Internal seatpost clamp (Colnago) - height adjustment

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CreakyCrank
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Joined: Sun Nov 12, 2017 12:15 pm

Internal seatpost clamp (Colnago) - height adjustment

Postby CreakyCrank » Sat Dec 16, 2017 8:46 pm

As of this morning I'm a proud owner of a new Colnago C-RS racer.
It has what is called an internal seatpost clamp (with adjustment screw facing upwards).
How do I loosen the seatpost to adjust the seat height. My initial attempt at loosening the one visible bolt had no effect on loosening the seatpost (up until now I am only accustomed to the good old seat clamp).
Having spent top $$$ I am reluctant to use any force whatsoever (I have a bad history in this regard :oops: )

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A_P
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Location: Gold Coast

Re: Internal seatpost clamp (Colnago) - height adjustment

Postby A_P » Sat Dec 16, 2017 9:07 pm

likely that its a wedge, similar to quill headstem
loosen bolt a bit and push down to loosen wedge?
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open roader
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Location: Dueling Banjo Country, Otway fringes, Victoria

Re: Internal seatpost clamp (Colnago) - height adjustment

Postby open roader » Sun Dec 17, 2017 10:47 am

I've seen the Colnago Concept in the flesh. The C-RS has a similar seat clamping / tension system to the Concept.

From what I gather the bolt simply holds a triangular shaped wedge piece in place up against the seatpost tube ie the bolt forces the wedge down between the seat post tube and the frame lug/groove. Once you have sufficiently slackened off the bolt tension the wedge should be able to be slipped back towards the front of the frame ie. off and away from the seatpost tube surface.

Your brand new wedge may be simply jammed from shipping or overly zealous workshop construction or someone sitting on the saddle without the wedge being correctly tensioned ie it's slipped down and jammed.

I'd remove the bolt entirely then use something down the bolt hole of the wedge part only (as I suspect there is thread only in the frame lug - not in the wedge itself) in an attempt to lift the wedge out of it's lug/groove.
3rd class cycling is always better than 1st class walking

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CreakyCrank
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Re: Internal seatpost clamp (Colnago) - height adjustment

Postby CreakyCrank » Sun Dec 17, 2017 5:59 pm

Thanks for the advice.
I loosened the bolt totally and firmly wiggled and jiggled the seatpost until it freed itself.
I also invested in a torque wrench set so no more guessing required.

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open roader
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Location: Dueling Banjo Country, Otway fringes, Victoria

Re: Internal seatpost clamp (Colnago) - height adjustment

Postby open roader » Sun Dec 17, 2017 10:04 pm

CreakyCrank wrote:I also invested in a torque wrench set so no more guessing required.


Good move. I'd also invest in some carbon construction paste for the seat post - should assist to keep your actual seat post clamp torque well below 7.5Nm
3rd class cycling is always better than 1st class walking

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