SWB vs Easy Racer

[Ez Biker :-\)]

In those pictures, his wheels seem to be (DUEL) 650's (?) and thus the larger wheels may really be
the PRACTICAL way to go (FAST), via the Bacchetta wheel / frame configuration? EZ Biker Pompano
Beach, Fl. (GRR Ti, Tailwind and SOON, Bacchetta Aero Pilot)

"Gabriel DeVault" <[email protected]> wrote in message
news:[email protected]...
> To anyone who doesn't know already... Steve went 62 mph in a looong streamliner at Battle Mountain
> last year (the Big Gun http://www.easyracers.com/images/PICT0701.jpg). He also won the Cherry Pie
> Criterium last year in his looong faired Rotator Pursuit
> (http://www.easyracers.com/images/DSC01204.jpg). He may be afraid to toot his own horn... but I
> think Steve is on to something. In talking to Matt Weaver, he says that this is one of the
> "branches" in aerodynamic theory. Least surface/frontal area or ideal shape? It only gets more
complicated...
>
>
>
> "S. Delaire "Rotatorrecumbent"" <[email protected]> wrote in message
> news:[email protected]...
> > From the perspective of some one who builds both styles: To speak about the speed, first let me
> > say I have several different
tests
> > and test equipment for my bikes. One is a coast down test on a .8 mile long road. Test two is a
> > climb test on the same hill using a Powertap
hub
> > ( max watts and average watts) with heart rate monitor. Test three is a half hour of laps in
> > local high school parking lot that has some slope
to
> > it i.e. every lap goes up and down. Last test is the 65 mph test. Some of what I've found defies
> > logic. My only criteria is speed. All
tests
> > are done by me with no back up numbers from other riders. The Tiger model (swb) has the smallest
> > frontal area with a higher crank. The Pursuit model (lwb) has lower cranks and more frontal
> > area. Yet it is the Pursuit that tests fastest in all tests which is puzzling. Almost all other
> > brands and types of recumbents as well as a few
uprights
> > have been tested on the same courses with similar results. My conclusion is that for speed,
> > longer is better. Longer also is helpful for
stability
> > at high speed. (65 mph test) Don't get me wrong short bikes are wonderful for many reasons
> > but if
your
> > only criteria is speed... Happy cycling Steve "Speedy" Delaire
> >
> >
> > David Cambon wrote:
> >
> > > Short Wheel-Base vs Easy Racer
> > >
> > > Sorry for bringing this topic up again but I have seen a lot of discussion on this newsgroup
> > > that is not all that clear. For the sake of newbies a few things should be clarified by you
> > > level-headed and objective scientific types who read this list.
> > >
> > > By SWB I mean all the highracers (eg Bacchetta Aero, Vision Saber etc) and all the
> > > non-lowracer SWB's with the smaller front wheel (eg Burley HepCat, Lightning P-38, Rans V-Rex,
> > > Turner T-Lite, Bachetta Giro, TerraCycle Terraza, Vision R40, Angletech etc).
> > >
> > > By Easy Racer I mean the Tour Easy, GRR, TiGRR and all clones of that configuration made by
> > > other people.
> > >
> > > There has been a lot of foaming-at-the-mouth, drooling and just plain ga-ga over the new crop
> > > of Bacchettas. I want one too so don't start flaming me just yet. That Bacchetta mesh seat is
> > > more comfortable than my furniture at home. I love those bars too. However, the basic idea is
> > > not new. Just go to Europe and have a look for yourself. The Bacchetta Aero even comes with
> > > Bram Moens seat from the Netherlands.
> > >
> > > The problem I have is the people on this list who are running out and buying a Bacchetta (or
> > > its ilk) based on completely unscientific observations that have been posted on this group. I
> > > wouldn't toss your TiGRR onto the composter based on what you have seen here.
> > >
> > > You can't just go and try out a couple of bikes and declare one unequivocally faster based on
> > > your "feelings" or even a trip around your test loop. There are many factors that determine
> > > the speed of a bicycle. Yes, one factor is the coefficient of drag. Another factor is the
> > > cyclist! SWB's and LWB's use different positions and physiological attributes. Each position
> > > takes time to acclimate to. Some people apparently don't acclimate to sky-high bottom-brackets
> > > (I like the HepCat, for instance, because it has a lower bottom-bracket).
> > >
> > > I now submit myself for a manly third-degree flaming by saying this: some of you fat old guys
> > > ride differently than skinny superathletes. A super-fit thin guy with no real job can make
> > > different bikes go fast than a pasty-faced outta-shape desk jockey. There is also the issue of
> > > real-world cycling conditions. Most people do not ride at a steady pace of 25mph (as some of
> > > the people on this group seem to be doing). Most people actually ride slower - where wind
> > > resistance is much less important.
> > >
> > > Here's my 2 cents worth: I ride all types of bikes. My preference around here (in the Coast
> > > Mountains of British Columbia) is a LWB because of the high-speed descents where it possible
> > > to hit tremendous speeds for long periods of time (eg speed-trapped at 126kph). The LWB just
> > > feels better than any SWB at speed. I am acclimated to both SWB's and LWB's. I am a strong,
> > > fast rider who weighs 225 pounds and I drop like a stone on descents. On flat ground riding
> > > all day I am faster on an unfaired LWB than I am on a SWB. The explanation is not obvious. The
> > > LWB (a Recumbonie) is undoubtedly more laterally flexy than a Tour Easy GRR and heavier too.
> > > However, the seat is lower so it could be slightly more aerodynamically efficient (but I doubt
> > > that really makes any difference). I also prefer the lower LWB pedals in stop-and-go city
> > > traffic. On the other hand, many SWB's fit into transit bus racks (which the transit buses
> > > have around here).
> > >
> > > I'd do a more scientific test with an Easy Racer but they are not readily available in this
> > > part of the world.
> > >
> > > Anyway, c'mon smarty-people, get your responses in!
> >
> >
> >
> > -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1
> > Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =-----

