I'm building up a TT bike. I've got it all put together, but it's got a very conventional seatpost. Does anyone have any good data that would point to whether or not investing in a good aero seatpost would make any meaningful difference? I'm considering one of the Corima carbon posts, but I don't need to toss $125 if it's just a waste. On the other hand, my objective is to assemble the fastest bike I can and that's one area that remains to be addressed.
Thanks for any insights.
-- Bob C.
"Of course it hurts. The trick is not minding that it hurts." T. E. Lawrence (of Arabia)
Zog The Undeniable 27 February 2005 20:46:46 [ permanent link ]
psycholist wrote:> I'm building up a TT bike. I've got it all put together, but it's got a > very conventional seatpost. Does anyone have any good data that would point > to whether or not investing in a good aero seatpost would make any > meaningful difference? I'm considering one of the Corima carbon posts, but > I don't need to toss $125 if it's just a waste. On the other hand, my > objective is to assemble the fastest bike I can and that's one area that > remains to be addressed.
Mike Burrows, designer of Chris Boardman's Lotus Olympic bike, says they're worth it. Other people say the airflow is already so disturbed by the bars and your legs (you do cycle with your legs almost touching the top tube, don't you?) that the post makes no difference at all.
Still, it's a cheap upgrade if it frightens the opposition...
On Sun, 27 Feb 2005 12:08:43 -0600, dianne_1234 <dianne_1234@NOSPAMyahoo.com> wrote:
On Sun, 27 Feb 2005 11:24:15 -0500, "psycholist" <technico@wctel.net>>wrote:>
I'm building up a TT bike. I've got it all put together, but it's got a >>very conventional seatpost. Does anyone have any good data that would point >>to whether or not investing in a good aero seatpost would make any >>meaningful difference? I'm considering one of the Corima carbon posts, but >>I don't need to toss $125 if it's just a waste. On the other hand, my >>objective is to assemble the fastest bike I can and that's one area that >>remains to be addressed.>>
Do you know how (or if) Cobb handles the problem of spinning both the bicycle's wheels and getting the rider to pedal in wind-tunnel tests?
The wind-tunnel pictures that I've seen seem to show riders crouching motionless on bikes whose wheels aren't moving, which isn't a very good imitation of the real thing.
psycholist wrote:> I'm building up a TT bike. I've got it all put together, but it's> got a very conventional seatpost. Does anyone have any good data> that would point to whether or not investing in a good aero seatpost> would make any meaningful difference? I'm considering one of the> Corima carbon posts, but I don't need to toss $125 if it's just a> waste. On the other hand, my objective is to assemble the fastest> bike I can and that's one area that remains to be addressed.>
On Sun, 27 Feb 2005 11:46:34 -0800, "Dan" <Banquo_lives@yahoo.com> wrote:
<carlfogel@comcast.net> wrote in message>news:i6442112rmceitenq945408in7qjcru6sc@4ax.com...>> On Sun, 27 Feb 2005 12:08:43 -0600, dianne_1234>> <dianne_1234@NOSPAMyahoo.com> wrote:>>
On Sun, 27 Feb 2005 11:24:15 -0500, "psycholist" <technico@wctel.net>>> >wrote:>> >
I'm building up a TT bike. I've got it all put together, but it's got a>> >>very conventional seatpost. Does anyone have any good data that would>point>> >>to whether or not investing in a good aero seatpost would make any>> >>meaningful difference? I'm considering one of the Corima carbon posts,>but>> >>I don't need to toss $125 if it's just a waste. On the other hand, my>> >>objective is to assemble the fastest bike I can and that's one area that>> >>remains to be addressed.>> >>
Do you know how (or if) Cobb handles the problem of spinning>> both the bicycle's wheels and getting the rider to pedal in>> wind-tunnel tests?>>
The wind-tunnel pictures that I've seen seem to show riders>> crouching motionless on bikes whose wheels aren't moving,>> which isn't a very good imitation of the real thing.>>
. . . I do see pedal cadence, so the rear wheel is moving. The text is a little unclear about whether this is unlike other wind tunnel test platform--they may mean only that it's raised to eliminate ground effect (presumably from the tunnel, not normal ground effect, but maybe not).
But the front wheel is probably more important than the rear, since the rest of the bike passes through its turbulence, and I can't find anything about it spinning.
The middle picture ("straight ahead") shows the front spokes apparently motionless, but it could be just the illusion of a high-speed snapshot or perhaps only a posed picture, not live and spinning.
There might be a small patch under the front wheel with rollers too small to see in the picture, but the patch might be just the reflection from the rim on the polished metal surface. The text says only that "the front wheel stands free, without any supports to throw off drag readings."
If they have an amazing set of powered front rollers that spin the front wheel up to the speed indicated on the rear wheel, I think that they'd mention it.
Thanks for the link--I like to peer at such stuff.
psycholist wrote:> I'm building up a TT bike. I've got it all put together, but it's got a > very conventional seatpost. Does anyone have any good data that would point > to whether or not investing in a good aero seatpost would make any > meaningful difference? I'm considering one of the Corima carbon posts, but > I don't need to toss $125 if it's just a waste. On the other hand, my > objective is to assemble the fastest bike I can and that's one area that > remains to be addressed.>
Thanks for any insights.>
it costs about that for a carbon post anyway, so if you want a tt bike, & it looks the part, why not?
