Designing Hand Bike

Discussion in 'Research and Questionnaires' started by finleycorker, 8 Jan 2018.

?
  1. yes

    2 vote(s)
    40.0%
  2. no

    0 vote(s)
    0.0%
  3. varies

    3 vote(s)
    60.0%
  1. finleycorker

    finleycorker Member

    Hi all, Im studying product design for my a level project and need some feedback for my product. My product is a hand bike attachment that the user can clip in and go. When researching mobility equipment i have found that most mobility equipment is highly expensive and out of most people price range.


    Are users finding mobility products are unaffordable?

    is there a gap in the market for a product that focuses on function and price, rather than the high tech

    How much would you be willing to pay for a hand bike attachment.
     
  2. MichaelW2

    MichaelW2 Über Member

    Products for the mobility and independent living market usually have lots of careful and expensive design, complex manufacturing, small productions runs not worthy of cheap far-eastern outsourcing and are made by small companies with few other products to balance the business. Very few people get rich this way.
     
    raleighnut likes this.
  3. raleighnut

    raleighnut Guru

    Location:
    On 3 Wheels
    A good point, when I built my Electric trike it cost me just under a grand for all new parts (except for the saddle which I 'borrowed' from another bike. The cheapest 'ready made' electric trike I could see on the Internet was @ £1,600 and uses the same motor.

    trike 001.JPG
     
    roadrash likes this.
  4. Sharky

    Sharky Veteran

    Location:
    Kent
    I can't visualise how this would work? Is it for a solo bike, tandem or trike etc?

    No experience of hand operated bikes, but my daughter being autistic was unable to ride a normal bike and needed help to get on/off and the solution we found was a tandem trike, which was obviously stable when stationery. I presume anyone using a hand attachment may have difficulty mounting/dismounting, so this is an issue that needs to be resolved as well.

    Or have I miss-read your post and the hand attachment is for a different purpose?

    Good luck with your A Levels
     
  5. ADarkDraconis

    ADarkDraconis Cardinal Member

    Location:
    Ohio, USA
    I also was wondering what the attachment is for, the post isn't quite clear. My cousin has cerebral palsy and is wheelchair-bound, and when he was younger he had a hand-pedal bike. He did need help to get from his chair to his bike, his mom helped him. He hasn't had one in years because they are difficult to manage by yourself and once he outgrew his small one it was too expensive to buy an adult-sized one.
     
    Sharky likes this.
  6. Sharky

    Sharky Veteran

    Location:
    Kent
    I guess we will never know, the OP was posted on 8th Jan and hasn't been since.
     
  7. ADarkDraconis

    ADarkDraconis Cardinal Member

    Location:
    Ohio, USA
    How unfortunate :sad:
     
    Sharky likes this.
  8. Perhaps if @finleycorker emerges from the shadows @mickle could assist with you with his vast experience on the subject :okay:
     
    mickle, ADarkDraconis and Sharky like this.
  9. Innit
     
    Drago and smokeysmoo like this.
  10. OP
    OP
    finleycorker

    finleycorker Member

    Hi sorry for the long reply. This is currently my design for the front of my project. Screen Shot 2018-03-13 at 14.59.27.png
     
  11. OP
    OP
    finleycorker

    finleycorker Member

    Screen Shot 2018-03-13 at 15.23.41.png this shows an exploded drawing
     
  12. OP
    OP
    finleycorker

    finleycorker Member

    I have also added a toggle push clamp that is permanently attached to the wheel chair which allows users to attach the hand bike by them selves pushing on the clamp which will raise the front caster wheels by 3cm. This will allow the user the attach the hand bike by pushing the frame in to the other clamp that is attached to the wheel chair and clip in. Once there clipped in they can pull up the lifter so its resting on the caster wheels and then the user can ride away. All the clamps used to attach the bike are toggle clamps so the user doesn't need hand strength. This picture is a visual of how its attached. Screen Shot 2018-03-13 at 15.34.42.png to tighten it safely
     
  13. Hallo again Finley.

    Do you have a big flat white wall you can draw on - or stick a large piece of paper to?

    Here's some parameters: 'Reach' is measured from the front surface of the seat back to the furthest forward position of the handle.

    The bigger the front wheel the better traction and lower rolling resistance you'll have - but you have to trade wheel size against the eternal problem with hand crank propelled wheelchairs - lack of traction. What you're building is a front wheel drive tricycle which has almost all of the rider's weight over the rear wheels. So you want the front wheel to be as close to rider as possible without clashing with the feet. Most clip-ons therefore use a twenty inch (406) wheel - for which an enormous range of tyres is available. Including off road tyres.

    Clip-on hand-cycle units cannot fit on a regular scissor action folding wheelchair. They will only fit on a rigid chair. And rigid chairs are invariably expensive - if not custom built. This rather goes against your stated aim of making it inexpensive...

    Plotting your machine in profile onto a wall is the best way of getting a quick understanding on the shape of it. Looking at your sketches you'll need to move the front wheel forward and the 'bottom bracket' rearwards. The relationship of the steering axis and the tyre's contact point on the road is CRUCIAL to the safe operation of your trike. Research: 'head angle', 'trail', 'castor effect', 'fork offset'.

    Brakes. Coaster brakes are almost universal on hand cycles. You'll definitely need a second brake, either rim or disc. It'll need gears, and the only way to get gears with a coaster brake is with an internal geared hub such as are made by Shi**no and Sturmey Archer. You will definitely need to consider where you mount the gear and brake controls. Mount them on the handles and they'll start deteriorating with the first turn of the handles. Mount them on the frame somewhere and your rider will need to take her hands of the handles to use them. Hand cycles devour cables.

    Purpose built upright hand trikes have a longer wheelbase to compensate for the lack of weight over the front wheel. But if you move the wheels rearward on a wheelchair you might make it a better hand tricycle but destroy it's ability to function as a chair. Some chairs have a plate on each side with two sets of wheel locating holes in. Locate the wheel forwards to use it as a chair & pop them in the back holes for use as a trike. Easy to do with standard QR wheels - but adds cost...

    Very few people use handles which are flat/horizontal. Most use handles which are close to vertical - about 10 degrees or so camber.

    If you need to know any more than this I'm going to have to charge you.
     
  14. Sharky

    Sharky Veteran

    Location:
    Kent
    A couple of thoughts -
    What is the reach? If the user is sitting back then the hand crank cant be more than an arm's length away at the furthest point and must allow for steering.

    And what is the braking system

    Good luck with your project.
     
    ADarkDraconis likes this.
  15. OP
    OP
    finleycorker

    finleycorker Member

    Thank you guys I really appreciate your feed back. Its really helpful. Im not 100% sure what the reach is at the moment. I will have to study anthropometric data data and will design for the 90th percentile.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice