Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Recumbent What IS that thing?! Recumbents may be odd looking, but they have many advantages over a "wedgie" bicycle. Discuss the in's and out's recumbent lifestyle in the recumbent forum.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 10-30-06, 11:27 AM   #1
rabbitt
Senior Member
Thread Starter
 
rabbitt's Avatar
 
Join Date: Mar 2005
Location: El Paso, TX
Bikes:
Posts: 60
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
torsion spring hyper-drive

Lately i've been imagining wild new vehicles, none of which could probably work. But I did learn about torsion springs and immediately i thought "wouldn't it be cool to have a torsion spring on a bike that you can charge by pedaling, then release it for hyper speed?! (hyper speed meaning 30 on a DF and possibly 30-40 on a bent). Has anyone else thought of this? I'm sure there are problems, so all you technically inclined people, now's your chance to burst my bubble. Let me know what you think!
rabbitt is offline   Reply With Quote
Old 10-30-06, 11:40 AM   #2
vik 
cyclopath
 
vik's Avatar
 
Join Date: Apr 2006
Location: Victoria, BC
Bikes: Surly Krampus, Surly Straggler, Pivot Mach 6, Bike Friday Tikit, Bike Friday Tandem, Santa Cruz Nomad
Posts: 5,265
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How about instead of pedalling to charge it you use downhill braking or I guess any braking force to charge the the spring? That could give you a nice little kick when you needed it.

The problem with this idea - like so many other cycling "improvements" is figuring out if the benefits out weigh the cost, weight and added complexity.
__________________
safe riding - Vik
VikApproved
vik is offline   Reply With Quote
Old 10-30-06, 11:49 AM   #3
jeff-o
Recumbent Evangelist
 
Join Date: Mar 2005
Location: Kitchener, Ontario
Bikes: Rebel Cycles Trike, Trek 7500FX
Posts: 2,991
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm sure it would run like clockwork.
jeff-o is offline   Reply With Quote
Old 10-30-06, 12:25 PM   #4
BlazingPedals
Senior Member
 
BlazingPedals's Avatar
 
Join Date: Dec 2004
Location: Middle of da Mitten
Bikes: Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, homebuilt recumbent
Posts: 8,945
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 103 Post(s)
Quote:
Originally Posted by jeff-o
I'm sure it would run like clockwork.
lol - would that be the second hand or the hour hand?
BlazingPedals is offline   Reply With Quote
Old 10-30-06, 12:51 PM   #5
jeff-o
Recumbent Evangelist
 
Join Date: Mar 2005
Location: Kitchener, Ontario
Bikes: Rebel Cycles Trike, Trek 7500FX
Posts: 2,991
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by BlazingPedals
lol - would that be the second hand or the hour hand?
It all depends on what gear ratio you're using!
jeff-o is offline   Reply With Quote
Old 10-30-06, 03:05 PM   #6
Shaman
Senior Member
 
Shaman's Avatar
 
Join Date: May 2006
Bikes:
Posts: 386
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Since springs are made of steel, the weight would be counter productive. In many ways it makes sense to harness lost energy such as braking energy for controlled release. I would put it in the catagory of constant power cycling where you wind the spring with peddling but the price would be lag time from pedal to motion. You'd definitely need a one way lock device or you'll be holding the spring back with your legs at every red light and stop sign. It would also harness that wasted high torque start energy and use it more effectively. I doubt that you''ll be capturing enough energy to make it up a steep incline. Along with this concept lies its other partner, the gyro, but that's another story
Shaman is offline   Reply With Quote
Old 10-31-06, 05:58 PM   #7
scottogo
Senior Member
 
Join Date: Dec 2004
Bikes: Electra Townie 7D
Posts: 3,398
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
use a natural spring
scottogo is offline   Reply With Quote
Old 11-02-06, 03:43 PM   #8
rabbitt
Senior Member
Thread Starter
 
rabbitt's Avatar
 
Join Date: Mar 2005
Location: El Paso, TX
Bikes:
Posts: 60
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
reply

what do you mean by that?
rabbitt is offline   Reply With Quote
Old 11-06-06, 06:24 PM   #9
WorldPax
Senior Member
 
Join Date: Apr 2006
Bikes:
Posts: 341
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Springs can be made of many things. I believe the rear leaf spring on the new Corvette's is made of carbon fiber.
WorldPax is offline   Reply With Quote
Old 11-07-06, 03:52 PM   #10
airxxxwolf
Junior Member
 
Join Date: Sep 2006
Bikes:
Posts: 19
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Been There....

