over versus under

"Andy Gee" <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal data about which type is faster, more mechanically efficient, more
physiologically efficient, has less drag, etc?

thanks!

--ag

Can't point you to any studies, but it's very clear that USS is less aerodynamic. Put your hands in
the praying hamster position, note your shoulder position, now drop your hands to your side, note
how much wider your shoulders are in this position? Add in the width of your arms next to your body
and it is 6-12"(more or less) wider in the USS position. (some guys worry about the aero factor of
1/2" wider tires!) I used to drop my arms off one at a time to relieve numbness from CT (OSS) and
you could feel the air hitting that arm that normally would pass by me undetoured. Not to say that
in every day riding it would matter at all. Ride USS now and wouldn't give much weight to either
side. Small factor.

Andy, Even when I was a DF rider my wife often asked, "Over or Under". Both seemed equally
efficient, but sometimes one of us was faster. I'm not sure about the mechanical efficiency, but
clearly there was less drag on those occasions. Hope this helps bg

Andy Gee said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal data about which type is faster, more mechanically efficient, more
physiologically efficient, has less drag, etc?

thanks!

--ag

My Vision R50 was USS and my Baron is OSS, it depends on the bike.

If I had a standard recumbent I prefer USS but with the Low Rider you have no choice however I
don't mind it

"Andy Gee" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal

data

Quoted message said:

about which type is faster, more mechanically efficient, more physiologically efficient, has less
drag, etc?

thanks!

--ag

a&b <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

Andy, Even when I was a DF rider my wife often asked, "Over or Under". Both seemed equally
efficient, but sometimes one of us was faster. I'm not sure about the mechanical efficiency, but
clearly there was less drag on those occasions. Hope this helps bg

I prefer under for myself. I don't have to work as hard and find that pressure applied in some areas
is much more satisfying. Efficiency really isn't what I'm after, just an enjoyable ride, and usually
if the event is sustained a little longer both parties are happier.

rorschandt

"Andy Gee" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal

data

Quoted message said:

about which type is faster, more mechanically efficient, more physiologically efficient, has less
drag, etc?

hpv-klub.dkdefault en.aspOpen ↗

As far as the speed issue goes, I agree it depends on the bike. These bikes are USS:

reynoldsweldlabs.combikes.htmOpen ↗

JR

rorschandt <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

a&b <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

Andy, Even when I was a DF rider my wife often asked, "Over or Under". Both seemed equally
efficient, but sometimes one of us was faster. I'm not sure about the mechanical efficiency, but
clearly there was less drag on those occasions. Hope this helps bg

I prefer under for myself. I don't have to work as hard and find that pressure applied in some
areas is much more satisfying. Efficiency really isn't what I'm after, just an enjoyable ride, and
usually if the event is sustained a little longer both parties are happier.

That was certainly more information than I wanted to know, thanks. :P

-Bill Hamilton

Quoted message said:

efficiency comparisons between oss and uss.

Andy,

I'm an ASS man myself.

Easier to push the thing uphill.

Jerry

"Andy Gee" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal data about which type is faster, more mechanically efficient, more
physiologically efficient, has less drag, etc?

There's another factor to consider: safety. When I used to ride USS, while I was still new to the
bike, I managed to get a water bottle between the seat and the right handlebar. It caused me to
swerve unexpectedly into the on-coming lane of traffic with a Suburban coming! I got my steering
back just in time to miss a head-on. Switched to a hydration bladder after that.

Also, during many many miles of USS riding, I often wondered, "What would happen if I slid out
sideways? Would I be able to get my hand out from between the seat and the road?" Well it finally
happened to me on a dirt road with lots of loose sand. I was on my side so fast there would have
been no time to do anything but crash. 'Bents go over much faster than uprights once traction is
lost. Fortunately, by the time that happened I had already made the switch to OSS, and the sand made
a pretty soft landing zone anyway. BTW, that mishap also taught me the value of a tiltable steering
riser, since when it all was over, the bars were way forward. If I was using a rigid riser
(e.g., Volae) I would have been riding home with a bent riser.

Bill Anton 2001 Vision R-40 SWB, OSS Lubbock, TX, USA

"Andy Gee" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal data about which type is faster, more mechanically efficient, more
physiologically efficient, has less drag, etc?

thanks!

