Seat slipping

[icowden]

HI all,

I have an issue with seat slippage in my trusty Tern Joe (folding bike). The seat has a quick release clamp. The clamp that came with the seatpost broke (the rubber washer got mashed), and I have since got through two more.

I cant get the clamp tight enough to hold the post in place over time (15 minutes over bumps) no matter how hard I try. I'm not light (15st) but not that heavy. I tried buying a graphite based grease, and that hasn't worked.

In the absence of any other ideas, I am now wondering whether it would be worth drilling a hole through the seat post and using one of these to stop the post drop. I don't know whether that would adversely affect the safety and strength of the post.

 

[Smokin Joe]

Put a Jubilee clip (Or any suitable clamp) round the seatpost at it's junction with the tube, that will stop it slipping. I would not drill through the post because of the consequences of any failure.

 

[Slioch]

I've got exactly the same problem with my folder (Raleigh Evo Two). I've tried degreasing the post and torquing-up the clamp bolt as much as possible which improved things slightly, but after 15/20 mins I need to get off and raise it again.

Fitting a jubilee clip is a good suggestion, but the problem I'd have is that I need to be able to drop the seatpost right down for storage, so that wouldn't work for me.

My current line of thinking is to replace the seat clamp with one that is wider in profile so that it covers a greater area of the down tube, thus providing more grip. I'm not sure if this would work or which one to get, so if anyone's got any suggestions then please feel free to chip-in

 

[fossyant]

Better seat clamp possibly

 

[icowden]

siloch - i'm with you. I need a solution which can be added and removed easily as the seat has to go down to fold.
As for a "better seat clamp" my problem is that I don't know how to calculate the right diameter. Tern don't mention the clamp width in the specifications.
There seem to be many variants...

Tern make the TERN OVERLOCK SEATPOST CLAMP but say it is for Verge and Elipse. PLus no-one seems to stock it anywhere...

 

[vickster]

siloch - i'm with you. I need a solution which can be added and removed easily as the seat has to go down to fold.
As for a "better seat clamp" my problem is that I don't know how to calculate the right diameter. Tern don't mention the clamp width in the specifications.
There seem to be many variants...

Tern make the TERN OVERLOCK SEATPOST CLAMP but say it is for Verge and Elipse. PLus no-one seems to stock it anywhere...

Try the Tern Uk distributor?

https://www.bikebiz.com/moore-large-becomes-uk-distributor-for-tern/
https://www.moorelarge.co.uk/

 

[Pale Rider]

I had some success with this Surly heavy duty clamp.

https://www.wiggle.co.uk/surly-constrictor-seat-post-clamp/

 

[Heltor Chasca]

The Thompson seat clamps are designed to be super tight. So much so you can crush the seat tube and seat post so go steady.

 

[Globalti]

Get your bike shop to give you a smear of carbon assembly paste, which is a gritty paste designed to grip carbon seaposts that are lightly clamped. It might make all the difference on your seat post.

 

[Slioch]

Some good suggestions here, but the OP and I need a quick release mechanism for convenience.

 

[rogerzilla]

Another vote for the Surly clamp. Gusset also make a strong one which can be mullered tight.

You should also try the next size of seatpost if you can borrow one - it may be a better fit.

 

[Deleted member 26715]

Carry a small piece of pipe that will fit over the end of the clamp to get extra leverage

 

[icowden]

It was carbon assembly paste that I used. It gave some improvement but not enough.
Leverage isn't an issue - i keep on ironing the washers flat on the clamp.
The Surly constrictor isn't quick release.
Thomson clamps are not quick release.
MooreLarge's website appears to be broken (products won't list under seating).
I did wonder if one of these might work?

 

[KneesUp]

It was carbon assembly paste that I used. It gave some improvement but not enough.
Leverage isn't an issue - i keep on ironing the washers flat on the clamp.
The Surly constrictor isn't quick release.
Thomson clamps are not quick release.
MooreLarge's website appears to be broken (products won't list under seating).
I did wonder if one of these might work?

View attachment 456459

You can but hope.

 

[Smokin Joe]

Forget the quick release and carry an Allen key. It takes a couple of seconds to loosen it enough to drop the post.