Re: Fairings for upright bikes?

'Bents aren't the only parallel universe to "jersey pros." Rando bike
riders have been developing quality full-feature bikes for decades.
Moreover, the French rando style focuses on integrated design, in
contrast to the British "strap-on" style, in a way that could boost the
whole bike scene. More than just niche market people would go for bikes
that seamlessly and stylishly included all the generally useful
functions.

I still also think that if aero was properly included in the list of
obviously and generally desired functions---riders of any speed can
hugely benefit from far-easier riding into any headwind or
crosswind---that elegant and natural solutions could be developed which
include stability.

Mike Mowett's set-up to me seems incomplete and not necessarily
versatile in terms of result-goals, but he has fun with it. I think one
could reduce and stabilize the nosecone to harmonize much better with
an aero and possibly extend down a bit to shield legs, as I've
mentioned. An aero jersey could replace the bodysock. And he's doing
nothing with a saddle fairing / pushplate or rear-area fairing. But I'm
not sure that R&D is his thing. He's mostly out there having fun, which
is great.

The current top HPV records (81mph sprint, 50+mile-hour) were done with
Varnas, a no-tech-budget bike. No wind-tunnel.

Again, I'm surprised that the tinkering, workshop world of bikes hasn't
done anything with improving upright aero beyond the UCI regs which
statistically affect no riders. (The 1% of sport riders who race, and
only a small part of their weekly mileage, are an astonishing case of
the tail wagging the dog.)

I strongly remind folks that ultralight bikes didn't appear thanks to
UCI regs or trends! A regulated racing mentality brings ZERO bike
gains. The desire to go fast OUTSIDE of regs and strictures is what
brings the bike gains. (Training gains, however, do come from
racers---HRM, SRM, doping...)

Bikes and tech go together and have very low overhead costs compared to
the R&D of other sports, I suspect. Heck, I'm no techy and I've done
innovative research. So far my upright aero concepts are the most
advanced I've seen for real world application. That fellow's Tailwind
panniers and rather standard front windshield are nice but not
integrated or very optimized at all. It's great that he's using and
benefiting from them, but I think my R&D went quite a bit farther---not
to production utility, though. I'd love to see him using a shield
shaped to an aerobar and front hardshell aero pans with integrated
light/fender/rack!!!

I appreciate that weight has been determined to be hugely
important---bike R&D shows no limits here (with 7-10-lb raceable
uprights). Aero has also been determined to be hugely important---with
the only exploring being in the range of statistically irrelevant
UCI-tri-legal gimmicks. (Again, pro teams can do all that R&D on their
own. That leaves, what, a million sport riders riding millions of
NON-racing miles with ZERO exploration on their aero behalf.)
Thankfully, carbon/ti can solve both the concerns of weight and aero.
Let's just start applying it in light of other current innovation.

And let's include other features, too, while we're at it---stylish
integrated fenders (go with fairings easily), internal light wiring,
lights merge with fairings and carbon frames easily, hidden suspension,
cargo spaces within fairings. Remember, none of this has to appear very
obtrusive. The result would look no more outlandish than any of today's
other carbon Y-frame bikes---and would be far faster and far more
functional. An aero helmet could look cool, too. With good design/color
scheme the result could easily look LESS garish than many of today's
jersey pros.

--JP

Quoted message said:

Again, I'm surprised that the tinkering, workshop world of bikes hasn't
done anything with improving upright aero beyond the UCI regs

But they have... The Moulton Liners still hold the upright world record
AIUI. See here... http://members.localnet.com/~milliken/liner/liners.htm

However, if you're going to work on an aerodynamically optimised bike it
makes a lot of sense to start with something that gives you a better
start! Since a lot of the work in aero is minimising frontal area then
that rather leads you to a recumbent.

