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Phil H
Jul 10, 2012, 7:11:19 PM7/10/12
to
I have a problem with my seat post. (Stop sniggering up the back.)
Basically, no matter how much I tighten the clamp, the seat will
rotate from time to time - usually when I look over my shoulder, or to
the side - and every time that happens, it slips down slightly. After
a few km I have to stop and reset the seat height.
Thus far I've tried cleaning the grease off the post, and tightening
the clamp as far as it will go, to no avail.
Any suggestions as to how I might fix this?
-- Phil
Basically, no matter how much I tighten the clamp, the seat will
rotate from time to time - usually when I look over my shoulder, or to
the side - and every time that happens, it slips down slightly. After
a few km I have to stop and reset the seat height.
Thus far I've tried cleaning the grease off the post, and tightening
the clamp as far as it will go, to no avail.
Any suggestions as to how I might fix this?
-- Phil
thefathippy
Jul 10, 2012, 10:53:57 PM7/10/12
to
On Wednesday, July 11, 2012 9:11:19 AM UTC+10, Phil H wrote:
> I have a problem with my seat post. (Stop sniggering up the back.)
>
> Basically, no matter how much I tighten the clamp, the seat will
> rotate from time to time - usually when I look over my shoulder, or to
> the side - and every time that happens, it slips down slightly. After
> a few km I have to stop and reset the seat height.
>
> Thus far I've tried cleaning the grease off the post, and tightening
> I have a problem with my seat post. (Stop sniggering up the back.)
>
> Basically, no matter how much I tighten the clamp, the seat will
> rotate from time to time - usually when I look over my shoulder, or to
> the side - and every time that happens, it slips down slightly. After
> a few km I have to stop and reset the seat height.
>
> the clamp as far as it will go, to no avail.
>
> Any suggestions as to how I might fix this?
>
>
> -- Phil
Bikes with carbon frames are supposed to use special grease, which has "bits" in it. I understood the bits are stop slippage. Maybe that would help? Maybe you have the wrong size post or clamp, or they're just worn? Beer can shim?
>
> Any suggestions as to how I might fix this?
>
>
> -- Phil
I don't really know, though, just clutching at straws. :^)
Tony F
Phil H
Jul 10, 2012, 11:41:18 PM7/10/12
to
On Jul 11, 12:53 pm, thefathippy <thefathi...@gmail.com> wrote:
> Bikes with carbon frames are supposed to use special grease, which has "bits" in it. I understood the bits are stop slippage. Maybe that would help? Maybe you have the wrong size post or clamp, or they're just worn? Beer can shim?
It's a newish Giant Suede with an alloy frame. All the components look
> Bikes with carbon frames are supposed to use special grease, which has "bits" in it. I understood the bits are stop slippage. Maybe that would help? Maybe you have the wrong size post or clamp, or they're just worn? Beer can shim?
like they're the right size.
> I don't really know, though, just clutching at straws. :^)
-- Phil
Tomasso
Jul 11, 2012, 1:15:38 AM7/11/12
to
Phil H wrote:
> On Jul 11, 12:53 pm, thefathippy <thefathi...@gmail.com> wrote:
>
>> Bikes with carbon frames are supposed to use special grease, which
>> has "bits" in it. I understood the bits are stop slippage. Maybe
>> that would help? Maybe you have the wrong size post or clamp, or
>> they're just worn? Beer can shim?
>
> It's a newish Giant Suede with an alloy frame. All the components look
> like they're the right size.
I used a "beer can" shim one one frame. Actually diet Pepsi can (scrounged from a bin somewhere).
> On Jul 11, 12:53 pm, thefathippy <thefathi...@gmail.com> wrote:
>
>> Bikes with carbon frames are supposed to use special grease, which
>> has "bits" in it. I understood the bits are stop slippage. Maybe
>> that would help? Maybe you have the wrong size post or clamp, or
>> they're just worn? Beer can shim?
>
> It's a newish Giant Suede with an alloy frame. All the components look
> like they're the right size.
Tom.
Dr Sir John Howard, AC, WSCMoF
Jul 11, 2012, 1:54:00 AM7/11/12
to
To fix it, cut little vertical groves into the post, if it's metal so that they
look like this -
||||||||||||||||||
all around that part of the post where you normally attach the clamp.
You may also need to replace the clamp.
This is the same idea as crimped clamps -
http://toolmonger.com/wp-content/uploads/2010/02/oetikertoolandclamps72-450.jpg
that image doesn't illustrate exactly what I mean but I think we've all seem the
ones with vertical crimps all around them.
If you can find a crimped clamp, all the better. Use that but cut fewer groves
into your post and try and make it so they line up for better grip.
--
http://www.youtube.com/watch?v=_ipvdBnU8F8
- KRudd at his finest.
"The Labour Party is corrupt beyond redemption!"
- Labour hasbeen Mark Latham in a moment of honest clarity.
"This is the recession we had to have!"
- Paul Keating explaining why he gave Australia another Labour recession.
"Silly old bugger!"
- Well known ACTU pisspot and sometime Labour prime minister Bob Hawke
responding to a pensioner who dared ask for more.
"By 1990, no child will live in poverty"
- Bob Hawke again, desperate to win another election.
"A billion trees ..."
- Borke, pissed as a newt again.
"Well may we say 'God save the Queen' because nothing will save the governor
general!"
