How many pounds of thrust to keep a bike moving?

[Bruce W.1]

I was thinking of putting a small turbine engine on my road bicycle,
just for grins. How many pounds of thrust do you think would be needed
to maintain 20 mph?

There's a bunch of tiny jet engines for RC airplanes with from 10 to 50
lbs of thrust. Here's one:
http://www.franktiano.com/t-750.htm

Here's a video of the mother of all RC airplanes:
http://www.mcgirt.net/RC/VIDEOS/Giant_B52/B52_flight2.wmv

 

[JeffWills]

Bruce W.1 wrote:
> I was thinking of putting a small turbine engine on my road bicycle,
> just for grins. How many pounds of thrust do you think would be
needed
> to maintain 20 mph?
>
> There's a bunch of tiny jet engines for RC airplanes with from 10 to
50
> lbs of thrust. Here's one:
> http://www.franktiano.com/t-750.htm
>
> Here's a video of the mother of all RC airplanes:
> http://www.mcgirt.net/RC/VIDEOS/Giant_B52/B52_flight2.wmv

It's been done. Vision Recumbents put a 15 pound thrust engine on the
back of one of their bikes, and it pushed the bike to 30 mph. Loud
mother, too. Pictures and movies of it in action here:
http://www.outsideconnection.com/gallant/hpv/vision/

Jeff

 

[Jim Smith]

"Bruce W.1" <[email protected]> writes:

> I was thinking of putting a small turbine engine on my road bicycle,
> just for grins. How many pounds of thrust do you think would be
> needed to maintain 20 mph?

About 5 lbsf.

> There's a bunch of tiny jet engines for RC airplanes with from 10 to
> 50 lbs of thrust. Here's one:
> http://www.franktiano.com/t-750.htm

That one has 95N thrust. At 10m/s (22mph) that is 950 watts, quite a
bit more than any cyclist. Your duty is clear.

http://members.aye.net/~gharris/blog/shopmod07.jpg

 

[Mike Jacoubowsky]

> It's been done. Vision Recumbents put a 15 pound thrust engine on the
> back of one of their bikes, and it pushed the bike to 30 mph. Loud
> mother, too. Pictures and movies of it in action here:
> http://www.outsideconnection.com/gallant/hpv/vision/
>
> Jeff

My vote for best link of the day. Week. Month. Maybe year. This is better
than hamsterdance.com or whatever it is.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

 

[[email protected]]

On Wed, 04 May 2005 22:57:22 GMT, "Bruce W.1"
<[email protected]> wrote:

>I was thinking of putting a small turbine engine on my road bicycle,
>just for grins. How many pounds of thrust do you think would be needed
>to maintain 20 mph?
>
>There's a bunch of tiny jet engines for RC airplanes with from 10 to 50
>lbs of thrust. Here's one:
>http://www.franktiano.com/t-750.htm
>
>Here's a video of the mother of all RC airplanes:
>http://www.mcgirt.net/RC/VIDEOS/Giant_B52/B52_flight2.wmv

Dear Bruce,

At $2795 plus shipping plus tax plus earmuffs plus public
nuisance fine plus fuel at 11 ounces per minute, it will be
an expensive grin.

Slightly off-topic, but why do they come up with 24 pounds
as equal to 95 newtons? Everywhere that I looked, 95 newtons
converts to about 21.36 pounds (9% lower than the claimed 24
pounds), while 5 newtons ends up as 1.124 pounds (12% higher
than the claimed 1.0 pounds).

http://www.onlineconversion.com/weight_all.htm

Are they using troy newtons, imperial pounds, nautical
thrust, or what? Am I just missing something obvious?

Persnicketily,

Carl Fogel

 

[Leo Lichtman]

"Bruce W.1" wrote" (clip) How many pounds of thrust do you think would be
needed to maintain 20 mph? (clip)
^^^^^^^^^^^^^^^
I assumed that 1/4 HP would do it. That's 550/4=137.5 ft lb/sec. 20 MPH =
29 ft/sec. Power = force x velocity, so the force comes out 137.5/29= under
5 lb thrust. A rider developing 1/4 HP has to provide the power train
losses, which the jet engine bypasses. OTOH, my figure of 1/4 HP is just a
wild-ass guess. I imagine there must be SOME combination of rider, bike,
clothing, riding position, etc, that would consume about that amount of
power at about that speed.

