Wobbly/slipping seatpost

[marcusjb]

Before I speak with Condor tomorrow, I was wondering if anyone can think of any reason why the below would happen?

I've just built up a Condor Fratello frameset recently, and have had a problem with the seatpost slipping down.  I suffered terribly on the Elenith as the damned thing would slip down a few mm over time, so my knees were destroyed by the end of it.  I thought I'd got it (by tightening the seat collar up using the force of several gorillas).  But no, just been out for 70km with some mates, and it slipped again.

You can actually see a small gap around the post when inserted - and before tightening, the seatpost can be moved fore and aft with a little wobble.

I was told the Fratello is a 27.2 seatpost, and that's what's in it - I've tried another 27.2 post from another bike and the same - wobbly before tightening.

There's nothing obvious I am missing is there? A seatpost shouldn't wobble in the seat-tube - even before tightening?

I bought it as frameset only, and the seat-tube has clearly been cleaned out of paint overspray as part of the prep they've done - I am guessing this is where the process has gone wrong?

I hope this isn't going to turn into a tricky one with them - the pain is obviously I have built up the bike, spent a lot of time getting it how I want etc. - if this frame is wrong (and I think it is), I will have to work on convinving them to be swapping the gear over onto a replacement frame etc. 

[oncemore]

If TWO 27.2s are too small than a fair bet that the seat tube is too big. So either Condor remedy or you use a shim and a smaller post (sounds as if too near a fit to use a shim with a 27.2). While a shim will be "for" a true 27.2, might give sufficient margin to hold say a 26.8?

just thoughts.

[Luke]

Have you tried a different seat clamp?

[LittleWheelsandBig]

There are some 27.4 mm seatposts out there.

[marcusjb]

If TWO 27.2s are too small than a fair bet that the seat tube is too big. So either Condor remedy or you use a shim and a smaller post (sounds as if too near a fit to use a shim with a 27.2). While a shim will be "for" a true 27.2, might give sufficient margin to hold say a 26.8?

just thoughts.

]

It probably doesn't even need a shim to be honest.  One of my friends suggested just a wrap of insulation tape around the seat post and that should hold it.

But, if a frame is sold as having a 27.2 seat tube - surely it should be able to take a 27.2 seatpost and hold it into place!

The seatpost shouldn't be able to be wobbled within the tube I'd have thought!

Have you tried a different seat clamp?

Yes and no - I bought a replacement seat clamp when I popped into Condor yesterday.  I had to tighten the heck out of the clamp on the Elenith to try and keep the seat post from slipping, so I wanted to replace it.  Said to the chap in the shop what frame it was for, bought it, and it's too small.  Condor have gone from being very good to not not my best friends at the moment!

[Steve Kish]

One of my friends suggested just a wrap of insulation tape around the seat post and that should hold it.

Won't do it, as it's vinyl and flexible.  If you're looking for a shim, try a piece of a soft drinks can in aluminium, like Coke.

However, if it takes an external clamp rather than a braze-on, the real answer may be one of these:-

eXotic 6061 T6 Non Slip Double Seat Clamp 31.8 27.2 Pat | eBay UK

I use one on both my non-carbon all-aluminium frames and they are bulletproof!

[marcusjb]

All (nearly) sorted.

Spoke to Condor first thing, and they said to pop by.  I was in town this afternoon anyway, so took the Fratello in (was I at all nervous leaving a £3K bike locked up in Mayfair for a couple of hours?  Only a little!).

So popped into Condor, they measured my seatpost with a set of calipers - 27.23mm - bang on.

Measured the hole in the seat-tube - 27.38mm - not so bang on!

Tried one of their posts in the hole - still wobbled. 

Basically, the shim that is inserted into the seat-tube is not the right size - they've not seen this before (they did have a batch where the shim was too short a couple of years ago - leading to some failures around the seat cluster).  So, they will replace the frame for me, as there's nothing that can be done with it.  They'll also swap over all the components for me as well - so that's all good.

Only challenge is that they've sold all of their first batch of 2011 frames - so it'll be a month or so before this happens.

So, what to do in the meantime?  They took the thinnest shim they had, and used half of it - and the seat post feels like it isn't going anywhere.  The mechanic said it wasn't an elegant solution - but it would hold together for a month and keep me riding etc.

They were very apologetic, and didn't quibble about any of it - they'd measured the hole, it was wrong, therefore, it needed to be replaced.

Good service and hopefully resolution to the problem (though I may sue them for the distress caused to my knees on the Elenith!).

[Blodwyn Pig]

jubilee clip will sort that out, or an aditional clamp of some sort, to stop slippage.

[hubner]

Does the frame have an oversized seat tube, and a shim inside the seat tube so it can use a 27.2mm seatpost ?

[marcusjb]

Does the frame have an oversized seat tube, and a shim inside the seat tube so it can use a 27.2mm seatpost ?

It's not a removable shim, but something fitted at manufacture. You can just about feel the end of it with your finger. For whatever reason, the one in my frame is not the right size.

But, all credit to them, they were quick to suggest they'd replace the frame and swap all my gear for me. So now just have to get out more and enjoy the frame more (without having to put the saddle back up every few km!)

[Canardly]

Someone said I should hang on to my fluted seat posts. Is this true?

[Sergeant Pluck]

So, they will replace the frame for me, as there's nothing that can be done with it. 
They were very apologetic, and didn't quibble about any of it - they'd measured the hole, it was wrong, therefore, it needed to be replaced.

Rightly so, glad to hear this. In your position that is the only outcome that I'd be happy with.

[Sergeant Pluck]

jubilee clip will sort that out, or an aditional clamp of some sort, to stop slippage.

Nonsense.

Jubilee clip on a brand new frame? Not I.

[phil d]

jubilee clip will sort that out, or an aditional clamp of some sort, to stop slippage.

Nonsense.

Jubilee clip on a brand new frame? Not I.

I wonder whether YS was suggesting an jubilee clip on the post to stop it slipping down (won't stop it twisting, though).  As I have to take the seatpost out of my bike when putting it in the car, I have a jubilee clip on the post so it always goes back in to the exact depth required for comfort.

[Gog yn y De]

Mig welder should sort it