 

[S. Delaire \"Ro]

In the case of the "Big Gun" the wheel size is 700c and choice was made based on availability of
high quality tires. Bike that won the road race is a standard Pursuit with 451 wheel size, IRC
Roadlite tires. Another interesting thing from the coast down tests that defied logic. Two bikes,
both Pursuits one has 700c wheels the other 451 Same brand and model tire on all wheels Coast down
hill three times each. After the end of 6 total runs there was only 1 second difference between both
bikes, basically the same results for total time during the run, BUT, the small wheel bike had a 1.5
mph higher peak speed every run. This is the first time in using this hill that I wished it was
bowled shaped so the bike would have to roll back up the other side. The suggestions of the computer
print out from the runs lead me to believe that the big wheel bike would coast further in the lower
speed range but the little wheel bike gets up to speed better.

Note: "Big Gun" is surfer slang for a long board.

Happy cycling Steve "Speedy" Delaire

"EZ Biker " wrote:

> In those pictures, his wheels seem to be (DUEL) 650's (?) and thus the larger wheels may really be
> the PRACTICAL way to go (FAST), via the Bacchetta wheel / frame configuration? EZ Biker
> Pompano Beach, Fl. (GRR Ti, Tailwind and SOON, Bacchetta Aero Pilot)
>
> "Gabriel DeVault" <[email protected]> wrote in message
> news:[email protected]...
> > To anyone who doesn't know already... Steve went 62 mph in a looong streamliner at Battle
> > Mountain last year (the Big Gun http://www.easyracers.com/images/PICT0701.jpg). He also won the
> > Cherry Pie Criterium last year in his looong faired Rotator Pursuit
> > (http://www.easyracers.com/images/DSC01204.jpg). He may be afraid to toot his own horn... but I
> > think Steve is on to something. In talking to Matt Weaver, he says that this is one of the
> > "branches" in aerodynamic theory. Least surface/frontal area or ideal shape? It only gets more
> complicated...
> >
> >
> >
> > "S. Delaire "Rotatorrecumbent"" <[email protected]> wrote in message
> > news:[email protected]...
> > > From the perspective of some one who builds both styles: To speak about the speed, first let
> > > me say I have several different
> tests
> > > and test equipment for my bikes. One is a coast down test on a .8 mile long road. Test two is
> > > a climb test on the same hill using a Powertap
> hub
> > > ( max watts and average watts) with heart rate monitor. Test three is a half hour of laps in
> > > local high school parking lot that has some slope
> to
> > > it i.e. every lap goes up and down. Last test is the 65 mph test. Some of what I've found
> > > defies logic. My only criteria is speed. All
> tests
> > > are done by me with no back up numbers from other riders. The Tiger model (swb) has the
> > > smallest frontal area with a higher crank. The Pursuit model (lwb) has lower cranks and more
> > > frontal area. Yet it is the Pursuit that tests fastest in all tests which is puzzling. Almost
> > > all other brands and types of recumbents as well as a few
> uprights
> > > have been tested on the same courses with similar results. My conclusion is that for speed,
> > > longer is better. Longer also is helpful for
> stability
> > > at high speed. (65 mph test) Don't get me wrong short bikes are wonderful for many reasons
> > > but if
> your
> > > only criteria is speed... Happy cycling Steve "Speedy" Delaire
> > >
> > >
> > > David Cambon wrote:
> > >
> > > > Short Wheel-Base vs Easy Racer
> > > >
> > > > Sorry for bringing this topic up again but I have seen a lot of discussion on this newsgroup
> > > > that is not all that clear. For the sake of newbies a few things should be clarified by you
