My Folding Bike Seat Post always slips...

[BikeLifePinas]

You know that feeling? happily pedaling away and then...

*SCHHHHWEEEP!!!*

I felt like a lowly person (literally)

any help or ideas on how to solve a slipping seat posts? it's so annoying and I don't know how to solve it.

 

[Fab Foodie]

What folding bike?

Degrease/clean the seatpost and if the post is removable, the inside of the frame that clamps the seatpost.
Then qdjust the clamp so that it clamps harder onto the post when closed. Should be an easy adjustment.

 

[jefmcg]

Do you grease the seat post? Start by not doing that. My Mezzo and my partners Hoptown both explicitly say not to.

 

[Kell]

It's possible with a Brompton to over-tighten it so be careful.

You may or may not want to do this, but I roughed mine up a bit with some sandpaper.

Completely solved it after that.

 

[BikeLifePinas]

Do you grease the seat post? Start by not doing that. My Mezzo and my partners Hoptown both explicitly say not to.

I don't grease it.

I've also made the clamp a bit tighter, being careful that I don't ruin the thread.. but.. it still slips.. waaah!

 

[BikeLifePinas]

It's possible with a Brompton to over-tighten it so be careful.

You may or may not want to do this, but I roughed mine up a bit with some sandpaper.

Completely solved it after that.

I may have to do that as a last option. I'm using a CRIUS and the Seat post has paint.

 

[simon.r]

IME with a Brompton it's a very fine line between the QR being tight enough to stop the post slipping and too tight to allow easy folding. Trial and error and adjusting the nut on the QR literally by a 1/4 of a turn at a time eventually found the happy medium.

 

[reppans]

What folding bike?

Degrease/clean the seatpost and if the post is removable, the inside of the frame that clamps the seatpost.

This worked great for my Brompton too.... I use alcohol to degrease.

I don't grease it.

If you touch your seat tube with your bare hand, you're effectively greasing it.

 

[oldwheels]

Simon.r has the same solution as I used. Position seat post and lock then tighten very slightly with an Allen key. Keep doing this until it stops slipping. As said tighten slightly a quarter of a turn at a time until right.

 

[Ridgeways]

Not that I ever had a slippage problem with the seat post on my Bickerton, but in order to ensure that I never had to guesstimate the correct position/height, I inserted a screw at the required position, the head of which fit within the slot of the supporting post under the clamp, so that the exact same correct position could be instantly achieved every time, which also means that it is impossible to slip down whether clamped loosely or tightly.

 

[bonzobanana]

You can also double clamp by getting a second clamp that fits onto the seat post itself to make it much harder to drop even if it doesn't prevent rotation. On this clamp because it doesn't go into the tube of the frame you can use a rubber liner between clamp and tube to make it much harder to slip. Or get a purpose built double clamp and add quick releases to it if possible.

 

[Kell]

I'm having the other problem at the minute in that mine is starting to stick.

I'm going to have to have a look at the seat tube at the weekend as there might be grime in it.

 

[steveindenmark]

Cut a very fine piece of inner tube and put it on the inside of the QR before you tighten it. The rubber will stop the stem from slipping.

 

[Salty seadog]

Would carbon paste be of any help?

 

[mitchibob]

You know that feeling? happily pedaling away and then...

*SCHHHHWEEEP!!!*

I felt like a lowly person (literally)

any help or ideas on how to solve a slipping seat posts? it's so annoying and I don't know how to solve it.

When I first picked up my bike, I had this very same problem. Every bump I was going down a millimetre or so, so that I had to stop and lift the seat every 5 minutes. I tried just adding a quarter turn to the nut to see if it helped. Still slipped. A couple more quarter turns and made it so that seat stayed up, but the plastic clamp couldn't turn the nut, and was totally useless. This was in the first few days of ownership, and something I'd never experienced with a rental.

I took it back to the shop I'd bought it from and they just replaced the clamp in about 15 minutes for free, and it's been fine for about a year, although slipping very slightly now again. I'm going to stick an 1/8th of a turn in it tomorrow and see how it goes. I guess it's quite exacting on how much torque needs to go into that bolt to allow it to do what it does.