Quote:
Originally Posted by rabbitt
"wouldn't it be cool to have a torsion spring on a bike that you can charge by pedaling, then release it for hyper speed?! (hyper speed meaning 30 on a DF and possibly 30-40 on a bent)
I already do those speeds on my lowracer....without a spring.......

Don
airxxxwolf is offline   Reply With Quote
Old 11-07-06, 05:20 PM   #11
jeff-o
Recumbent Evangelist
 
Join Date: Mar 2005
Location: Kitchener, Ontario
Bikes: Rebel Cycles Trike, Trek 7500FX
Posts: 2,991
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by airxxxwolf
I already do those speeds on my lowracer....without a spring.......

Don
Same on my trike, though I call it "gravity assist."
jeff-o is offline   Reply With Quote
Old 12-06-06, 01:41 PM   #12
eubi
No Rocket Surgeon
 
eubi's Avatar
 
Join Date: Jan 2005
Location: Corona and S. El Monte, CA
Bikes: Cannondale D600, Dahon Speed T7
Posts: 1,648
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm guessing you are talking about a torsion bar type spring?

They work OK for auto suspensions, but they have a limited travel.
__________________
Fewer Cars, more handlebars!
eubi is offline   Reply With Quote
Old 12-07-06, 11:15 AM   #13
bkaapcke
Senior Member
 
Join Date: Jul 2005
Bikes:
Posts: 3,227
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Whew! No more weed for rabbitt. bk

Last edited by bkaapcke; 12-07-06 at 06:11 PM.
bkaapcke is offline   Reply With Quote
Old 12-23-06, 09:26 AM   #14
GeezerGeek
Senior Member
 
GeezerGeek's Avatar
 
Join Date: Sep 2004
Location: Minnesota
Bikes: 1993 Infinity LWB, Bacchetta
Posts: 224
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What is important is the amount of energy stored versus the weight versus the efficiency of converting the energy twice. The cost and safety of the mechanisms can prohibit mass production. Springs store energy by strain. They have a very high weight to energy ratio so they are not practical. If you want to store strain energy in a torsion spring, rubber bands have a far better energy to weight ratio than steel but watch out when they break.

A flywheel that is hooped shaped running extremely fast in a vacuum can store a lot of energy for its weight. If designed right, this has one of the highest energy density to weight ratios of mechanical gizmos.

Bikes have tubes. These are built in pressure vessels that can store compressed air if they are sealed. This is virtually a free storage system that would add little to the weight of the bike. The problem is that compressors and expanders are not very efficient.

I think that people are working on hybrid electric bikes that store energy as chemical energy in batteries. In a few years you will pobably see hybrid bikes using ultracapacitors instead of batteries.

Of course, the highest stored energy to weight is nuclear energy.
GeezerGeek is offline   Reply With Quote
Old 12-23-06, 12:21 PM   #15
Dr.Deltron
Guest
 
Bikes:
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
Quote:
Originally Posted by Shaman
Along with this concept lies its other partner, the gyro, but that's another story
That's great! I guess I'll have to dig through my computer for the pics of a Rasta guy who came to town about 6-7 months ago. He was riding a 650 lb mobile home bicycle! It used to be around 800 lbs when he had the bathroom attached. I'm not kidding about this. The vehicle had only 2 wheels but the driveline consisted of something like 7 deraileurs and a flywheel. The rear wheel was a car wheel and the front was from a moped. He could make this thing go like 20 mph over almost any terrain. He wanted to modify my Greenspeed tandem to have this set-up. (no way, Jose!)
But I must admit, his rig did cause me to think more about such an application.
I'll post some pics (probably sometime AFTER Christmas)
  Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 12:17 PM.