Seat Post Slipping

[BigTone0777]

I've had trouble in the past with correct size seatposts slipping - it was due to 2 things:



1. being fat

2. crap seatpost clamp



Didn't lose weight but did change the clamp - problem solved!

Buy a good quality chunky clamp with a large steel bolt

I'm fat too but already bought a decent quality clamp so hopefully a new post will sort it coz I ain't loosing weight in a hurry lol

 

[BigTone0777]

Well, a trip to the LBS showed up 2 things.

1) I am a fool lol (didn't realise the size is stamped on the seat post)

2) The correct size post is already fitted

I have now ordered a digital vernier so I can accurately measure the post to see if it's poorly manufactured and a little undersize (it is a Carrera afterall) and to check to see that the seat tube is the correct size and not poorly manufactured and slightly oversize (it is a Carrera afterall ha ha ha). I am now really stumped at what the problem can be and am getting slightly fed up with having to raise my seat when prompted by the pain in my knees that I am sitting too low again!

 

[smokeysmoo]

1) I am a fool lol (didn't realise the size is stamped on the seat post)

No you're not BT, it's not always stamped on so don't worry about it

 

[Angelfishsolo]

I take it the LBS offered no opinions then?

Well, a trip to the LBS showed up 2 things.

1) I am a fool lol (didn't realise the size is stamped on the seat post)

2) The correct size post is already fitted

I have now ordered a digital vernier so I can accurately measure the post to see if it's poorly manufactured and a little undersize (it is a Carrera afterall) and to check to see that the seat tube is the correct size and not poorly manufactured and slightly oversize (it is a Carrera afterall ha ha ha). I am now really stumped at what the problem can be and am getting slightly fed up with having to raise my seat when prompted by the pain in my knees that I am sitting too low again!

 

[e-rider]

a new seatpost would have cost less that a digital vernier! as changing the frame isn't really a good option, a new seatpost and clamp are your only options.

what size post are you using?

 

[BigTone0777]

The only advice was to rough it up with some emery cloth and use a bit of copper slip to try to take up the gap. Gonna give it a measure when my vernier comes then be a pain in the arse at the LBS measuring post's to compare measurements lol. Oh the other thing is the slot down the back of the seat tube has a good gap so could it be that my decent quality clamp isn't clamping quite tight enough???

 

[smokeysmoo]

Could be the clamp, a decent clamp is a sound investment even if you end swopping the post.

 

[e-rider]

The only advice was to rough it up with some emery cloth and use a bit of copper slip to try to take up the gap. Gonna give it a measure when my vernier comes then be a pain in the arse at the LBS measuring post's to compare measurements lol. Oh the other thing is the slot down the back of the seat tube has a good gap so could it be that my decent quality clamp isn't clamping quite tight enough???

I doubt if the new clamp is causing the problem and there should be a visible slot in the frame even with the clamp done tight.

So what size does your post have stamped on it?

 

[BigTone0777]

The post is 27.2mm. I have just taken some pics to show you guy's and see what you think. Just in from a wet ride home from work so please excuse the dirt!

 

[e-rider]

The post is 27.2mm. I have just taken some pics to show you guy's and see what you think. Just in from a wet ride home from work so please excuse the dirt!

I can now end your misery - YOU ARE USING A Q/R CLAMP!!!

They apply no way near as much force as a decent clamp with a steel bolt.

You should have mentioned this in your first post!

Q/R clamps are ok for weight weenies but not the larger build rider.

 

[smokeysmoo]

I can now end your misery - YOU ARE USING A Q/R CLAMP!!!

+1, get yourself a decent bolted clamp and you should be laughing

 

[Zoiders]

I wouldn't say they were all for weight weenies, what I would say is that not all QR clamps are made equal.

If you look at yours you will see the cam moves against a black PTFE/Delrin plastic washer, these can wear or deform over time if the clamp is over tightened or left done up for too long.

A new good quality QR clamp and all will be well.

 

[smokeysmoo]

A new good quality QR clamp and all will be well.

If you need to remove your seatpost regularly I'd agree with the above, (assuming the old worn is worn), but if seatpost removal is not a priority, then a bolted clamp will still tighten more than a QR, and offer far more security from pikeys

 

[BigTone0777]

I can now end your misery - YOU ARE USING A Q/R CLAMP!!!

A "proper" clamp it is then ha ha ha!


Thanks for the advice!

 

[BigTone0777]

New clamp ordered! Will let you know how it go's when it arrives. Thanks for all your replies and advice!

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