Where to clamp bike to work on it?

I've got a Lemond Alpe D'Huez that I’m growing increasingly fond of.
One thing I’ve noticed is at higher tire pressure, road vibration is a
bit much on my rear. 90ish feels a bit slow. 100-110 feels good.
120 feels real good on perfectly smooth, brand new pavement but when I
hit cracks in the pavement it’s not the most comfortable thing in the
world. One of the things that I think could help with this a tad is a
carbon post. My concern then is where to clamp the bike to work on
it? I’m afraid putting enough pressure to properly secure the bike on
a carbon post would crack it. The aluminum front triangle of the
frame is also insanely thin – flicking it with your finger nail feels
like you could dent it. I’d be afraid to clamp to this as well.
Ideas?

I’m sure some of you will tell me to ride @ 90psi, it’s plenty and
absorbs the road better. Thing is, most of the roads I ride on are
really, really smooth and the higher pressures just feel faster (not
to mention they seem to reflect a slightly faster overall average at
the end of my ride, for the same course with the same perceived energy
output). I can actually see the shape of the tire deform a bit @ 90,
at 110 it seems to pretty much hold its shape. There’s a chance I’ll
find I’m no faster (nor do I feel any faster) @ 120 than at 105-110,
but I won’t know until I can try it without lifting off the saddle for
every crack in the road (few and far between as they may be).

Input appreciated.

On Aug 7, 12:48 pm, " wrote:
I've got a Lemond Alpe D'Huez that I’m growing increasingly fond of.
One thing I’ve noticed is at higher tire pressure, road vibration is a
bit much on my rear. 90ish feels a bit slow. 100-110 feels good.
120 feels real good on perfectly smooth, brand new pavement but when I
hit cracks in the pavement it’s not the most comfortable thing in the
world. One of the things that I think could help with this a tad is a
carbon post. My concern then is where to clamp the bike to work on
it? I’m afraid putting enough pressure to properly secure the bike on
a carbon post would crack it. The aluminum front triangle of the
frame is also insanely thin – flicking it with your finger nail feels
like you could dent it. I’d be afraid to clamp to this as well.
Ideas?

I’m sure some of you will tell me to ride @ 90psi, it’s plenty and
absorbs the road better. Thing is, most of the roads I ride on are
really, really smooth and the higher pressures just feel faster (not
to mention they seem to reflect a slightly faster overall average at
the end of my ride, for the same course with the same perceived energy
output). I can actually see the shape of the tire deform a bit @ 90,
at 110 it seems to pretty much hold its shape. There’s a chance I’ll
find I’m no faster (nor do I feel any faster) @ 120 than at 105-110,
but I won’t know until I can try it without lifting off the saddle for
every crack in the road (few and far between as they may be).

Input appreciated.

use the old al post to clamp your bike

wrote:
use the old al post to clamp your bike
^^^^^^^^^^^^^^^^^^^
Or clamp to the seat tube with the carbon seatpost inside. If you grab just
below the seatclamp, you don't have to tighten the clamp much, since it
can't slide down past the clamp.

On Aug 7, 1:48*pm, " wrote:
*One of the things that I think could help with this a tad is a
carbon post.

You thought wrong. It won't help do anything but lighten your wallet
and maybe your bike by a couple grams or not. Some aluminum posts are
awful light. Problem solved. Keep clamping by the post.

I’m sure some of you will tell me to ride @ 90psi, it’s plenty and
absorbs the road better. *Thing is, most of the roads I ride on are
really, really smooth and the higher pressures just feel faster (not
to mention they seem to reflect a slightly faster overall average at
the end of my ride, for the same course with the same perceived energy
output). *I can actually see the shape of the tire deform a bit @ 90,
at 110 it seems to pretty much hold its shape. *There’s a chance I’ll
find I’m no faster (nor do I feel any faster) @ 120 than at 105-110,
but I won’t know until I can try it without lifting off the saddle for
every crack in the road (few and far between as they may be).


The tire deforming is the tire doing what it's supposed to do--acting
as suspension. You might want to try a high quality 25mm tire at 90psi
or play with the pressure in your current set some more. You can run
less pressure in the front. Higher pressure doesn't always mean
faster--being comfortable and rolling over stuff instead of fearing
every crack is a good thing.

On Aug 7, 3:39*pm, "Leo Lichtman" wrote:
wrote:

use the old al post to clamp your bike
^^^^^^^^^^^^^^^^^^^
Or clamp to the seat tube with the carbon seatpost inside. *If you grab just
below the seatclamp, you don't have to tighten the clamp much, since it
can't slide down past the clamp.

