Quoted message said:I like this subject and so will try again from a different approach...
I think it's interesting, too, but I'm not as hopeful as you!
Quoted message said:Is there anything else people could do to get "free" speed? Is there a
list of such things and the gains they give? There's a webpage listing
a couple dozen race-legal things to save 3 minutes in 40km. "Illegal"
enhancers would likely be far more effective---and freely available to
anyone not in a race---which is 90-99% of miles ridden, as stated.
Speed is of interest for a couple reasons, of course. It's fun, it's
effective (extends range, makes errands quicker) and it's good
training.
I'm not going to say your ideas aren't feasible. But I don't think
many people are going to be interested.
For me, if I could do 75 leisurely miles in a day (instead of, say, 50)
the extra range would be nice for touring. Alternately, it would mean
I could sqeeze in a bike ride to a store across town, when otherwise
I'd have to use a motor vehicle to make it in the allotted time.
But I think very few people are going to be motivated by those factors.
I think that, for most people, a bike ride is just a bike ride. They
don't particularly care about getting a _little_ bit further. And
unfortunately, I doubt you'll be able to make more than a little
improvement.
Decades ago, I sketched up some ideas that addressed what you're
talking about. I think it started with me looking at my handlebar bag,
a very square-edged thing breaking its way through the headwind. I
eventually built a large capacity, lightweight, aero handlebar bag.
And I've already discussed the benefit I experienced with Tailwind
panniers. I also went to oval spokes on my front wheel, and I played
some with a Zzipper fairing and with fabric rear wheel spoke covers,
those things that look like a disk rear wheel. All this was on my
uprights, understand.
I believe some of these things made a difference, although I wasn't
disciplined enough to measure the difference. But most did not stay on
the bike. In particular, the Zzipper fairing was inconvenient for
getting the bike into and out of the basement, car, etc, and it rumbled
annoyingly. I didn't like its mounting system, and it started getting
hairline cracks.
The rear spoke covers made inflation and flat fixing a bit of a pain,
and at some point, it somehow misaligned to where my brake shoe wore
away a bit of the fabric.
Ultimately, I dumped everything except the handlebar bag, and its
contribution is probably negligible. However, I still use the Tailwind
panniers on most tours (despite their lousy mounting system), and I've
occasionally put the rear spoke covers on for relatively flat
centuries.
Overall, I don't believe you can easily make a difference that's
significant to the average dedicated cyclist, let alone the average
person-on-a-bike. I think the minimal improvements, if any, will be
overcome by the minor hassles inherent in almost any add-on. And the
improvements will be minimal - nothing like the 75 vs. 50 mile thing I
mentioned above.
Having said all that, if I were going to do this, I'd concentrate on
the wheels (actually, spokes) and the rider's legs, unless you want to
put up with a Zzipper fairing.
Perhaps fairing the top half of the wheels with a fender reaching
forward to the point directly in front of the hub would help, esp. if
it had side skirts, so the spokes don't churn forward through the
relative wind. (Disk front wheels are unstable, but a fender with side
skirts may be less so.) The rear fender/fairing could be blended into
the seat tube. A disk rear wheel, or spoke cover, in addition to the
rear fender/fairing would help, but they should be designed better than
the ones I have.
A taller version of the Tailwind front pannier shape might work, sort
of like a lower fairing on a motorcycle, keeping the spinning legs &
feet shielded. ISTR Ken Kifer built his own touring panniers that
were not purposely aero, but did extend up high like that. His web
page has pictures, I think.
I think details like brake covers, derailleur covers, etc. are _very_
negligible. In general, fairings of any type seek to keep airflow
attached and to reduce the size of the wake that's "stirring" the air,
since that's an energy sink. But I'd think the front brake's wake
extends back only an inch or so, when it gets swallowed in the wake of
the wheel, fork and head tube. Not much energy goes there. Likewise,
the derailleurs are already out in wakes that will not be made smooth.
Trouble is, the big wakes make the most difference, and you need big
hardware to suppress the big wakes. It's hard to add that big hardware
without significantly decreasing the portability and convenience of a
bike.
Although I'm not much of a recumbent fan these days, I really think
you'd be better off playing with partial fairings for recumbents.
- Frank Krygowski