- Egotistical shithead and pompous fuckwit E.G. Whitlam whining about his
appointee for Governor General John Kerr.
"SHUT THE FUCK UP YOU DUMB CUNT!"
- FlangesBum on learning the truth about Labour's economic capabilities.
"I don't care what you fuckers think!"
- KRudd the KRude Rat at his finest again.
"We'll just change it all when we get in."
- Garrett the carrott
"There will be no carbon tax."
- Juliar Dullard
John Henderson
Jul 11, 2012, 4:16:52 PM7/11/12
to
clamp". Like this:
http://clee-cycles.co.uk/esite/P3103/product
John
Rob
Jul 12, 2012, 1:45:57 AM7/12/12
to
On 11/07/2012 3:54 PM, Dr Sir John Howard, AC, WSCMoF wrote:
> Phil H wrote:
>> I have a problem with my seat post. (Stop sniggering up the back.)
>>
>> Basically, no matter how much I tighten the clamp, the seat will
>> rotate from time to time - usually when I look over my shoulder, or to
>> the side - and every time that happens, it slips down slightly. After
>> a few km I have to stop and reset the seat height.
>>
>> Thus far I've tried cleaning the grease off the post, and tightening
>> the clamp as far as it will go, to no avail.
>>
>> Any suggestions as to how I might fix this?
>
> I had that problem once too. It's caused by overtightening the seat clamp.
>
> To fix it, cut little vertical groves into the post, if it's metal so
> that they look like this -
>
> ||||||||||||||||||
>
> all around that part of the post where you normally attach the clamp.
>
> You may also need to replace the clamp.
>
> This is the same idea as crimped clamps -
>
> http://toolmonger.com/wp-content/uploads/2010/02/oetikertoolandclamps72-450.jpg
>
>
> that image doesn't illustrate exactly what I mean but I think we've all
> seem the ones with vertical crimps all around them.
>
> If you can find a crimped clamp, all the better. Use that but cut fewer
> groves into your post and try and make it so they line up for better grip.
>
Those Knipex clamps don't work on seat posts.
> Phil H wrote:
>> I have a problem with my seat post. (Stop sniggering up the back.)
>>
>> Basically, no matter how much I tighten the clamp, the seat will
>> rotate from time to time - usually when I look over my shoulder, or to
>> the side - and every time that happens, it slips down slightly. After
>> a few km I have to stop and reset the seat height.
>>
>> Thus far I've tried cleaning the grease off the post, and tightening
>> the clamp as far as it will go, to no avail.
>>
>> Any suggestions as to how I might fix this?
>
> I had that problem once too. It's caused by overtightening the seat clamp.
>
> To fix it, cut little vertical groves into the post, if it's metal so
> that they look like this -
>
> ||||||||||||||||||
>
> all around that part of the post where you normally attach the clamp.
>
> You may also need to replace the clamp.
>
> This is the same idea as crimped clamps -
>
> http://toolmonger.com/wp-content/uploads/2010/02/oetikertoolandclamps72-450.jpg
>
>
> that image doesn't illustrate exactly what I mean but I think we've all
> seem the ones with vertical crimps all around them.
>
> If you can find a crimped clamp, all the better. Use that but cut fewer
> groves into your post and try and make it so they line up for better grip.
>
Rob
Jul 12, 2012, 1:49:36 AM7/12/12
to
post in the tube. (unsure the exact tube / post sizes off hand) but
even these come in 0.5 mm increments)
Beer cans will shim the post but as now you are not making proper
contact when its tightened.
Was the seat and post taken from another frame by chance? hence being
the incorrect size.
Rob
Jul 12, 2012, 1:51:49 AM7/12/12
to
bolt :)
Phil H
Jul 15, 2012, 7:07:28 PM7/15/12
to
Thanks for the suggestions!
As it turns out, the problem was quite simple: the clamp wasn't tight
enough. However, I had been pressing the QR lever down as hard as I
could, which is pretty damned hard. Close examination of the
disassembled clamp showed the following: the lever has a cam on the
end, which presses onto a small brass shoe, which in turn presses on
the actual clamp to close it. The brass is obviously there to avoid
aluminium-on-aluminium contact, but it was seriously out of shape, and
contact was poor. This poor contact had roughed up the cam and the
resulting friction made it very hard to close. The solution was to
sand the brass and cam smooth, apply some grease and put it back
together. It's now much easier to close, and I can tighten the bugger
up until the seat doesn't move.
-- Phil
As it turns out, the problem was quite simple: the clamp wasn't tight
enough. However, I had been pressing the QR lever down as hard as I
could, which is pretty damned hard. Close examination of the
disassembled clamp showed the following: the lever has a cam on the
end, which presses onto a small brass shoe, which in turn presses on
the actual clamp to close it. The brass is obviously there to avoid
aluminium-on-aluminium contact, but it was seriously out of shape, and
contact was poor. This poor contact had roughed up the cam and the
resulting friction made it very hard to close. The solution was to
sand the brass and cam smooth, apply some grease and put it back
together. It's now much easier to close, and I can tighten the bugger
up until the seat doesn't move.
-- Phil
Tomasso
Jul 16, 2012, 8:03:11 PM7/16/12
to
"Phil H" <phil_h...@yahoo.com.au> wrote in message
news:41719845-2cfa-4528...@s6g2000pbi.googlegroups.com...
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