Brommie - slipping seat post

[Yellow Fang]

I have a problem with my Brompton. The seat post keeps slipping. By the time I've cycled the three miles from the station to work, it has slipped about two inches. However, if I tighten the nut sufficiently to stop the slippage, I cannot fold and unfold the bike. Does this indicate some difficult-to-fix problem in the seat post collar? It looks like I will have to spend some time and money replacing many of the parts. If I cannot fix the seat post problem myself then I might just ask the bike shop to do it all.

 

[TheDoctor]

Have you tried cleaning the seat post?

 

[shouldbeinbed]

^ +1 and inside the seat tube.

 

[Yellow Fang]

No, I'll give that a try.

 

[TheDoctor]

It worked on mine

 

[Kell]

Mine slipped when the bike was new - I think it might have been too clean.

I did read about people putting another seat clamp on the seat post itself, and clamping it tight to stop the seat post from going in to the seat tube, but I just tried scuffing the seat post with some sand paper.

This completely cured it for me.

Though it does mean your shiny looks a little less shiny.

 

[Kell]

It would take a little longer, but probably no more than having to undo two on telescopic seat posts.

I think the idea is that you add a QR seat clamp. so you undo two and the seat post slips through it.

Seemed a bit of a faff, but it was next on my list if the sandpaper trick didn't work.

 

[Yellow Fang]

I don't really like the idea of sandpapering my seat post. I could use an extra QR clamp, but I don't really like that idea either. I have seen posts on other site which suggested friction paste. Has anyone heard of this?

 

[Kell]

Are you still suffering?

 

[Yellow Fang]

Are you still suffering?

Yes, although I have been replacing lots of parts on it recently. The seat-post problem is the last thing.

 

[Bromptonaut]

The clamp itself can wear over time due to the locking cam inside losing its profile. Replacements are available.

 

[Kell]

well. mine's not been a problem at all since the sandpapering...

 

[jay clock]

I had the same problem on day 1. Solved by tightening the hex nut. Are you sure you have tried this properly?

 

[Yellow Fang]

I had the same problem on day 1. Solved by tightening the hex nut. Are you sure you have tried this properly?

I have tightened it and loosened it several times. If you tighten too much then you cannot open the clamp.

 

[jay clock]

I have tightened it and loosened it several times. If you tighten too much then you cannot open the clamp.

go back to the shop