--ag

Non-anecdotal data- most speedbikes like those at Battle Mountain are above seat steering. Bicycles
need something like a CENTERING SPRING. UCI approved bikes have this by having a long stem that the
rider pushes forward to center the steering. Recumbents like the Tour Easy, which is the most
popular bent where I live, centers the steering by letting the rider pull back lightly on the
handlebars. I think it helps to let the rider see the handlebars so that the rider knows where the
center is.Ergonomically ASS lets the rider put instrumentation and fuel in a place where it is
easily accessable. On a Tour Easy the rider can unfold and read a map while holding on to the
handlebars with BOTH hands. In a crash under seat or side stick steering has a better chance of
damage. USS handlebars on bikes are usually the widest part of the bent and take most of the damage
even when the bike just falls over. However, on trikes USS may be the best choice in steering
controls since trikes roll over in crashes while bikes slide on their sides. You do not want to be
upside down in a trike crash with the handlebars stuck in your guts. Steering controls on a trike do
not need a strong centering spring since on a trike the rider does not have to balance.

"Andy Gee" skrev ...

Quoted message said:

i've been a recumbent rider for a few years now; very happy with it. on another discussion group,
an off-topic thread appeared about speed and efficiency comparisons between oss and uss. is there
any non-anecdotal data about which type is faster, more mechanically efficient, more
physiologically efficient, has less drag, etc?

M5 has some SRM-data on their website. m5-ligfietsen.comrecords.htmOpen ↗ (go down to
the link that says "Comparison speed etc" at bottom of page. A couple of identical models but with
OSS or USS. (Called highbar and lowbar.)

M.

I just finished a ride that put my new custom Giro mileage at 250. I have 5000 miles on my Haluzak
Leprechaun H/R USS. So take the following for what it is worth.

The Zak has a much higher bugs-in-the-teeth factor. I just can not ride it without grinning. It is
just way more fun for me to ride the USS Zak than the above seat steering Giro.

In all other factors, the Giro out performs the Zak.

As for trapping my hands under the Zak bars when I fall, that is not worth worrying about. I have
had a couple of slow speed (leaning to far in tight turns) falls and the hands go out to catch me
without my even having to think about it. It is instinctive and darn fast. This is one reason I
always wear riding gloves.

Also, in those types of fall, the bars actually catch some of the fall before my torso does. The bar
took a beating so I did not have to. Plus I don't have to worry about a bar in my face or my crotch
in the Giro Glide Flex. USS bikes are probably safer in most crashes. OK, now I have done it,
started a new arguement.

Is it true that in 2005 all above-seat-steering bents will have air bags on the stem?

Quoted message said:

Is it true that in 2005 all above-seat-steering bents will have air bags on the stem?

We airbags have been riding both above and below-the-seat-steering bents from the get-go.

Mike Rice (TE within two-and-a-half wekks!)

[email hidden] (Don) wrote in :"]news:[email hidden]:

Quoted message said:

I just finished a ride that put my new custom Giro mileage at 250. I have 5000 miles on my Haluzak
Leprechaun H/R USS. So take the following for what it is worth.

The Zak has a much higher bugs-in-the-teeth factor. I just can not ride it without grinning. It is
just way more fun for me to ride the USS Zak than the above seat steering Giro.

In all other factors, the Giro out performs the Zak.

As for trapping my hands under the Zak bars when I fall, that is not worth worrying about.

Every crash I have unwillingly participated in has done damage to my shoulders and elbows, not my
hands(save one to my head and neck on a DF some 30 years ago). It may be that people that make the
statement about trapping the hands beneath the USS bars and the ground have experience with only
one type of USS, or no experience with it at all. Damage to the shoulders, elbows and hips is a
concern to either USS or ASS on a two wheeler. Some USS designs have the hands much lower than
others, and these are the source of this Tale, IMHO. With all my vehicles,all USS, the bottoms of
the bars will strike the pavement before my hands.Trapping my hands is nearly unfeasible without a
major freak accident involving bending of rather sturdy bits of metal and oddly shaped terrain.I'd
have more serious problems in that case. Why is it constantly necessary for some to find fault with
USS? Some feel more comfortable on USS, some don't. If YOU don't like it, let it go. Let each find
his/her own way. For every reason I read for not riding USS, I can match it with one for shunning
ASS. This doesn't mean I am going to take every opportunity on this NG to run ASS(or OSS, if you
prefer) into the ground. Ride what you like. If somebody doesn't like it, tell 'em to F.O.

Rorschandt "Of course, that's just my opinion. I could be wrong." ~Dennis Miller

I have some things to add about "centering spring."