One of the truly great things about the DF upright is it's very
versatile, does lots of jobs reasonably well and can easily be carried
and stored. Start adding integrated fairings etc. and this gets
destroyed to some extent.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Quoted message said:

Again, I'm surprised that the tinkering, workshop world of bikes hasn't
done anything with improving upright aero beyond the UCI regs

But they have... The Moulton Liners still hold the upright world record
AIUI. See here... http://members.localnet.com/~milliken/liner/liners.htm

However, if you're going to work on an aerodynamically optimised bike it

I'm talking more about working with a common bike format and giving it
sizeable gains with a few simple add-on devices.

Quoted message said:

makes a lot of sense to start with something that gives you a better
start! Since a lot of the work in aero is minimising frontal area then
that rather leads you to a recumbent.

Yeah. But we shouldn't just neglect uprights. They can be helped a LOT.

Quoted message said:

One of the truly great things about the DF upright is it's very
versatile, does lots of jobs reasonably well and can easily be carried
and stored. Start adding integrated fairings etc. and this gets
destroyed to some extent.

To make it truly versatile people already add on tons of stuff---in
ugly, unstable ways that slow them down. Once you include the great
ideas of packs/pans/racks/fenders/lights you've added to the bare
upright already. How to make these additions and not add to the clutter
and downsides? But actually these additions are just great
side-effects, in a sense. I guess my mission is two-fold. But it starts
with speed: race-legal ways to add speed to an upright are
intentionally curtailed and right now add no versatility. But I think
that doing the laundry list is a good idea and does add 1-2mph: fast
wheels, aerobar, aerohelmet, tidy up the rest. Non-legal enhancers
would open a HUGE new range of options to enhance fun for 99% of ridden
miles. I still wonder why they aren't explored. Haven't heard a good
answer yet. The market is actually big for this. I still think that a
couple nicely designed carbon fairings could nicely integrate in with
any current carbon aerobike and add a few mph---and greatly improve
versatility, convenience and harmonious appearance (compared to current
ways of adding functionality). Anyone who wants to give up the free
speed and functionality and do a race could just click off these
devices from their QR's and have a race-legal bike once again.

Consider once again:

*A single carbon unit that zipties to the front and integrates with an
aerobar and provides storage under the bars and in the sides as per
usual front pans. It attaches/removes via a QR device as a single rigid
unit. Adds 2mph. Has cool graphics. Weighs one pound. Includes its own
fender and light-aperature and hookup (install light, add a pound: no
aero deficit or appearance intrusion). Does 5 functions in one. Solid,
secure, waterproof, simple, harmonious with design of bike.

*A single unit that zipties to the rear and fairs the
back/butt/legs/rear of bike and provides the usual saddle area storage
plus rear-pan storage, includes its own fender and rear light set-up. 5
common things in one unit. Weighs 2 pounds. Adds 1mph. Cool graphics.
On/off via QR. (Same other virtues.)

*Aero helmet, faired-pedals, batwing-jersey, (batwing leg-tights?). Get
the graphics right to avoid shock (classy, subdued but snappy, fitting
in with rest of bike graphics). Add 1mph.

*All designed shapes and graphics of bike and accessories are
integrated and tasteful. Bike is carbon in a common faired shape. The 2
add-on 5-function faired units and accessories don't alter the previous
look of the curve-tube aero-shape carbon bike. The bike can even have
comfy touring geometry---and include some suspension. Final product
enhances versatile functionality and gives 4mph free speed (and huge
reduction of effort and increaste in stability in most typical
headwind, crosswind scenarios as compared to other loaded bikes). You
end up with faster, comfy, dry, bike you can use at night and tour or
run errands with. Adds $1K to the $3K tag of the bike and yer out the
door.

--JP

Quoted message said:

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Quoted message said:

Mike Mowett's set-up to me seems incomplete and not necessarily
versatile in terms of result-goals, but he has fun with it. I think one
could reduce and stabilize the nosecone to harmonize much better with
an aero and possibly extend down a bit to shield legs, as I've
mentioned.

Quoted message said:

From the picture it looks as if he's using a ZZipper type fairing, wide

enough to accommodate a standard drop bar. An aerobar would be
narrower, but project further forward, which might not be a good idea.
I used to have an aerobar on my touring bike, but it always seemed too
twitchy. These days, I use a nice curvy waist pack as my bar bag. I
take the waiststrap over the bars and round to support the pack from
underneath. When I hit a headwind I put my forearms on the bars and
hook my thumbs into the pack's carrying handle. It seems just as
effective, and also keeps some of the rain off my thighs. I suspect a
proper fairing would do even better.

However - no way would I ride in that position all the time. Too
dangerous. I need to be able to reach the brakes and gears, and have a
stable position that allows me to relax and enjoy the scenery sometimes
without losing too much aero advantage, but when I really need to be
streamlined, why should the bars and brake levers be sticking out in
the breeze?

Here's my proposal - three components that may be used separately but
should work well together for maximum comfort and streamlining:

1 A 'blade' that attaches to the down tube and acts as a front
mudguard. It can carry lights, and all the other stuff (tools, spares,
pump, drinks system, snacks) that would otherwise go on the frame,
under the saddle, or in your jersey pockets.

2 A bar bag/fairing just large enough cover the forearms in a full
aero tuck, with intergrated rain cape/body sock that tucks away when
not needed. It may fasten to the bars or the blade, but it is quickly
detachable and can easily go with you whenever you get off the bike.

3 A set of aero bars with handgrips that are lightly sprung and rotate
out and down when you put pressure on them. When tucked they are hidden
behind the fairing, but if you come right out of the saddle they move
to a wide "cyclocross drops" position, providing a form of suspension
in intermediate positions.

Jenny Brien said:

However - no way would I ride in that position all the time. Too
dangerous. I need to be able to reach the brakes and gears

It is possible to have brakes and gears usable both from aerobars
and from the non-aero position:
http://jtekengineering.com/doublecontrol_l.htm
http://jtekengineering.com/AeroBrake.htm

(Doesn't address your other points, I know.)

Quoted message said:

I'm talking more about working with a common bike format and giving it
sizeable gains with a few simple add-on devices.

I suspect your "simple add on devices" wouldn't be as simple as you like
to make them sound... ;-/

Quoted message said:

To make it truly versatile people already add on tons of stuff---in
ugly, unstable ways that slow them down.

But the key is often you can take it straight off too, independently of
anything else... With this scheme, if I want lights I also need
panniers and windshield too which means that the extra flexibility
rather ironically lacks flexibility.

Quoted message said:

Once you include the great
ideas of packs/pans/racks/fenders/lights you've added to the bare
upright already. How to make these additions and not add to the clutter
and downsides? But actually these additions are just great
side-effects, in a sense. I guess my mission is two-fold. But it starts
with speed: race-legal ways to add speed to an upright are
intentionally curtailed and right now add no versatility. But I think
that doing the laundry list is a good idea and does add 1-2mph: fast
wheels, aerobar, aerohelmet, tidy up the rest. Non-legal enhancers
would open a HUGE new range of options to enhance fun for 99% of ridden
miles. I still wonder why they aren't explored.

To borrow a line from UK motoring journo Jeremy Clarkson, "if you want
to build a fast car, start with a fast car". Upright racers are built
to conform to UCI specs of no aerodynamic aids and contrived rules of
bottom bracket placement and wheel size. It makes much more sense to
build a fast bike from scratch in a recumbent mould because they are
better bases for speed than UCI regs, which are a basic for making the
machine less important than the rider. The IHPVA main records aren't
held on 'bents because they must be, but because they're the fastest way
to build bikes /if/ you're building in aero from the ground up. So
people tinkering for speed and not bothered by the UCI generally tinker
with recumbents because it's a provably better way of achieving the
design goal.

You /can/ improve the aero of an upright, but you'll lose a lot of the
inherent flexibility and you still won't do as well as a 'bent.

Quoted message said:

Final product
enhances versatile functionality and gives 4mph free speed (and huge
reduction of effort and increaste in stability in most typical
headwind, crosswind scenarios as compared to other loaded bikes). You
end up with faster, comfy, dry, bike you can use at night and tour or
run errands with. Adds $1K to the $3K tag of the bike and yer out the
door.