> > > > level-headed and objective scientific types who read this list.
> > > >
> > > > By SWB I mean all the highracers (eg Bacchetta Aero, Vision Saber etc) and all the
> > > > non-lowracer SWB's with the smaller front wheel (eg Burley HepCat, Lightning P-38, Rans
> > > > V-Rex, Turner T-Lite, Bachetta Giro, TerraCycle Terraza, Vision R40, Angletech etc).
> > > >
> > > > By Easy Racer I mean the Tour Easy, GRR, TiGRR and all clones of that configuration made by
> > > > other people.
> > > >
> > > > There has been a lot of foaming-at-the-mouth, drooling and just plain ga-ga over the new
> > > > crop of Bacchettas. I want one too so don't start flaming me just yet. That Bacchetta mesh
> > > > seat is more comfortable than my furniture at home. I love those bars too. However, the
> > > > basic idea is not new. Just go to Europe and have a look for yourself. The Bacchetta Aero
> > > > even comes with Bram Moens seat from the Netherlands.
> > > >
> > > > The problem I have is the people on this list who are running out and buying a Bacchetta (or
> > > > its ilk) based on completely unscientific observations that have been posted on this group.
> > > > I wouldn't toss your TiGRR onto the composter based on what you have seen here.
> > > >
> > > > You can't just go and try out a couple of bikes and declare one unequivocally faster based
> > > > on your "feelings" or even a trip around your test loop. There are many factors that
> > > > determine the speed of a bicycle. Yes, one factor is the coefficient of drag. Another factor
> > > > is the cyclist! SWB's and LWB's use different positions and physiological attributes. Each
> > > > position takes time to acclimate to. Some people apparently don't acclimate to sky-high
> > > > bottom-brackets (I like the HepCat, for instance, because it has a lower bottom-bracket).
> > > >
> > > > I now submit myself for a manly third-degree flaming by saying this: some of you fat old
> > > > guys ride differently than skinny superathletes. A super-fit thin guy with no real job can
> > > > make different bikes go fast than a pasty-faced outta-shape desk jockey. There is also the
> > > > issue of real-world cycling conditions. Most people do not ride at a steady pace of 25mph
> > > > (as some of the people on this group seem to be doing). Most people actually ride slower -
> > > > where wind resistance is much less important.
> > > >
> > > > Here's my 2 cents worth: I ride all types of bikes. My preference around here (in the Coast
> > > > Mountains of British Columbia) is a LWB because of the high-speed descents where it possible
> > > > to hit tremendous speeds for long periods of time (eg speed-trapped at 126kph). The LWB just
> > > > feels better than any SWB at speed. I am acclimated to both SWB's and LWB's. I am a strong,
> > > > fast rider who weighs 225 pounds and I drop like a stone on descents. On flat ground riding
> > > > all day I am faster on an unfaired LWB than I am on a SWB. The explanation is not obvious.
> > > > The LWB (a Recumbonie) is undoubtedly more laterally flexy than a Tour Easy GRR and heavier
> > > > too. However, the seat is lower so it could be slightly more aerodynamically efficient (but
> > > > I doubt that really makes any difference). I also prefer the lower LWB pedals in stop-and-go
> > > > city traffic. On the other hand, many SWB's fit into transit bus racks (which the transit
> > > > buses have around here).
> > > >
> > > > I'd do a more scientific test with an Easy Racer but they are not readily available in this
> > > > part of the world.
> > > >
> > > > Anyway, c'mon smarty-people, get your responses in!
> > >
> > >
> > >
> > > -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The
> > > #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers!
> > > =-----
> >
> >

