slipping seat post

[Ranger]

Any ideas on how to cure this?

I am doing the clamp as tight as I dare and am about to resort to gaffer tape around the post in an attempt to stop it slipping but any other suggestions gratefully received

 

[Mr Pig]

The tape won't work.

It has to be a poor clamp or too small/smooth a seat post. I had this problem, tried a lot of things but was only sorted with a new seat post.

Many cheaper posts are extruded metal tube, so they are relatively smooth. Most dearer ones are turned. As well as making the size more accurate the turns act like threads and give the frame something to grip on.

If it's a new bike just ask the shop to sort it out. It's the manufacturer's fault.

 

[Zippy]

Think yourself lucky it slips and is not frozen in the frame! (See other threads).

How's about forming a shim out of a piece of a drink can to tighten the post in the frame and the bolt around it?

Having said that, if the stem is so loose as to be fluting the frame as you ride, it is time for a new seat post of the correct diameter for the frame.

 

[numbnuts]

I use a jubilee clip on the seat post and then tighten to post to the frame

 

[tyred]

I use a jubilee clip on the seat post and then tighten to post to the frame

Excellent idea. I must try this on my Pug. I can't buy a new seatpost in a strange French size.

 

[NickM]

Excellent idea. I must try this on my Pug. I can't buy a new seatpost in a strange French size.

(to the jubilee clip, not the Peugeot)

Can you not get an undersize seatpin and an appropriate USE shim?

 

[NickM]

Any ideas on how to cure this?

Yes - this stuff

 

[HJ]

Yes - this stuff

+1

 

[Mr Pig]

Excellent idea.

It might not be. The clip might trap water under it and corrode the post enough to cause a fracture. I don't think you want to do anything that might scratch or pit an aluminium seat post.

 

[tyred]

It might not be. The clip might trap water under it and corrode the post enough to cause a fracture. I don't think you want to do anything that might scratch or pit an aluminium seat post.

Mine is chrome plated steel

 

[Mr Pig]

Mine is chrome plated steel

Rust? ;0)

 

[tyred]

Ideally, it would rust solid in the frame so it doesn't move...

 

[bigtoe]

Maybe its not the right size.

 

[swee'pea99]

Excellent idea. I must try this on my Pug. I can't buy a new seatpost in a strange French size.

It'll come up on ebay sooner or later. Just do a search for it, specifying the exact size and making sure to tick for 'search title and description', then 'save this search', then their system will run that search for you every day and email you when it comes up.

 

[Jonathan M]

I had an MTB frame once (steel) where the braze ons for the seat binder bolt were not parrallel with each other. The result was that it was near to impossible to tighten sufficiently to hold the post. I eventually got the frame resprayed and had the company doing that remove the binder bolt bosses. I then used an external clamp with QR and that did the job nicely.

If its a steel frame then it may be worth checking the binder bolt bosses, if present, are positioned correctly.