Or I could spend the same money on a recumbent which already exists,
takes loads better (weight can go under the rider, between the wheels)
and is fundamentally more comfortable (no weight on my arms and a big
comfy chair with no call for contrived padding on my clothes).

That way I have 2 bikes and use the one best for purpose, rather than
try and get one thing to do everything.

There is a market for doing everything in one, but it's quite rarified
at the 4 figure price level and usually includes things like easy
disassembly and portability (like the NS Moulton, Airnimals and Bike
Fridays).

I don't think it's a /bad/ idea, just not /quite/ as good as you suggest.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

On Fri, 16 Jun 2006 09:25:30 +0100, Peter Clinch <[email hidden]>

Quoted message said:

To borrow a line from UK motoring journo Jeremy Clarkson, "if you want
to build a fast car, start with a fast car". Upright racers are built
to conform to UCI specs of no aerodynamic aids and contrived rules of
bottom bracket placement and wheel size.

Oh, [censored]. Diamond frame bikes were designed to conform to human anatomy and
the variety of surfaces on which bikes are used. UCI rules simply codify and
standardize this for the purposes of sport. That would be an athletic
competition between riders, not a contest to see who can design the machine best
specialized for a particular course. Sorry for the rant, but I'm irritated with
the UCI getting blamed for the persistence of the diamond frame bike. As if: a-
the diamond frame bike were a bad thing; and b- racing rules make a difference
to utility bike purchases. UCI rules also a number of other features we see on
bikes everyday. Let's put it this way, NASCAR rules don't inhibit the use of
fuel injectors on street cars.

Quoted message said:

It makes much more sense to
build a fast bike from scratch in a recumbent mould because they are
better bases for speed than UCI regs, which are a basic for making the
machine less important than the rider. The IHPVA main records aren't
held on 'bents because they must be, but because they're the fastest way
to build bikes /if/ you're building in aero from the ground up.

AND if you are building for a closed, smoothly paved course with little
elevation change and no tight corners.

Quoted message said:

So
people tinkering for speed and not bothered by the UCI generally tinker
with recumbents because it's a provably better way of achieving the
design goal.

You /can/ improve the aero of an upright, but you'll lose a lot of the
inherent flexibility and you still won't do as well as a 'bent.

True.

Quoted message said:

Quoted message said:

Final product
enhances versatile functionality and gives 4mph free speed (and huge
reduction of effort and increaste in stability in most typical
headwind, crosswind scenarios as compared to other loaded bikes). You
end up with faster, comfy, dry, bike you can use at night and tour or
run errands with. Adds $1K to the $3K tag of the bike and yer out the
door.

Or I could spend the same money on a recumbent which already exists,
takes loads better (weight can go under the rider, between the wheels)
and is fundamentally more comfortable (no weight on my arms and a big
comfy chair with no call for contrived padding on my clothes).

That way I have 2 bikes and use the one best for purpose, rather than
try and get one thing to do everything.

Only two <g>?

Ron

Quoted message said:

There is a market for doing everything in one, but it's quite rarified
at the 4 figure price level and usually includes things like easy
disassembly and portability (like the NS Moulton, Airnimals and Bike
Fridays).

I don't think it's a /bad/ idea, just not /quite/ as good as you suggest.

Pete.

RonSonic said:

On Fri, 16 Jun 2006 09:25:30 +0100, Peter Clinch <[email hidden]>

Quoted message said:

To borrow a line from UK motoring journo Jeremy Clarkson, "if you want
to build a fast car, start with a fast car". Upright racers are built
to conform to UCI specs of no aerodynamic aids and contrived rules of
bottom bracket placement and wheel size.

Quoted message said:

Oh, [censored]. Diamond frame bikes were designed to conform to human anatomy and
the variety of surfaces on which bikes are used.

No, they were an obvious evolutionary development from the hobby horse,
which emulated a horse.

If diamond frames "conform to human anatomy" then there would be no need
to have rules about how far ahead of the seat the bottom bracket can go,
it just wouldn't be relevant, because there would be nothing to gain by
moving it forwards.

Quoted message said:

UCI rules simply codify and
standardize this for the purposes of sport. That would be an athletic
competition between riders, not a contest to see who can design the machine best
specialized for a particular course.

