Post Slips or Clicks/Creaks.

jedi_master

Having issues with the seatpost on my brothers bike. Been happening for a while.

He has a Ragley Piglet 2, post is truvativ and the clamp is a chromag QR clamp. So steel frame, alu seatpost.

Here's the issue. If you put a very small amount of grease in the tube to stop creaks and to stop it seizing the post will slip, even if you tighten the clamp really tight. (after closing the leaver, using a hex key to tighten more.) When over tighened it still slips, although a lot slower. If you don't put any grease, usless you do it up really tight it goes down very slowly. With no grease and doing it up really tight it stops sliping but will start to click/creak, plus with no grease it has seized in the winter and needed a lot of force to get out.

Any ideas? would carbon assembly work?

The Rookie

Carbin assembly paste is the way to go.

Additionally is the slot in the frame aligned with the gap in the seatpost clamp (wrong) or 180 degrees out (correct)?

Is the post a snug fit in the frame or is the frame oversized/the post undersized so it's a loosish fit?

jedi_master

Yeah the gap is aligned with the cap in the frame. I always thought that was correct. Every bike I see when out and bikes in shops are that way. I know with carbon frames and post it's recommended to be opposite to help stop crushing the carbon, or something along those lines.

Wouldn't say it's a really snug fit but it's not really loose. If the clamp is loosened right off it sometimes will drop part way down without any help. Seat post is the correct size, it's the size ragley listed.

I'll give some carbon assembly paste a try, see if that works.

swod1

On my mega tr when I built it recently. I put a small bit of grease on post and it was driving me mad seat slipping down.

I've wiped off the grease and wiped the post with some gt85 on a rag and it seems to have worked for me but the carbon paste sounds like a better idea.

The Rookie

The gap in the clamp ideally shouldn't align with the gap in the frame, this will tend to pinch the ends (of the frame) in rather than getting even radial compression.

Some bikes have the slit at the front some the slit at the back yet everyone puts the clamp with the gap at the back without thinking, in many cases it's not that critical but steel being stiffer (than the more usual aluminium) and it sounding like the fit is marginally on the loose side you really want to take every advantage you can.

philcubed

The Rookie wrote:

The gap in the clamp ideally shouldn't align with the gap in the frame, this will tend to pinch the ends (of the frame) in rather than getting even radial compression.

Some bikes have the slit at the front some the slit at the back yet everyone puts the clamp with the gap at the back without thinking, in many cases it's not that critical but steel being stiffer (than the more usual aluminium) and it sounding like the fit is marginally on the loose side you really want to take every advantage you can.

Cheers Rookie. Just tried this today, 5 years of creaking seatpost solved! No more explaining to others that my frame isn't about to snap, it's just the seatpost creaking!

The Rookie

Glad to be of help!