Angletech Aerotrunk Speed Increase - Really?

Hi Benters, Angletech claims 2-3 mph increase. Bryan Ball Bentrideronline writes his coast down
tests show 1-1.5 mph increase. Although I high regard for Bryan and BOL, I have a hard time seeing
how this aerotrunk gives such a huge speed increase. I would like to see details of tests. At 15
mph, 1.5 mph increase is 10%. At 20 mph, 1.5 mph increase is 7.5%. Angletech's claims would result
in 20% and 15% increases. Quite frankly, I find these claims questionable. I hope you show me wrong.
~~~al.kubeluis..md.usa.earth.sun.milkyway.virgo.universe..corsa~~~

 

Al Kubeluis wrote:
>
> Hi Benters, Angletech claims 2-3 mph increase. Bryan Ball Bentrideronline writes his coast down
> tests show 1-1.5 mph increase. Although I high regard for Bryan and BOL, I have a hard time seeing
> how this aerotrunk gives such a huge speed increase. I would like to see details of tests. At 15
> mph, 1.5 mph increase is 10%. At 20 mph, 1.5 mph increase is 7.5%. Angletech's claims would result
> in 20% and 15% increases. Quite frankly, I find these claims questionable. I hope you show me
> wrong. ~~~al.kubeluis..md.usa.earth.sun.milkyway.virgo.universe..corsa~~~

The fundamental problem with Angletech's claim is it does not specify conditions. If a rider
averages 6 mph, a full hard-shell fairing is not going to increase speeds by 2-3 mph. However, put
the fairing on a very strong lowracer/rider combination that averages 25 mph unfaired, and the
average speeds may improve by 6-8 mph.

Speed increases in a fixed unit as mph are misleading, anyhow, as they will only be true for
particular power input (assuming the other variables are held constant).

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

 

Hummm, may be that placebo effect, Al, on those rear tail bags. I could have sworn the Rans Aero Bag
has increased my overall speed on my GRR Ti and Tailwind; but in reality, probably not. Maybe just
in my mind. (What little there is up there.) I guess if in your mind, you get the feeling you are
faster, than you are... Until that paceline of GO FAST Hammerhead DF'ers goes blasting past you!

I am seriously considering the Radical bag for my new Aero (Due to arrive in April. *&^%$#(* AGONY /
PAIN, withdrawals in waiting for my Aero!) and the Velcro water bottle cage from Hostel Shoppe

EZ Biker Pompano Beach, Fl. (GRR Ti, Tailwind and SOON, Bacchetta Aero Pilot)

"Al Kubeluis" <[email protected]> wrote in message
news:[email protected]...
> Hi Benters, Angletech claims 2-3 mph increase. Bryan Ball Bentrideronline writes
his
> coast down tests show 1-1.5 mph increase.

 

Well, it may have been a placebo effect for me. As soon as I put it on, the average speed on my
daily commute jumped up over 1 mph. Unfortunately, the average speed seems to be creeping back down
to normal lately (but it's been cold here lately, so that's slowing me down too). In short, I
haven't a clue on how much the Aerotrunk increases my average speed. But even if it doesn't help my
average speed much, it is still a very nice trunk. I have no problem fitting all my work
clothes/laundry, towels, a lunch, tools, extra warm gear, etc etc inside it.

Brian

Tailwind, and now a V-Rex

 

My average speed dropped suddenly about 1+ mph when the north Florida weather turned chilly (in the
50's) and headwinds became the norm. I am curious what will happen the first 75 degree day.

--
Gator Bob Siegel EasyRacers Ti Rush "bandjhughes" <[email protected]> wrote in message
news:[email protected]...
> Well, it may have been a placebo effect for me. As soon as I put it on, the average speed on my
> daily commute jumped up over 1 mph. Unfortunately, the average speed seems to be creeping back
> down to normal lately (but it's been cold here lately, so that's slowing me down too). In short, I
> haven't a clue on how much the Aerotrunk increases my average speed. But even if it doesn't help
> my average speed much, it is still a very nice trunk. I have no problem fitting all my work
> clothes/laundry, towels, a lunch, tools, extra warm gear, etc etc inside it.
>
> Brian
>
> Tailwind, and now a V-Rex

 

"Robert Siegel" <[email protected]> wrote in
news[email protected]:

> My average speed dropped suddenly about 1+ mph when the north Florida weather turned chilly (in
> the 50's) and headwinds became the norm. I am curious what will happen the first 75 degree day.
>
My average speed dropped to zero, after the Northern Indiana temperatures dropped below 45F (~:

rorschandt

 

Just to reiterate Tom's point - I think all these high speed increases
(e.g. 2-3 mph with the tail fairing trunk) are probably true - but... only at high power/velocity
outputs, that is going from 24 to 27 mph at a fixed power output but not going from 14 to 17
for a fixed power.

When I went to my t-bone from a Haluzak, I had a similar effect. My top end 2 mile time trial went
from 23 mph to 26 mph but I noticed little difference at a constant "tooling along" power of 16 mph.