Which I specifically said ("which are a basic[sic, meant basis] for
making the machine less important than the rider"😉, so it's not like
that's news to me...

Quoted message said:

Sorry for the rant, but I'm irritated with
the UCI getting blamed for the persistence of the diamond frame bike. As if: a-
the diamond frame bike were a bad thing;

I never said it was. I own a couple, after all.

Quoted message said:

and b- racing rules make a difference to utility bike purchases.

Not strictly true. The exclusion of "development classes" like the
sailing world has means that the primary bikes in the public eye remain
diamond frames. It would be news to most people that the fastest bikes
available are /not/ what they typically see people racing on.

Quoted message said:

UCI rules also a number of other features we see on
bikes everyday. Let's put it this way, NASCAR rules don't inhibit the use of
fuel injectors on street cars.

But they have no effect on the overall form of a car, so it's not really
the same thing.

Quoted message said:

AND if you are building for a closed, smoothly paved course with little
elevation change and no tight corners.

So how come the UK End to End record, which is not smoothly paved over
it's 800+ miles, has numerous hills and a few tight corners, is held by
a faired recumbent?

You won't do it on the Varna Diabolo, but that's not the only game in town.

Quoted message said:

Only two <g>?

I actually have 5 (though the Muni isn't strictly a bike...), so r're in
full agreement here!

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

RonSonic said:

Diamond frame bikes were designed to conform to human anatomy and
the variety of surfaces on which bikes are used.

No, they were an obvious evolutionary development from the hobby horse,
which emulated a horse.

I think you're understimating the broad range of design exploration in
the 1860s through 1900s. There were enough variations in design to
allow plenty of testing the effect of crank-to-saddle fore-aft
postions, including some early models with cranks far forward of the
axle. We gradually evolved to the "knee over pedal spindle" rule of
thumb because it worked, not because we were imitating horses.

Quoted message said:

If diamond frames "conform to human anatomy" then there would be no need
to have rules about how far ahead of the seat the bottom bracket can go,
it just wouldn't be relevant, because there would be nothing to gain by
moving it forwards.

I think it comes down to this: Physiologically, there is nothing to be
gained by moving it forward a small amount. Try riding one of the new
Electra bikes, a sort of semi-chopper design, if you doubt. It's OK
for relaxed cruising, but any sort of hill is a major challenge.

If you kick the bottom bracket far enough forward, you'll get a bit of
aerodyamic benefit. But the aerodynamic advantages of a recumbent
aren't very valuable for most cyclists, since they don't exert
themselves enough to take advantage of them. And they aren't that
great anyway unless the recumbent is faired.

For about 99% of the biking population, the only advantage of a
recumbent would be comfort. That's balanced by lower stability on
rough surfaces, more difficulty climbing hills, less visibility in
traffic, more difficulty storing & transporting by car, bus, train etc,
more difficulty carrying up stairs or just walking the bike, more
difficulty finding certain repair parts, and of course cost.

Recumbents are really interesting, from a "design challenge"
standpoint. They're fun to ride, as a change of pace. But the overall
balance of advantages & disadvantages clearly goes to the upright bike.

- Frank Krygowski

Quoted message said:

Recumbents are really interesting, from a "design challenge"
standpoint. They're fun to ride, as a change of pace. But the
overall balance of advantages & disadvantages clearly goes to the
upright bike.

As usual, Frank is loathe to use the common qualifying expression, "IMO".
(Even though he's right in this case. {pause} IMO! <eg> )

Bill "Frank knows best" S.

Back in the '70's and early 80's, a whole bunch of people in my cycling
club tried using full fairings. They all got rid of them because they
were so terrible in a crosswind.

In uk.rec.cycling [email hidden] twisted the electrons to say:

Quoted message said:

For about 99% of the biking population, the only advantage of a
recumbent would be comfort.

Whilst the vast majority of the "trundlies" probably never exceed a
ground speed of ~10mph they probably do at times exceed an air speed of
~10mph (ie: cyling into a headwind) at which point they will start to
benefit from the improved aerodynamics.

