thing.

carboncycles.cc have some cheap carbon posts.

Glue would work, I’d go with a 2k epoxy/amine like araldite but you still risk it going if you sit down hard.

I have a Specialized post of similar design – also carbon, but with alloy insert at that point. It does have to be done up really, really tight to stop it moving. There’s no way I would risk doing the same with an all-carbon version – especially a “cheap” one.

So I used some Tarzan Megabond glue as my Araldite tube had gone to gunk. Said to allow up to 30 mins to fully set. Left it for a couple of hours and it seems to have stuck fast. Seems to have done the trick.

While touring and having to bodge something similar, I’ve just used grit/gravel from the road and I expect that any similar grit/friction material will do the job too. It’s clearly not a ‘good’ solution as it will mark the surfaces but unless you’re planning to adjust it, it will be a perfectly workable solution.

For a slightly higher tech version, I’ve seen people use swarf.

My Joplin has a similar sounding system and never moves.

I’d send it back myself.