As a weight weenie sort, on my off-topic bikes I've sometimes trimmed the
> posts to slightly less than 80mm insertion length and never had any
> problems. I'd read somewhere years ago that 2 1/2" is just sufficient. No
t
> that that means a lot of course. I'd think the post itself would be fine
if
> it's reasonably thick walled, but I might be concerned about the seat tub
e
> in this instance. It's definitely not as safety critical as a stem in any
> event. Anyone other weight weenies who've trimmed posts?
Kurt Sperry Bellingham WA
>
> I recently bought the Haral frame on eBay made of Excel CSK tubing which
> has a carbon sleeve inside a thin-walled steel tube. This presents a prob
lem
> with what sort of seatpost to use. The carbon sleeve starts approximately
80
> mm below the top of the seatlug. A 26.8 post will go in only that far, so
> the inner diameter of the carbon layer is smaller, perhaps 26.2.
>
> The seller says the post which came with the frame, which he hasn't found
> yet, was an American Classic 27.4 mm cut short to fit into the seattube
> section above the carbon sleeve. But it isn't clear whether this was
> original. Also not clear what post the frame manufacturer recommended. I
> could buy a 27.4 Kalloy Laprade and cut it to fit, but is 80 mm of
> seatpost insertion adequate? The frame is 55.5 to 56 cm ctc which is at
> the tall end of my range, so I'll probably have only about 50 mm of post
> exposed above the seatlug (not counting the post head). Does 80 mm insert
ion
> with 50 mm exposed sound safe? Does the thin wall of the steel tube incre
ase
> the risk of the small insertion? Someone recently mentioned a very short
> Campy Record post from the early 70's. How long was that post and what wo
uld
> its typical insertion length have been?
>
> I suppose I could use a post which fits inside the carbon sleeve and shim
> the section at the top of the seattube. Will any standard shim work for a
> 27.4/26.2 diameter?
>
> Regards,
>
> Jerry Moos
>
>
>
>
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