Advertise on Bikeforums.net



User Tag List

Results 1 to 15 of 15
  1. #1
    Senior Member rabbitt's Avatar
    Join Date
    Mar 2005
    Location
    El Paso, TX
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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!

  2. #2
    cyclopath vik's Avatar
    Join Date
    Apr 2006
    Location
    Victoria, BC
    My Bikes
    Surly Krampus, Surly Straggler, Pivot Mach 6, Bike Friday Tikit, Bike Friday Tandem, Santa Cruz Nomad
    Posts
    5,237
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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

  3. #3
    Recumbent Evangelist
    Join Date
    Mar 2005
    Location
    Kitchener, Ontario
    My Bikes
    Rebel Cycles Trike, Trek 7500FX
    Posts
    2,991
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I'm sure it would run like clockwork.
    www.rebel-cycles.com

    The official Canadian dealer of TW-Bents recumbent bicycles!

  4. #4
    Senior Member BlazingPedals's Avatar
    Join Date
    Dec 2004
    Location
    Middle of da Mitten
    My Bikes
    Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, homebuilt recumbent
    Posts
    7,160
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(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?

  5. #5
    Recumbent Evangelist
    Join Date
    Mar 2005
    Location
    Kitchener, Ontario
    My Bikes
    Rebel Cycles Trike, Trek 7500FX
    Posts
    2,991
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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!
    www.rebel-cycles.com

    The official Canadian dealer of TW-Bents recumbent bicycles!

  6. #6
    Senior Member Shaman's Avatar
    Join Date
    May 2006
    Posts
    386
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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
    Today is a great day to ride!

  7. #7
    Senior Member
    Join Date
    Dec 2004
    My Bikes
    Electra Townie 7D
    Posts
    3,398
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    use a natural spring

  8. #8
    Senior Member rabbitt's Avatar
    Join Date
    Mar 2005
    Location
    El Paso, TX
    Posts
    60
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    reply

    what do you mean by that?

  9. #9
    Senior Member
    Join Date
    Apr 2006
    Posts
    341
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Springs can be made of many things. I believe the rear leaf spring on the new Corvette's is made of carbon fiber.
    Pax
    Tulsa, OK
    '12 Gravity Zilla, '12 Giant Talon 29'r, '88 Jamis Quest, Redline 9.2.5 (wrecked), Steyr Clubman, Raleigh Technium, GT Hardtail, DK Signal, Eastern Shovelhead

  10. #10
    Junior Member
    Join Date
    Sep 2006
    Posts
    19
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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

  11. #11
    Recumbent Evangelist
    Join Date
    Mar 2005
    Location
    Kitchener, Ontario
    My Bikes
    Rebel Cycles Trike, Trek 7500FX
    Posts
    2,991
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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."
    www.rebel-cycles.com

    The official Canadian dealer of TW-Bents recumbent bicycles!

  12. #12
    No Rocket Surgeon eubi's Avatar
    Join Date
    Jan 2005
    Location
    Corona and S. El Monte, CA
    My Bikes
    Cannondale D600, Dahon Speed T7
    Posts
    1,648
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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!

  13. #13
    Senior Member
    Join Date
    Jul 2005
    Posts
    3,192
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Whew! No more weed for rabbitt. bk
    Last edited by bkaapcke; 12-07-06 at 05:11 PM.

  14. #14
    Senior Member GeezerGeek's Avatar
    Join Date
    Sep 2004
    Location
    Minnesota
    My Bikes
    1993 Infinity LWB, Bacchetta
    Posts
    221
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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.

  15. #15
    Dr.Deltron
    Guest
    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)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •