Seatpost Clamp

Well, this is probably a pretty silly question - but here goes anyway...

I want to make sure I know the correct way to fit my seatpost clamp
(since, although the clamp is tight - I can't twist the seat - my
seatpost gradually descends a couple mm per day)...

I have an aluminum frame Specialized Sirrus Pro. The seatpost clamp is
a slotted aluminum ring, stamped 32, with a ridge around the inside on
what I take to be the top.

I presume the clamp fits over the seat tube, with the ridge serving as a
stop to prevent the clamp from dropping down too far. In other words,
the ridge sits "above" the seat tube and doesn't squeeze the seat tube
per se (wthe larger-diameter lower part of the clamp does squeeze the
seat tube).

Do I have that right?

Thanks!
--
Rob Lindauer - Please change "att" to "sbc" for my real email address

"Rob Lindauer" wrote in message
...
Well, this is probably a pretty silly question - but here goes anyway...

I want to make sure I know the correct way to fit my seatpost clamp
(since, although the clamp is tight - I can't twist the seat - my seatpost
gradually descends a couple mm per day)...

I have an aluminum frame Specialized Sirrus Pro. The seatpost clamp is a
slotted aluminum ring, stamped 32, with a ridge around the inside on what
I take to be the top.

I presume the clamp fits over the seat tube, with the ridge serving as a
stop to prevent the clamp from dropping down too far. In other words, the
ridge sits "above" the seat tube and doesn't squeeze the seat tube per se
(wthe larger-diameter lower part of the clamp does squeeze the seat tube).

Do I have that right?

Yes you have it correct. I would think that your seatpost is carbon fiber.
This stuff is too slick for this sort of locking mechanism. I have the same
problem on my Time VX. You can solve the problem by buying a Shimano,
Thompson or some other aluminum seatpost which will probably be lighter and
won't slide down after proper tightening.

Tom Kunich wrote:


Yes you have it correct. I would think that your seatpost is carbon
fiber. This stuff is too slick for this sort of locking mechanism. I
have the same problem on my Time VX. You can solve the problem by buying
a Shimano, Thompson or some other aluminum seatpost which will probably
be lighter and won't slide down after proper tightening.


Thanks, Tom. It's an older, less sophisticated, with aluminum seatpost
and frame. It would appear I just need to snug the clamp a bit more
(but I'll also check with the shop or manufacturer that the clamp I have
is indeed the right size). Thanks again, Rob L


--
Rob Lindauer - Please change "att" to "sbc" for my real email address

"Rob Lindauer" wrote in message
...
Tom Kunich wrote:


Yes you have it correct. I would think that your seatpost is carbon
fiber. This stuff is too slick for this sort of locking mechanism. I have
the same problem on my Time VX. You can solve the problem by buying a
Shimano, Thompson or some other aluminum seatpost which will probably be
lighter and won't slide down after proper tightening.

Thanks, Tom. It's an older, less sophisticated, with aluminum seatpost
and frame. It would appear I just need to snug the clamp a bit more (but
I'll also check with the shop or manufacturer that the clamp I have is
indeed the right size). Thanks again, Rob L

Once in awhile you discover that the person who installed the seatpost
greased it. Simply cleaning the grease off and reinstallation in a cleaned
out seattube would cure that problem.

In article ,
Rob Lindauer wrote:

Well, this is probably a pretty silly question - but here goes anyway...

I want to make sure I know the correct way to fit my seatpost clamp
(since, although the clamp is tight - I can't twist the seat - my
seatpost gradually descends a couple mm per day)...

I have an aluminum frame Specialized Sirrus Pro. The seatpost clamp is
a slotted aluminum ring, stamped 32, with a ridge around the inside on
what I take to be the top.

I presume the clamp fits over the seat tube, with the ridge serving as a
stop to prevent the clamp from dropping down too far. In other words,
the ridge sits "above" the seat tube and doesn't squeeze the seat tube
per se (wthe larger-diameter lower part of the clamp does squeeze the
seat tube).

Do I have that right?

Yes. One refinement is to rotate the clamp so that the
slot on the clamp is half a revolution away from the
slot in the seat tube. This almost certainly will _not_
fix your current difficulty, but is worth doing.

--
Michael Press

On Mon, 02 Jun 2008 19:03:05 -0400, Rob Lindauer
may have said:

Well, this is probably a pretty silly question - but here goes anyway...

I want to make sure I know the correct way to fit my seatpost clamp
(since, although the clamp is tight - I can't twist the seat - my
seatpost gradually descends a couple mm per day)...

I have an aluminum frame Specialized Sirrus Pro. The seatpost clamp is
a slotted aluminum ring, stamped 32, with a ridge around the inside on
what I take to be the top.

I presume the clamp fits over the seat tube, with the ridge serving as a
stop to prevent the clamp from dropping down too far. In other words,
the ridge sits "above" the seat tube and doesn't squeeze the seat tube
per se (wthe larger-diameter lower part of the clamp does squeeze the
seat tube).

Do I have that right?

Yes. Additionally, the seatpost clamp may need just a tiny amount of
grease between it and the frame in order to achieve a tight grip.


--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

On Tue, 03 Jun 2008 07:33:59 -0700, Michael Press
may have said:

In article ,
Rob Lindauer wrote:

Well, this is probably a pretty silly question - but here goes anyway...

I want to make sure I know the correct way to fit my seatpost clamp
(since, although the clamp is tight - I can't twist the seat - my
seatpost gradually descends a couple mm per day)...

I have an aluminum frame Specialized Sirrus Pro. The seatpost clamp is
a slotted aluminum ring, stamped 32, with a ridge around the inside on
what I take to be the top.

I presume the clamp fits over the seat tube, with the ridge serving as a
stop to prevent the clamp from dropping down too far. In other words,
the ridge sits "above" the seat tube and doesn't squeeze the seat tube
per se (wthe larger-diameter lower part of the clamp does squeeze the
seat tube).

Do I have that right?

Yes. One refinement is to rotate the clamp so that the
slot on the clamp is half a revolution away from the
slot in the seat tube. This almost certainly will _not_
fix your current difficulty, but is worth doing.

Grease the interface between the two when using this technique; this
method minimizes the chance that the frame's tube will be distorted by
the clamp, but it also can reduce the effectiveness of the clamp if
the surfaces aren't lubricated.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

My thanks to all for your replies / assistance. -RL

--
Rob Lindauer - Please change "att" to "sbc" for my real email address

On Jun 2, 5:03*pm, Rob Lindauer wrote:
Well, this is probably a pretty silly question - but here goes anyway...

I want to make sure I know the correct way to fit my seatpost clamp
(since, although the clamp is tight - I can't twist the seat - my
seatpost gradually descends a couple mm per day)...

I have an aluminum frame Specialized Sirrus Pro. *The seatpost clamp is
a slotted aluminum ring, stamped 32, with a ridge around the inside on
what I take to be the top.

I presume the clamp fits over the seat tube, with the ridge serving as a
stop to prevent the clamp from dropping down too far. *In other words,
the ridge sits "above" the seat tube and doesn't squeeze the seat tube
per se (wthe larger-diameter lower part of the clamp does squeeze the
seat tube).

Do I have that right?

Thanks!
--
Rob Lindauer - Please change "att" to "sbc" for my real email address

Yes and if the seatpost is aluminum, go to a good bike shop and have
the seatpost 'knurled' with a tool that adds ridges to thew post,
preventing it from slipping.