Quoted message said:

That's balanced by lower stability onrough surfaces,

Well I wouldn't pick a 'bent for riding, say, The Old Coach Road section
of the Coast-2-Coast (though I suspect someone's had a go!) but for the
sort of rought surface I'd expect to meet say commuting a 'bent should be
fine. Indeed ATM my commute involves a gravel path through some road
works without any problems ...

Quoted message said:

or just walking the bike,

Depending on the 'bent, grab rear of seat and push forwards, lean
left/right to turn left/right ... No difficulty there!

Quoted message said:

more difficulty finding certain repair parts

AFAICS the only custome parts on my 'bents are the frame (+ handlebars)
and the rear racks - everything else is a standard bike part.

Quoted message said:

and of course cost.

Well true, but remember to compare like with like ...

Quoted message said:

But the overall balance of advantages & disadvantages clearly goes to
the upright bike.

In your opinion, not necessarily in the opinion of others ...
--
These opinions might not even be mine ...
Let alone connected with my employer ...

in message <[email hidden]>,

(') said:

For about 99% of the biking population, the only advantage of a
recumbent would be comfort.

Comfort is a real benefit, of course - although personally I don't find
diamond frames uncomfortable.

Quoted message said:

That's balanced by lower stability on
rough surfaces,

Really?

Quoted message said:

more difficulty climbing hills,

Granted.

Quoted message said:

less visibility in traffic,

Empirically that does not seem to be true - quite the reverse.

Quoted message said:

more difficulty storing & transporting by car, bus, train etc,
more difficulty carrying up stairs or just walking the bike,

All these I'd grant you...

Quoted message said:

more difficulty finding certain repair parts,

Largely due to smaller relative market size.

Quoted message said:

and of course cost.

Ditto.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; ... exposing the violence incoherent in the system...

Quoted message said:

Back in the '70's and early 80's, a whole bunch of people in my cycling
club tried using full fairings. They all got rid of them because they
were so terrible in a crosswind.

Fairings are better today. Partials are a good option. Curved side
panels and lower bikes really improve crosswind handling.

This thread relates to useful partial fairings on uprights. All
suggested design concepts are highly curved in side-profile...and,
because this thread also includes the subject of utility/tour benefits
of aerodynamics, it's worth noting that the suggested fairings would be
superior in crosswinds compared to other panniers.

Alistair Gunn said:

In uk.rec.cycling [email hidden] twisted the electrons to say:

Quoted message said:

For about 99% of the biking population, the only advantage of a
recumbent would be comfort.

Whilst the vast majority of the "trundlies" probably never exceed a
ground speed of ~10mph they probably do at times exceed an air speed of
~10mph (ie: cyling into a headwind) at which point they will start to
benefit from the improved aerodynamics.

I note that this thread relates to the interests of the huge market in
sports cycling, not a theoretically blobular general population.

I also note (again) that 99% of sport riding is unregulated yet still
gungho and would benefit from any and all aero aides. For some reason
the rules that restrict 1% of sport riding miles (actual race events)
are allowed to influence the way sports riders ride all the rest of the
time. No reason for that. Again, this is a big demographic and it loves
spending money. More money more better is a dominant view. All any
pricey bike bit needs to succeed is a trend to follow or a star rider.
The problem is that star riders are only in racing at present. But, as
mentioned, touring is the new black. I expect we'll see some neat
full-featured integrated bikes soon, in carbon, that don't care about
regs.

PS: Here are a couple links to images of carbon aero addons:

http://novosport.de/en/?Products:Boxes_%26amp%3B_tail_fairings
(see the MTB trunk at the bottom of the images line-up)

http://outyourbackdoor.com/Images/rp1236.jpg
(I forget where I got this image, but it shows that a rear trunk can
have a nice look and an aero shape)

Simon Brooke said:

in message <[email hidden]>,
[email hidden] ([email hidden]'😉 wrote:

[snip other recumbent matters]

Quoted message said:

Quoted message said:

That's balanced by lower stability on
rough surfaces,

Really?