Both good ideas, although I don't really like the idea of having to
swap a seat post to adjust a bike. I'd be curious to hear from shop
owners where they clamp thin or carbon framed bikes with carbon posts,
and how hard they clamp down. It has to be hard enough to keep the
bike from swinging around when you pedal, no?

On 2008-08-07, landotter wrote:
On Aug 7, 1:48?pm, " wrote:

I?m sure some of you will tell me to ride @ 90psi, it?s plenty and
absorbs the road better. ?Thing is, most of the roads I ride on are
really, really smooth and the higher pressures just feel faster (not
to mention they seem to reflect a slightly faster overall average at
the end of my ride, for the same course with the same perceived energy
output). ?I can actually see the shape of the tire deform a bit @ 90,
at 110 it seems to pretty much hold its shape. ?There?s a chance I?ll
find I?m no faster (nor do I feel any faster) @ 120 than at 105-110,
but I won?t know until I can try it without lifting off the saddle for
every crack in the road (few and far between as they may be).


The tire deforming is the tire doing what it's supposed to do--acting
as suspension. You might want to try a high quality 25mm tire at 90psi
or play with the pressure in your current set some more. You can run
less pressure in the front. Higher pressure doesn't always mean
faster--being comfortable and rolling over stuff instead of fearing
every crack is a good thing.

I'll second that. I ride 25s (Continental Ultra Race kevlar bead), at
roughly 85 front, 95 rear (I weigh 165ish). The comfort is light-years
ahead of what is was back when I rode at 120 for both tires. Newly repaved
roads are still smooth as glass, and the rest are plenty tolerable.

--

Kristian Zoerhoff

wrote:

I also have an Al frame and thought a carbon seatpost the way to go. I
got a USA Alien and found no difference in the ride AT ALL. I think the
idea of carbon being softer is when you have carbon seat and chain stays
which may absorb some vibration, but the straight tube transmitted all
the vibration just like the old Al seatpost did.

I clamp to the seatpost anyway and so far have had no problems. If I had
to do it again, I"d not spend the money on the plastic post.

"Paul Cassel" wrote in message
. ..
wrote:

I also have an Al frame and thought a carbon seatpost the way to go. I got
a USA Alien and found no difference in the ride AT ALL. I think the idea
of carbon being softer is when you have carbon seat and chain stays which
may absorb some vibration, but the straight tube transmitted all the
vibration just like the old Al seatpost did.

I don't think it matters that the carbon seatpost is straight or not. What
does matter is that there's simply not enough of it (carbon) to make a
difference. Unless it was long enough to flex significantly (probably not
the case), I don't think it matters much what the seatpost is made of, aside
from weight (and even then, there are some pretty light aluminum seatposts).

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

"Mike Jacoubowsky" wrote: I don't think it matters that the carbon
seatpost is straight or not. (clip)
^^^^^^^^^^^^^^^^^^^
I think that what Paul meant to convey is that a beam in compression is not
going to offer any cushioning effect. I will add that a carbon fiber seat
post with a bend in it might absorb some road shock before it breaks.

landotter wrote:
On Aug 7, 1:48�pm, " wrote:
�One of the things that I think could help with this a tad is a
carbon post.

You thought wrong.

no, he thought right. carbon does attenuate vibration. it may not be
enough for /you/ to care about, but it's real.


It won't help do anything but lighten your wallet
and maybe your bike by a couple grams or not. Some aluminum posts are
awful light. Problem solved. Keep clamping by the post.

I�m sure some of you will tell me to ride @ 90psi, it�s plenty and
absorbs the road better. �Thing is, most of the roads I ride on are
really, really smooth and the higher pressures just feel faster (not
to mention they seem to reflect a slightly faster overall average at
the end of my ride, for the same course with the same perceived energy
output). �I can actually see the shape of the tire deform a bit @ 90,
at 110 it seems to pretty much hold its shape. �There�s a chance I�ll
find I�m no faster (nor do I feel any faster) @ 120 than at 105-110,
but I won�t know until I can try it without lifting off the saddle for
every crack in the road (few and far between as they may be).


The tire deforming is the tire doing what it's supposed to do--acting
as suspension. You might want to try a high quality 25mm tire at 90psi
or play with the pressure in your current set some more. You can run
less pressure in the front. Higher pressure doesn't always mean
faster--being comfortable and rolling over stuff instead of fearing
every crack is a good thing.