Stem and tiller, give a "centering spring" as Kochanowski explains, but there is another source of
"centering spring" that is aptly described by Professor Patterson in his "Lords of the Chainrings."

Positive trail gives a "centering spring" that is negative at high speeds, and if the head angle is
much shallower than vertical (as is the case on almost all commercial bikes) the centering spring at
low speeds will be positive. i.e. at low speeds the bars will pull away from you when you push on
them and at high speeds they will push back.

I believe that a moderate amount centering spring due to trail is good, as is a moderate amount due
to stem or tiller, but that neither is strictly necessary. Everyone is different - requiring
different amounts of the various kinds of feedback, but for me a bike with no trail and neither stem
nor tiller is completely and totally rideable (at least at less than escape velocity speeds).

Also, I would guess that almost everyone has ridden a bike with neither stem nor tiller. The average
3-speed upright of the 70's has a short stem and handlebars which pull back slightly. On those bikes
all the centering spring is due to trail - none of it is due to stem or tiller, and I've never met
anyone who couldn't ride one of those.

And a question for the group, don't most linked steering USS bikes have neither stem nor trail, or
perhaps precious little if any?

P.S. Remove the ratsnest to reply directly to me.

(Joseph Kochanowski) said:

Non-anecdotal data- most speedbikes like those at Battle Mountain are above seat steering.
Bicycles need something like a CENTERING SPRING. UCI approved bikes have this by having a long
stem that the rider pushes forward to center the steering. Recumbents like the Tour Easy, which is
the most popular bent where I live, centers the steering by letting the rider pull back lightly on
the handlebars.

<snip

"rorschandt" skrev

Quoted message said:

Why is it constantly necessary for some to find fault with USS? Some feel more comfortable on
USS, some don't. If YOU don't like it, let it go. Let each find his/her own way. For every
reason I read for not riding USS, I can match it with one for shunning ASS. This doesn't mean I
am going to take every opportunity on this NG to run ASS(or OSS, if you prefer) into the ground.
Ride what you like. If somebody doesn't like it, tell 'em to F.O.

Why are you being so defensive about it? Maybe I just got on this thread a bit late but I haven't
really seen anyone "run it into the ground". USS is a little slower than ASS thats all but not so
much slower that it should influence anyones choice. Safety does not seem to be an issue so what
feels best to the individual should probably be the determining factor.

Mikael

"Mikael Seierup" <[email hidden]> kirjoitti viestissä
"]news:[email hidden]... USS is a little slower than ASS thats all

Quoted message said:

but not so much slower that it should influence anyones choice. Safety does not seem to be an
issue so what feels best to the individual should probably be the determining factor.

Mikael

Slower, true , eg. 38.5 km/h with USS and 39.5 km/h with ASS at the power of 250 W. (link
m5-ligfietsen.comrecords.htmOpen ↗ )

But (the infamous but 🙂 ).

If the rolling resistance were neglible the ASS person in the above example might need about 8 %
less power to keep the same speed as the USS person (in calm weather, flat good surface, the same
weight and position, the same equipment except steering).

When riding and talking with each other 8 % might be easily observable: one is smiling, one is out
of breadth (ok, I provoke ).

"optimistx" skrev...

Quoted message said:

Slower, true , eg. 38.5 km/h with USS and 39.5 km/h with ASS at the power of 250 W. (link
m5-ligfietsen.comrecords.htmOpen ↗ )

But (the infamous but 🙂 ).

Well my point was that its too little difference to influence your choice. :-)

M.

"Mikael Seierup" <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

"rorschandt" skrev

Quoted message said:

Why is it constantly necessary for some to find fault with USS? Some feel more comfortable on
USS, some don't. If YOU don't like it, let it go. Let each find his/her own way. For every
reason I read for not riding USS, I can match it with one for shunning ASS. This doesn't mean I
am going to take every opportunity on this NG to run ASS(or OSS, if you prefer) into the
ground. Ride what you like. If somebody doesn't like it, tell 'em to F.O.

Why are you being so defensive about it? Maybe I just got on this thread a bit late but I haven't
really seen anyone "run it into the ground". USS is a little slower than ASS thats all but not so
much slower that it should influence anyones choice. Safety does not seem to be an issue so what
feels best to the individual should probably be the determining factor.

Mikael

Maybe you haven't read the "evil USS myths" a thousand times, as have I. Didn't think I was being
defensive, just stating in a different way what you said. It wouldn't be the first time that more
has been read into a statement than was intended.

Happy trails, rorschandt