 

[Werehatrack]

On Wed, 04 May 2005 22:57:22 GMT, "Bruce W.1"
<[email protected]> wrote:

>I was thinking of putting a small turbine engine on my road bicycle,
>just for grins. How many pounds of thrust do you think would be needed
>to maintain 20 mph?
>
>There's a bunch of tiny jet engines for RC airplanes with from 10 to 50
>lbs of thrust. Here's one:
>http://www.franktiano.com/t-750.htm
>
>Here's a video of the mother of all RC airplanes:
>http://www.mcgirt.net/RC/VIDEOS/Giant_B52/B52_flight2.wmv

Real jet-powered vehicle experimenters build their *own* engines.

http://www.aardvark.co.nz/pjet/

And a gas turbine is useful for more than just generating thrust; it
can also cool your beer while making painful amounts of noise!

http://www.asciimation.co.nz/beer/


--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Mark Hickey]

"Bruce W.1" <[email protected]> wrote:

>I was thinking of putting a small turbine engine on my road bicycle,
>just for grins. How many pounds of thrust do you think would be needed
>to maintain 20 mph?

I'm not sure, but I know it takes a lot more thrust that you get from
a medium-size leaf blower (gas powered). I expected to be pushed to
at least 5-6mph (8-10km/h) but alas, it barely moved me at all. All
noise, no thrust.

Now all I am left to do with it is to blow leaves. Harumph.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

 

[meb]

Bruce W.1 wrote:
> I was thinking of putting a small turbine engine on my road bicycle,
> just for grins. How many pounds of thrust do you think would be
needed
> to maintain 20 mph?
>
> There's a bunch of tiny jet engines for RC airplanes with from 10 to
50
> lbs of thrust. Here's one:
> http://www.franktiano.com/t-750.htm
>
> Here's a video of the mother of all RC airplanes:
> http://www.mcgirt.net/RC/VIDEOS/Giant_B52/B52_flight2.wmv

It's been done. Vision Recumbents put a 15 pound thrust engine on the
back of one of their bikes, and it pushed the bike to 30 mph. Loud
mother, too. Pictures and movies of it in action here:
http://www.outsideconnection.com/gallant/hpv/vision/

Jeff

Any idea on what happenned to the Jet Sabre in the ATP-Vision auction?



Tim Arfons (son of Art Arfons) used this 90 hp JFS 100 13A turbine in powering a bar stool over 40 mph powered http://www.turbinegroup.com/page2.html to get into the Guiness book for the fastest barstool. This company makes the race track dryers you see at major oval/drag racing events.


Here is the jet powered Penny Farthing page:
http://www.pennyfarthing.dabsol.co.uk/pulse-je.htm

.

 

[Dave Larrington]

Bruce W.1 wrote:
> I was thinking of putting a small turbine engine on my road bicycle,
> just for grins. How many pounds of thrust do you think would be
> needed to maintain 20 mph?
>
> There's a bunch of tiny jet engines for RC airplanes with from 10 to
> 50 lbs of thrust. Here's one:
> http://www.franktiano.com/t-750.htm
>
> Here's a video of the mother of all RC airplanes:
> http://www.mcgirt.net/RC/VIDEOS/Giant_B52/B52_flight2.wmv

A Several of years ago one Paul Ford fitted a jet engine to a Windcheetah
recumbent trike. 50 mph and 180 dB... Pic at:

URL:http://www.micro-jet.freeserve.co.uk/jetbike.htm

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
Whatever it is, I'd like it in mango & passion fruit, please.

 

[Mike Jacoubowsky]

> Dear Mike,
>
> Typically jet engines are listed at around 140 dB. It takes
> a rocket launch to reach 180 dB.
>
> http://www.800nonoise.com/tutorial_noiselist.htm
>
> Carl Fogel

Carl: There is reason to believe that list is seriously flawed. For example,
it says that you can safely listen to a screaming child (90db) for 8 hours.
Find me one such person.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

 

[Dave Larrington]

Mike Jacoubowsky wrote:
>> A Several of years ago one Paul Ford fitted a jet engine to a
>> Windcheetah recumbent trike. 50 mph and 180 dB... Pic at:
>
> 180 db???!!! I don't think it was the exhaust that was propelling it
> forward, it was the sound!
>
> Are you sure about that noise figure? That seems high enough to almost
> vaporize anything nearby.

I merely quote, Sirrah!

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
If you want a bicycle, buy a bicycle. If you want something that
folds, buy a deckchair.

 

[Zog The Undeniable]

Bruce W.1 wrote:

> I was thinking of putting a small turbine engine on my road bicycle,
> just for grins. How many pounds of thrust do you think would be needed
> to maintain 20 mph?

If you assume the power requirement is 180W, then about 4.5lbs.