-----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1
Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =-----

 

[Chris Crawford]

Speedy - thanks for the data. It's nice to something more or less "scientific" and "evidence based"
on the newsgroup. I've always wanted a powertap to run my own experiments. There is too much
anecdotal "feeling" that goes into analysis in the NG.

Regards Chris

In article <[email protected]>, "S. Delaire \"Rotatorrecumbent\""
<[email protected]> says...
> In the case of the "Big Gun" the wheel size is 700c and choice was made based on availability of
> high quality tires. Bike that won the road race is a standard Pursuit with 451 wheel size, IRC
> Roadlite tires. Another interesting thing from the coast down tests that defied logic. Two bikes,
> both Pursuits one has 700c wheels the other 451 Same brand and model tire on all wheels Coast down
> hill three times each. After the end of 6 total runs there was only 1 second difference between
> both bikes, basically the same results for total time during the run, BUT, the small wheel bike
> had a 1.5 mph higher peak speed every run. This is the first time in using this hill that I wished
> it was bowled shaped so the bike would have to roll back up the other side. The suggestions of the
> computer print out from the runs lead me to believe that the big wheel bike would coast further in
> the lower speed range but the little wheel bike gets up to speed better.
>
> Note: "Big Gun" is surfer slang for a long board.
>
> Happy cycling Steve "Speedy" Delaire
>
>
>
>
> "EZ Biker " wrote:
>
> > In those pictures, his wheels seem to be (DUEL) 650's (?) and thus the larger wheels may really
> > be the PRACTICAL way to go (FAST), via the Bacchetta wheel / frame configuration? EZ Biker
> > Pompano Beach, Fl. (GRR Ti, Tailwind and SOON, Bacchetta Aero Pilot)
> >
> > "Gabriel DeVault" <[email protected]> wrote in message
> > news:[email protected]...
> > > To anyone who doesn't know already... Steve went 62 mph in a looong streamliner at Battle
> > > Mountain last year (the Big Gun http://www.easyracers.com/images/PICT0701.jpg). He also won
> > > the Cherry Pie Criterium last year in his looong faired Rotator Pursuit
> > > (http://www.easyracers.com/images/DSC01204.jpg). He may be afraid to toot his own horn... but
> > > I think Steve is on to something. In talking to Matt Weaver, he says that this is one of the
> > > "branches" in aerodynamic theory. Least surface/frontal area or ideal shape? It only gets more
> > complicated...
> > >
> > >
> > >
> > > "S. Delaire "Rotatorrecumbent"" <[email protected]> wrote in message
> > > news:[email protected]...
> > > > From the perspective of some one who builds both styles:

 

[David Cambon]

Excellent responses people!

So far:

- In the excitement, a cat may, or may not, have jumped on a keyboard.

- Gator Bob made an emotional and heartfelt conciliatory gesture toward Cletus.

- Steve Delaire (Rotator) posted some interesting test results that indicate LWB's can be faster
than SWB's even though LWB's have a larger frontal area. The conventional wisdom may have to be
altered to explain such a finding.

- "me" at citycom made an interesting point about the hydrodynamic qualities of long boat hulls.
This is the kind of brainstorming idea that may lead to other ideas. Allen on AOL and Gabriel
DeVault (Easy Racers) discussed the notion that bike length may be more important to bike speed
than we think. Apparently there may be a branch of aerodynamic theory to address this topic.
Perhaps some type of ground effect may be responsible.

- Mark Stonich made in interesting point about the interaction of handlebar reach, trail/wheelflop
and "control spring".

