john
It sounds like you need a next size larger seatpost. Ie go up 0.2 mm. I am
guessing you have issues with a slipping seatpost also?
There's nothing worse then a poor fitting seatpost. A lot of power and
force goes through that connection and you want a nice stiff connection (ie
very snug slip fit).
On a number of occasions through the years, I have went from 26.8 to a 27 or
27.2 to 27.4.. Sometimes the seat tube is almost there anyway, ie its
already a 27.3 or something, or not round? It takes a little bit of
patience and time to get a nice fit or a skilled mechanic. I usually ream a
tad, and flex ball hone, clean, test fit, repeat... And I fit to the
seatpost i will be using. Obviously you don't want to go over! You want a
nice sharp reamer, so you cut and don't "tear" the metal. My reamer is
somwhat poor so I flex hone (grind ball hone.. ) as well to smooth/polish
the tube surface even further so I don't get stress risers. My frames are
steel though.. aluminum probably just ream, but be really careful to go slow
(ie take just a tiny bit off, test, repeat..)
with above knowledge, Go to a bike shop they can help you out...
I know probably not what you want to hear since now you will probably need a
new seatpost. thomson's sure are nice....
On Thu, Apr 23, 2009 at 9:41 AM, Brian Johnson wrote:
> Hey all,
> I'm looking for a decent seatpost clamp that's compatible with a cable
> hanger for my cyclocross bike. (Salsa's nice looking clamps don't have
> enough space for a cable hanger. Boo.)
>
> Right now I've got a no-name/OEM thing on there and I'm convinced that it
> deforms when tightened and has caused some minor surface damage to my sweet
> sweet Thomson seatpost.
>
> From the marks on the post it appears that clamping forces are concentrated
> at the binder bolt and sort of pinching in the seat tube.
>
> It's also quite possible that I've overtightened the clamp-- I don't use a
> torque wrench but instead tighten only enough to prevent the seatpost from
> being easily twisted.
>
> Anyway-- any recommendations?
>
> * * *
> My father asks : "Do you live here or ride bikes?"
>
> http://liveorridebikes.blogspot.com
>
>
>
>
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--
jms, pe pdx, or
http://bikeeng.blogspot.com/