Regards Chris

In article <[email protected]>, [email protected] says...
>
> Al Kubeluis wrote:
> >
> > Hi Benters, Angletech claims 2-3 mph increase. Bryan Ball Bentrideronline writes his coast down
> > tests show 1-1.5 mph increase. Although I high regard for Bryan and BOL, I have a hard time
> > seeing how this aerotrunk gives such a huge speed increase. I would like to see details of
> > tests. At 15 mph, 1.5 mph increase is 10%. At 20 mph, 1.5 mph increase is 7.5%. Angletech's
> > claims would result in 20% and 15% increases. Quite frankly, I find these claims questionable. I
> > hope you show me wrong. ~~~al.kubeluis..md.usa.earth.sun.milkyway.virgo.universe..corsa~~~
>
> The fundamental problem with Angletech's claim is it does not specify conditions. If a rider
> averages 6 mph, a full hard-shell fairing is not going to increase speeds by 2-3 mph. However, put
> the fairing on a very strong lowracer/rider combination that averages 25 mph unfaired, and the
> average speeds may improve by 6-8 mph.
>
> Speed increases in a fixed unit as mph are misleading, anyhow, as they will only be true for
> particular power input (assuming the other variables are held constant).
>
> Tom Sherman - Quad Cities USA (Illinois side) Various HPV's

 

"Chris Crawford" skrev...
> Just to reiterate Tom's point - I think all these high speed increases
> (e.g. 2-3 mph with the tail fairing trunk) are probably true - but... only at high power/velocity
> outputs, that is going from 24 to 27 mph at a fixed power output but not going from 14 to 17
> for a fixed power.

Well if the M5 lowracer only gains 3.5 kph or ~2 mph at 250W input with a hard tailfairing I find it
extremely hard to believe a 2-3 mph gain with that bag. (M5 goes from ~27 mph to 29 mph)

Mikael

 

rorschandt <[email protected]> wrote in message
news:<[email protected]>...
> "Robert Siegel" <[email protected]> wrote in
> news[email protected]:
>
> > My average speed dropped suddenly about 1+ mph when the north Florida weather turned chilly (in
> > the 50's) and headwinds became the norm. I am curious what will happen the first 75 degree day.
> >
> My average speed dropped to zero, after the Northern Indiana temperatures dropped below 45F (~:
>
> rorschandt

I have had an Aerotrunk for about four months. It really does seem to make a difference going
into strong head winds. Beyound that it holds a whole bunch of stuff. It does make a bigger
difference on my faired V2 then my other bikes. I use it on all my day trips and over nighters.
It is the best daybag I have owned. Is it worth what the current price is now.....? It is a well
made product and is a very hot item right now. I think Bentrider gave a review that reflects
what I have found it to be. I does work best with a rear rack.

 

Robert Siegel wrote:
>
> My average speed dropped suddenly about 1+ mph when the north Florida weather turned chilly (in
> the 50's) and headwinds became the norm. I am curious what will happen the first 75 degree day.

My average speed over a 15 mile section increased about 6 mph compared to the previous 15 miles on
the Bike Psycho's ride last year when the cold front came through. I was starting to feel the
effects of heat stress (headache, nausea, fatigue, disorientation) and was struggling to maintain
the 15 mph pace of my riding companions in the high heat and humidity. When the clouds blocked out
the sun and the temperature dropped almost 15 F in a matter of seconds, all my heat stress symptoms
rapidly disappeared. I put the hammer down and was riding in the mid 20 mph range on the flats and
in the upper teens on the climbs.

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

 

As pure conjecture, with no physics analysis or testing to back it up at all:

Perhaps you could realize higher gains on the bikes that bag is built for than you would with a rear
fairing on a low racer because the the lowracer is already pretty aerodynamic, whereas bikes like
mine are not nearly so. So I can at least buy that you would get a greater percentage gain over
previous speed, compared to a low-racer. As for a greater absolute gain....hmm.....well, maybe.

--
David Luecke Ridin' a RANS Vivo (wahoo!) Merritt Island, Florida USA

 

This gadget doesn't look too different in size and shape from the old Kingcycle tailbox, and that
was simply to small to have much in the way of aero effect. Useful, yes, aero, not really.

Dave Larrington - http://legslarry.crosswinds.net/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

I like the Aerotrunk, If I can add weight to my bent, become much easier to see, have the ability to
load it down with stuff when needed and, gain a little speed at the same time? Yes, I would call
that a winner! BTW, I noted a HUGE increase in average speed riding a longer loop from work today
(the weather was awesome so I added 4 miles to the ride) was it the 67F weather? A little less wind
maybe? OK, it was those two giant junkyard dogs chasing me for about a mile or so ) As the speeds
hit the mid 30's over the rough road gradually going downhill, I am happy with the full suspension
and Tioga Comp Pool front tire.

John H N TX