- Bob Bryant (Recumbent Cyclist News) reminded us of the timeless beauty of the Easy Racer type of
bike. I know there are many others who have a long-term love-affair with the Easy Racer. America
is the land of technological innovation and material wealth. Citizens of the United States count
yourself fortunate to have family-size boxes of Lucky Charms, spray-bottle margarine and the Tour
Easy, for these luxuries are not so readily available elsewhere.

- Bob Larrington (British Human Power Club Newsletter) pointed out just how uniquely American Easy
Racers are. I must concur. Perhaps it is the high value of the US dollar, the storage requirements
of the Easy Racer or maybe the distribution network for the bike. It could be the proliferation of
interesting Euro-bents. I recently saw an interesting one sitting in a train station
(Velo-Werktatt Solothurn fateba Switzerland). I have never seen a similar bike in the US.

- It was pointed out (and this cannot be repeated too many times) that sometimes it is nice to
have a SWB because they fit into the same space as a diamond frame upright bike. There are times
when I ride a SWB for that reason alone. However, under most circumstances I prefer the
luxurious ride of a LWB.

- On an adjacent topic posted on this group there is a discussion of fairings. Fairings seem to work
best on LWB's. I would like to have a fairing (eg Tour Easy Zzipper fairing) for weather
protection. I don't really care if it makes me (allegedly) an increment faster. I am not using my
recumbent in the Tour de France and to be honest, I am not getting enough exercise from my
recumbents anyway. They are more energy-efficient than my upright bikes and go too fast as it is.

- There have been suggestions that LWB's are slow and unstable going uphill. I have never had that
experience. I presume that as long as the lateral deflection of the frame produced during the
pedal stroke is returned as forward motion to the same degree it is on a SWB then an LWB of equal
weight should go uphill at the same rate using the same amount of energy. Perhaps the drive side
chain idlers on some SWB's convert pedaling energy into non-productive vertical flex.

- I would like to hear of some more experiences with the Puncture Fairy and the front wheel.

 

[Robert Siegel]

I found the RANS V2 to be a very difficult ride up a steep hill, especially at low speed.

--
Gator Bob Siegel EasyRacers Ti Rush

"David Cambon" <[email protected]> wrote > - There have been suggestions that LWB's
are slow and unstable going uphill. I have never had that experience.

 

[Just Zis Guy]

On 7 Feb 2003 12:47:54 -0800, [email protected] (David Cambon) wrote:

>- Dave Larrington (British Human Power Club Newsletter) pointed out just how uniquely American Easy
> Racers are.

Having heard Dave mention that there are very few LWB bents in the UK, the very same afternoon I was
surfing past my bike shop and saw this: <http://www.futurecycles.co.uk/tuitionhire.html> - made me
smile, anyway

Guy
===
** WARNING ** This posting may contain traces of irony. http://www.chapmancentral.com (BT ADSL and
dynamic DNS permitting)
NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer
work. Apologies.

 

[Tom Sherman]

"S. Delaire \"Rotatorrecumbent\"" wrote:
> ... Another interesting thing from the coast down tests that defied logic. Two bikes, both
> Pursuits one has 700c wheels the other 451 Same brand and model tire on all wheels Coast down hill
> three times each. After the end of 6 total runs there was only 1 second difference between both
> bikes, basically the same results for total time during the run, BUT, the small wheel bike had a
> 1.5 mph higher peak speed every run....

Steve,

I suspect what is happening here is the Pursuit with the ISO 622-mm wheels [1] has lower rolling
resistance so it gains speed more rapidly than the Pursuit with ISO 451-mm wheels at the start.
However, if the Pursuit with the ISO 451-mm wheels is more aerodynamic, it will gain speed more
rapidly after the point where its lower drag compensates for the higher rolling resistance. Since
the larger wheel Pursuit had an early lead, the times will be the same, but the smaller wheel
Pursuit will have a greater peak speed. [2] Therefore the big wheel Pursuit should be faster on a
hilly course where more time is spent at low speeds climbing, while the small wheel Pursuit should
have the advantage on a flat or windy course.

[1] 700C for traditionalists.
[2] Matt Weaver and others have posted ways of back-calculating coefficient of drag {Cd) and
coefficient of rolling resistance {Crr) from coast down data on the "Streamliner" mailing list.

Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Bentbiker]

you know Tom, some people take "shots" at your comments, this post was very interesting and well
thought out. Don't get a swollen noggin now

Tom Sherman wrote:
> "S. Delaire \"Rotatorrecumbent\"" wrote:
>
>>... Another interesting thing from the coast down tests that defied logic. Two bikes, both
>>Pursuits one has 700c wheels the other 451 Same brand and model tire on all wheels Coast down hill
>>three times each. After the end of 6 total runs there was only 1 second difference between both
>>bikes, basically the same results for total time during the run, BUT, the small wheel bike had a
>>1.5 mph higher peak speed every run....
>
>
> Steve,
>
> I suspect what is happening here is the Pursuit with the ISO 622-mm wheels [1] has lower rolling
> resistance so it gains speed more rapidly than the Pursuit with ISO 451-mm wheels at the start.
> However, if the Pursuit with the ISO 451-mm wheels is more aerodynamic, it will gain speed more
> rapidly after the point where its lower drag compensates for the higher rolling resistance. Since
> the larger wheel Pursuit had an early lead, the times will be the same, but the smaller wheel
> Pursuit will have a greater peak speed. [2] Therefore the big wheel Pursuit should be faster on a
> hilly course where more time is spent at low speeds climbing, while the small wheel Pursuit should
> have the advantage on a flat or windy course.
>
> [1] 700C for traditionalists.
> [2] Matt Weaver and others have posted ways of back-calculating coefficient of drag {Cd) and
> coefficient of rolling resistance {Crr) from coast down data on the "Streamliner" mailing
> list.
>
> Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[A&B]

S., This is the same thing I tend to notice when coasting on my Aero with Rev Hodges on his Pursuit.
It's like we are "faster" at different speeds. bill g

"S. Delaire \"Rotatorrecumbent\"" wrote: The suggestions of the
> computer print out from the runs lead me to believe that the big wheel bike would coast further in
> the lower speed range but the little wheel bike gets up to speed better.

 

[Jeff Wills]

John Foltz <[email protected]> wrote in message news:<[email protected]>...
> Cletus Lee wrote:
> > In article <[email protected]>, [email protected] says...
> >
> >>It depends on the SWB. I've had my P-38 close to 60 without any issues beyond my cheeks going
> >>whuppa-whuppa-whuppa.
> >
> > Which cheeks?
>
> He must not have been grinning hard enough if his facial cheeks were flapping in the wind. I won't
> comment if he was speaking of the 'other' cheeks. ;-)

Geez, can't sneak past you guys for nothin'. I was speaking of the face cheeks, as John says. The
other cheeks, well, they were workin' pretty hard spinning the pedals at 140 rpm.

Jeff

 

[Jeff Wills]

[email protected] (David Cambon) wrote in message
news:<[email protected]>...
> - I would like to hear of some more experiences with the Puncture Fairy and the front wheel.

See the thread "I have angered the Flat Gods!". Then, carry extra patch kits.

Jeff

 

[Tom Sherman]

"S. Delaire \"Rotatorrecumbent\"" wrote:
>
> In the case of the "Big Gun" the wheel size is 700c and choice was made based on availability of
> high quality tires....

A couple things that should be mentioned about the "Big Gun" was that it was only bike competing in
the top speed trials at the 2002 WHPSC [1] that did not have a canopy. In addition, the "Big Gun"
appears to almost be able to be ridden on the street [2], which can not be said about any of the
other competitor with the exception of Warren Beauchamp's Barracuda. In this context, the 62 mph
(100 kph) speed attained is VERY impressive.

[1]http://www.wisil.recumbents.com/wisil/whpsc2002/speedchallenge-2002.htm
[2] Maybe Steve Delaire will comment on crosswind stability.

Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Tom Sherman]

a&b wrote:
>
> S., This is the same thing I tend to notice when coasting on my Aero with Rev Hodges on his
> Pursuit. It's like we are "faster" at different speeds.

When riding my RANS Rocket, I am able to out-coast a riding companion on a front faired TiGRR from a
near stop up to about 15 mph (~25 kph), but the TiGRR gains speed more rapidly after that. I believe
that this is due to my gross weight being about 30 lbs. (~13 1/2 kgf) greater but my having a
greater CdA. [1]

[1] Coefficient of drag multiplied by frontal area.

Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Harv]

You're slipping Tom. Mach .5? Isn't that in the 350mph range? "Tom Sherman" <[email protected]>
wrote in message news:[email protected]...
>
> Mark Stonich wrote:
> >
>
snip

> I find the RANS Rocket (which has a reputation among some for being twitchy) to be very similar to
> the P-38 in this regard. It should be noted that I have the 1999-2000 frameset [1] with the
> shorter chainstays, I am tall enough (45"/114 cm x-seam) to have the seat fairly far back [2], the
> Flip-It is adjusted for moderate tiller, and the P-38 that I have ridden is an XL size. Speeds in
> the 40-50 mph (65-80 kph/ .54-0.67 Mach) [5] do not feel particularly fast in terms of bike
> handling.
>
snip

> Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Von]

[email protected] (David Cambon) wrote in message
news:<[email protected]>...
> Short Wheel-Base vs Easy Racer
>
> Sorry for bringing this topic up again but I have seen a lot of discussion on this newsgroup that
> is not all that clear. For the sake of newbies a few things should be clarified by you
> level-headed and objective scientific types who read this list.
>
> By SWB I mean all the highracers (eg Bacchetta Aero, Vision Saber etc) and all the non-lowracer
> SWB's with the smaller front wheel (eg Burley HepCat, Lightning P-38, Rans V-Rex, Turner T-Lite,
> Bachetta Giro, TerraCycle Terraza, Vision R40, Angletech etc).
>
> By Easy Racer I mean the Tour Easy, GRR, TiGRR and all clones of that configuration made by
> other people.
>
> There has been a lot of foaming-at-the-mouth, drooling and just plain ga-ga over the new crop of
> Bacchettas. I want one too so don't start flaming me just yet. That Bacchetta mesh seat is more
> comfortable than my furniture at home. I love those bars too. However, the basic idea is not new.
> Just go to Europe and have a look for yourself. The Bacchetta Aero even comes with Bram Moens seat
> from the Netherlands.
>
> The problem I have is the people on this list who are running out and buying a Bacchetta (or its
> ilk) based on completely unscientific observations that have been posted on this group. I wouldn't
> toss your TiGRR onto the composter based on what you have seen here.
>
> You can't just go and try out a couple of bikes and declare one unequivocally faster based on your
> "feelings" or even a trip around your test loop. There are many factors that determine the speed
> of a bicycle. Yes, one factor is the coefficient of drag. Another factor is the cyclist! SWB's and
> LWB's use different positions and physiological attributes. Each position takes time to acclimate
> to. Some people apparently don't acclimate to sky-high bottom-brackets (I like the HepCat, for
> instance, because it has a lower bottom-bracket).
>
> I now submit myself for a manly third-degree flaming by saying this: some of you fat old guys ride
> differently than skinny superathletes. A super-fit thin guy with no real job can make different
> bikes go fast than a pasty-faced outta-shape desk jockey. There is also the issue of real-world
> cycling conditions. Most people do not ride at a steady pace of 25mph (as some of the people on
> this group seem to be doing). Most people actually ride slower - where wind resistance is much
> less important.
>
> Here's my 2 cents worth: I ride all types of bikes. My preference around here (in the Coast
> Mountains of British Columbia) is a LWB because of the high-speed descents where it possible to
> hit tremendous speeds for long periods of time (eg speed-trapped at 126kph). The LWB just feels
> better than any SWB at speed. I am acclimated to both SWB's and LWB's. I am a strong, fast rider
> who weighs 225 pounds and I drop like a stone on descents. On flat ground riding all day I am
> faster on an unfaired LWB than I am on a SWB. The explanation is not obvious. The LWB (a
> Recumbonie) is undoubtedly more laterally flexy than a Tour Easy GRR and heavier too. However, the
> seat is lower so it could be slightly more aerodynamically efficient (but I doubt that really
> makes any difference). I also prefer the lower LWB pedals in stop-and-go city traffic. On the
> other hand, many SWB's fit into transit bus racks (which the transit buses have around here).
>
> I'd do a more scientific test with an Easy Racer but they are not readily available in this part
> of the world.
>
> Anyway, c'mon smarty-people, get your responses in!