[snip]

Dear Simon,

Yes, really--recumbents are less stable.

Or so I gather.

Most people have more control over a bouncing bicycle when they stand
on the pedals and lean forward over the handlebars, not when they lie
on their backs like turtles in hammocks.

Then there's something to do with polar moments and lower centers of
gravity. Weirdly, the tall-boy circus-style bicycles are more stable
at low speeds.

After kind folk here at RBT explained the physics to me, I realized
that I'd been watching recumbents wobbling slowly (and happily) along
my bike path for years, but I'd never connected their unsteady
progress with their handling characteristics.

I assume that the recumbents that I see would stop wobbling at higher
speeds, but any cop would stop them and ask the riders if they'd been
drinking.

Cheers,

Carl Fogel

In rec.bicycles.tech said:

On Fri, 16 Jun 2006 18:09:21 +0100, Simon Brooke
<[email hidden]> wrote:

Quoted message said:

Quoted message said:

in message <[email hidden]>,
[email hidden] ([email hidden]'😉 wrote:

Quoted message said:

[snip other recumbent matters]

Quoted message said:

Quoted message said:

Quoted message said:

That's balanced by lower stability on
rough surfaces,

Really?

Quoted message said:

[snip]

Quoted message said:

Dear Simon,

Quoted message said:

Yes, really--recumbents are less stable.

Quoted message said:

Or so I gather.

Try taking a long-handled garden tool and balance it with the end of the handle in the
palm of your hand. Then try to balance it with the business end in the palm of your
hand.

With a high center of mass, your hand has more time to correct the fall of the tool;
with a low center of mass, your hand has less time.

Another example of this is an old-fashioned pedulum-style metronome. Faster tempi are
given with the weight low on the shaft, near the pivot.

In practice this is mostly a non-issue, even with a long wheelbase recumbent. With
some practice a rider on a long long wheelbase recumbent should be able to balance at
speeds down to about 3 mph, walking speed.

If you do end up tipping over at low speed--it happens sometimes--you don't have far to
fall, damaging only your pride and dignity.

Quoted message said:

Most people have more control over a bouncing bicycle when they stand
on the pedals and lean forward over the handlebars, not when they lie
on their backs like turtles in hammocks.

Not all recumbents have the rider lying on his back.

Quoted message said:

Then there's something to do with polar moments and lower centers of
gravity. Weirdly, the tall-boy circus-style bicycles are more stable
at low speeds.

I took a ride once on a six-foot high-wheeler (ordinary). It was easy to ride once I
got started; it was amazingly stable. But then I realized my head was about 10 feet
off the ground, even with the nearby rooflines, and that I would have to get off the
thing eventually. Damn near spooked me until the owner of the bike talked me through
the process. It wasn't difficult, and I'm sure one can learn to ride and get on/off
these things gracefully, but the safety bicycle is as high as I care to go.

--
Bill Bushnell
http://pobox.com/~bushnell/

[email hidden] wrote:
[ ]

Quoted message said:

Yes, really--recumbents are less stable.

Or so I gather.

Most people have more control over a bouncing bicycle when they stand
on the pedals and lean forward over the handlebars, not when they lie
on their backs like turtles in hammocks.

That's not how to handle a bike at higher speeds. Longwheelbase 'bents
like the Tour Easy are famous for rock solid high speed handling. When
you have a solo bike with a tandem-like wheelbase you can readily
design for huge comfort and stability---and when made in carbon I think
they're around 25lbs. Also, braking for 'bents is far more powerful and
there is no risk of pitching forward for most models.

About hard to find spare parts: malarkey. The unique parts of a
recumbent---the seat?---break no more often than the frame on any bike.
All the rest are often quite standard (especially if any smaller wheel
is of BMX size). OK, there are a very few specialized parts. This was a
breakthru for me when I first became familiar with 'bents: how they
used the same parts, basically, except for an often far simpler
monotube frame (and more complex seat in some ways, in other ways less
so---an elite upright saddle has a lot of complexity in a small area).

But how 'bout them fairings for uprights?

--JP