SL8 look alike seatpost wont hold in place

[gandalftw]

Hi,

I let this build at my local bike shop 3 weeks ago and I cant seem to make the seatpost stay in place , I added more carbon paste today and will check if it holds tomorrow.
Any known solutions or someone already encountered that ?

[Sander2177]

Hi,

I build this bike 3 weeks ago and I cant seem to make the seatpost stay in place , I added more carbon paste today and will check if it holds tomorrow.
Any known solutions or someone already encountered that ?

What torque are you tightening to? 6.2Nm?

[gandalftw]

I am sorry to say that I don't have any torque wrench, just by feeling

[gandalftw]

I have a 25e torque wrench which is not good , I will take it to the bike shop to torque it there, suck as a rider ? what this have to do with anything ?

[Avalius]

How much carbon paste did you add? Clean everything and try adding "alot"?

[gandalftw]

I did put a lot today since there was not much in there since it was built. I can only check it tomorrow. I closed the screw like in my older bike I have (gently without over tightening). I travel with my bike once or twice a year and never had any seatpost falling down before, by the way it falls after some time (5cm down) during the ride not immediately.

[Sander2177]

I am sorry to say that I don't have any torque wrench, just by feeling

What!! 😄
Crazy guy!

Man, you need to use a torque wrench on these carbon bikes — 6.2 Nm is tighter than you think!

I don’t touch any bolts without one. Thru-axles maybe, if I get a flat and need to tighten by feel on the roadside, but otherwise, always use a torque wrench.

I also check all bolts frequently since vibrations can cause them to loosen over time.

It’s an accident waiting to happen without one — even if the frame isn’t a genuine article!

[Sebastian]

Does the seatpost fit snugly or can you wiggle and tilt it from side to side when not clamped down? I’ve found that even with high torque, a bad fitting seatpost will slip over time. If that is the case, increase the seatpost diameter in the right places with some sort of tape. I usually use something textile based. Also, I add grip tape onto the seatpost clamping wedge to give it the maximum amount of friction. But do only do that if you’re sure the seatpost doesn’t wiggle around. Otherwise the grip tape will work its way into the seatpost like sandpaper. And lastly: Put Loctite on the screw in the seatpost wedge if you find that it loosens over time.

All these things together usually work for me.

[gandalftw]

Thanks , the seatpost doesn't wiggle at all. I really hope its a carbon paste/torque issue, I will check tomorrow and update.

[mozart]

i bought used original seatpost and i solve all my problems. no flex and stay in place without carbon paste. original is stiffer, thiner and lighter.

[Avalius]

i bought used original seatpost and i solve all my problems. no flex and stay in place without carbon paste. original is stiffer, thiner and lighter.

Do these fit the replica's?

[mozart]

Do these fit the replica's?

yes. the outside dιmensιοns is the same. many people have problem with replica seatpost. is very soft. that's the reason doesn't stay in place. original seatpost makes bicycle stiffer. i m 80 kg and i have much flex in tail

[Sander2177]

No issue with the seatpost I had in the X68 torqued to spec with some carbon paste all good!

[SirBikealot]

how does the clamp look like? On my TT-X34 it's a three piece clamp with a single blot. And this mf slipped on my first ride no matter the torque. The solution was to take it apart and apply the carbon paste direct onto the bolt! Since then no more slips at all.

[gandalftw]

A good amount of carbon paste with a cheap torque wrench and so far so good , the seatpost is holding.
I didn't suspect it's a frame/seatpost issue since I know the seller for 10y+ and had 8 frames with no issues at all, this is the first one I use for myself.
Thanks everyone and hope it wont move again