I can only compare,swb,lwb between a Tandem (Screamer) and (V-REX)on a down hill at speed. The same
with DF (Santana Sovereign GT) and (Pianrello Monviso). Longer wheel base is more stable at speed
on a well made bike undamaged frame.126 kph! I though I was fast at 97 kph. Hope your roads are
smoother than ours in Western MA. (its not what you ride,but that you ride) Von

 

[Tom Sherman]

"EZ Biker " wrote:
>
> In those pictures, his wheels seem to be (DUEL) 650's...

EZ,

What is with these bikes that have the wheels fighting each other?

I believe the Rotator "Big Gun" has DUAL ISO 622-mm (700C) wheels.

Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Tom Sherman]

harv wrote:
>
> You're slipping Tom. Mach .5? Isn't that in the 350mph range?

Harv,

I didn't slip, but the decimal points did.

Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Ez Biker :-\)]

I don't know Tom! Maybe some "dueling" wheels might help me to go faster... <Grin> (Hey I can't
spell worth a FLIP, much less even roll somewhat fast on a bike! ;-) <Grin> By the way, I really do
LIKE your COCOON-WIND! I enjoy my "Regular Wind", especially with the Conti's I recently put on, in
place of the Hookworms and the added fairing. And YES, you are correct about the Rotator wheels
being DUAL 700cc's. Makes me wonder if the Rotator people are moving away from the DUAL 20 inch
wheel setup, and following the path of other BIG DUAL Wheel recumbo manufacturers. Vision,
Bacchetta? EZ Biker Pompano Beach, Fl. (GRR Ti, Tailwind and SOON, Bacchetta Aero Pilot)

"Tom Sherman" <[email protected]> wrote in message news:[email protected]...
>
> "EZ Biker " wrote:
> >
> > In those pictures, his wheels seem to be (DUEL) 650's...
>
> EZ,
>
> What is with these bikes that have the wheels fighting each other?
>
> I believe the Rotator "Big Gun" has DUAL ISO 622-mm (700C) wheels.
>
> Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

[Mark Stonich]

"S. Delaire \"Rotatorrecumbent\"" <[email protected]> wrote > Another interesting thing from the
coast down tests that defied logic.
> Two bikes, both Pursuits one has 700c wheels the other 451 Same brand and model tire on all
> wheels Coast down hill three times each. After the end of 6 total runs there was only 1 second
> difference between both bikes, basically the same results for total time during the run, BUT, the
> small wheel bike had a 1.5 mph higher peak speed every run. This is the first time in using this
> hill that I wished it was bowled shaped so the bike would have to roll back up the other side.
> The suggestions of the computer print out from the runs lead me to believe that the big wheel
> bike would coast further in the lower speed range but the little wheel bike gets up to speed
> better. Steve "Speedy" Delaire

Steve, This is consistant with what I discovered doing rolldown tests between fat and narrow tires
back in my wedgie days.

Rolling and mechanical resistance increase roughly linearly with the increase in speed. Aero
resistance increases with the square of the increase in speed. In the case of tires this is more of
a factor since the top of the tire is going twice as fast as the rest of the bike.

A wider or taller tire usually has lower total resistance at low speeds. However, as speeds
increase, aero drag becomes a higher percentage of the total resistance. There will be some
velocity at which the total drag of the larger tire becomes higher.

In my test, the hill had a gradual slope at the top, increasing to about 10%, with a long flat
runnout at the bottom. Every time the bike with easier rolling fatties (26 x 1.625" Schwinn
MidTowners IMHO one of the easiest rolling tires ever made, very flat profile) would take a lead at
the top of the hill, as speeds increased the narrow tired (700x23 Michelins) bike would pass, and
hold a lead till speeds decreased, when the other bike would pass and roll quite a way further
before stopping.

The bike's riding positions were similar, and switching riders made little difference. In this
particular case the narrower tires seemed to have an advantage above 18-20 mph. Since I don't spend
much time above 18 mph anymore, I select my tires for RR, not aero drag.

 

[Bill Patterson]

I think that the "power absorbed" (is that a technical term?) increases linearly for rolling
resistance. It increases as the cube of aerodynamic drag. That's why aero stuff is so important for
going fast.
--
Bill "Pop Pop" Patterson Retired and riding my Linear, my front drive low racer and our M5 tandem.