Thought this was interesting from our own qrman, september 15th 1998, rec.sport.triathlon:
(John Cobb) performed a test with the lotus and a standard vitus, one
of the old whippy ones. he swapped the forks, the whippy vitus frame
w/ lotus fork beat the lotus frame w/whippy vitus fork. there is a story
which i had second hand which would corroborate this from the GAN team,
which did the same test, round tube bike, swapped forks, but on the
velodrome, not the wind tunnel, and got the same result.
i also spent the weekend with steve hed at the same show, at another such
session a vitus / hooker experiment was conducted, whereby the hooker,
obviously much better aerodynamically than the vitus, was the model for a
vitus makeover. all the external cables were taken off the vitus (hooker's
cables were all internal), and the vitus accessories were replaced with
hooker's, the hooker seatpost, fork, etc. the "new hookerized" vitus
tested almost equivalently to the hooker.
john cobb has all these numbers, and he may or may not give them to me. i
had a long talk with john and craig turner at interbike, the three of us
had a little impromptu symposium on exactly how much data these gentlemen
possess should be available free, for public consumption, when this kind
of extra work they do with regard to bike fit, biomechanics, aerodynamics,
etc., is the only thing that separates them from a dealer like, say,
performance, who does no such testing (that i know of). this kind of
stuff is the "value added" nature of these retailers, and it is what
differentiates them. so they only reluctantly want to divulge the
information en masse, they'd rather do it selectively, preferably after
deposits have been paid, which i both undestand and concur with.
so, therefore, since i don't currently possess the numbers from john
cobb's and steve hed's tests mentioned above, my conversations with them
(according to what i've been told by certain science minded types on this
NG) didn't exist. my guess is that, for some of you who are interested in
purchasing the right bike or wheel, you might consider a similar
non-conversation with these gentlemen, as they'd probably be happy to
share with you individually what they share with me.
i'm trying to reach mike burroughs to have the same non-conversation. he
and i have some views in common, and some in opposition. steve hed and
john cobb both agree that their tests routinely show that a well designed
aero fork is .2 to .3 lb of drag at 30mph better than a standard fork, i'd
like to see what burroughs would say about that.
speaking of burroughs and forks, his giant fork is actually a very good
one aerodynamically, which you'd expect from the guy who designed the
lotus. i'm sure it is more aero, head on, than our carbonaero. i do have
the numbers on the carbonaero, and it is very frankly not in the same
league as a
lotus fork aerodynamically in a straight on wind. it is only
.1 lb better than other fairly aero "non-aero" forks. but we didn't
really build it for that application. we hoped to make a fork that would
make it possible to ride in the aero position with a fairly high cross
section front wheel, in a crosswind, with the torque applied to the
steering reduced to a minimum. we felt that this would yield a more aero
fork/wheel complex, and make riding such a setup safer and truer than
otherwise. this we accomplished, i do have the torque numbers somewhere
if you'd really like them posted.
i have rely heavily on tests performed by steve hed and john cobb, with
relevent input from others such as richard bryne, ralph ray, and craig
turner, when deciding on what to concentrate in frameset design.
certainly i have access to all their testing data. but it's not mine,
it's theirs, and i can only share it if/when they agree, with they are
largely reluctant to for reasons stated above.
but as steve hed put it to me this morning, fully half the aero frames he
tests are less aerodynamically efficient than round tubed bikes, and the
ones that are more efficient are only marginally so (forks and wheels are
specifically excluded from that category, as there are more significant
diffences among models in these two categories). it is therefore quite
easy to spend a lot of money on a poor selection.
i think hiding cables is an interesting idea, i've seen test results that
suggest that's pretty important. but i don't know which cables are the
most important to hide, around the handlebar? along the top and
downtubes?. i also have no idea how important an aero seatpost is, hooker
had a really great one, it seems, and the last time i was down there in
his factory i collected all his remaining sub-assemblies of his posts, so
we could get a head start on working on something like that ourselves, to
see if there is some validity there.
qrman
Want: 58cm Cervelo Soloist. PM me if you have one to sell
Vintage Cervelo: A Resource