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  • Geared Hub

    I am designing a prone-suspension bicycle that requires crankarms attached to the axle of a geared hub...something like the attached images of Frank Bonsch's creations (posted 25-SEP-2007).

    Can anyone point to the current state-of-the-art, or a perhaps a gifted machinist who might want to have a go at prototyping such a beast?

    Cheers,
    Tom Piszkin
    Airo-Series, Inc.
    www.TitanFlexBikes.com
    Attached Files

  • #2
    You are going to want to look for Schlumpf hubs. They have a 1.5:1 ratio and are shiftable on the fly. They are available with either a square tapered spindle or ISIS.

    If it doesn't have to be brand new there are usually one or two for sale in the trading post. If you want new I am not sure if anyone keeps any stock in the US but there is at least one ISIS version at the canadian UDC store http://www.municycle.ca/kris-holm-sc...hub-p-904.html
    or you can order direct from Schlumpf http://www.schlumpf.ch/hp/uni/uni_engl.htm
    My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we’ll change the world. - Jack Layton

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    • #3
      I fell asleep thinking "what on earth could a high end road bike company want with a geared unicycle hub" and I woke up thinking: HIGHER GEAR! FREEWHEEL!

      So here is something else you might find interesting:
      http://www.unicyclist.com/forums/sho...d.php?t=112267


      *back to bed*
      My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we’ll change the world. - Jack Layton

      Comment


      • #4
        Hey Eric, Thanks for the reply. I've looked at the Schulmpf--not ideal.
        We are willing to finance an R&D effort to produce what looks like UniFrank (Frank Bonsch) rendered several years ago.

        Does anyone know how to contact him directly?

        Cheers,
        Tom

        Comment


        • #5
          Do you need a freewheel ?
          http://monocycle.info
          http://www.leblogdumonocycle.fr/
          CITY XTP 26", MUNI KH26" & KH29", ROAD Oracle 32" and KH36"
          my goal : a 3 geared 29" to have only one uni for all kind of rides :-)

          Comment


          • #6
            Originally posted by TITANFLEX View Post
            Hey Eric, Thanks for the reply. I've looked at the Schulmpf--not ideal.
            We are willing to finance an R&D effort to produce what looks like UniFrank (Frank Bonsch) rendered several years ago.

            Does anyone know how to contact him directly?

            Cheers,
            Tom
            It looks like it's been a couple years since Frank was active on the forums but have you tried to send him a Private Message through this forum yet? It's possible it's still hooked into a current email address. It looks like Frank's web site was hosted on a provider that no longer serves it. I did find some interesting CAD movies:

            http://www.angelfire.com/film/unicycle/

            In the movie titled "Ansicht1_min.avi" it shows an arm coming off the hub. I'm not sure what the purpose of this is. That design also has sealed bearings on the axle. The 3.8x Sturmey-Archer hub that JR Drift Trikes commissioned (and I've pre-ordered) has the fork connecting to it similar to that little arm.

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            • #7
              Hey Waaalrus, thanks for the link to these animated illustrations. UniFrank did some pioneering work here. We're looking to advance this art beyond Schlumpf's 2-speed hub and apply it to the larger bi-cycle market.

              Cheers,
              Tom

              Comment


              • #8
                Originally posted by TITANFLEX View Post
                Hey Waaalrus, thanks for the link to these animated illustrations. UniFrank did some pioneering work here. We're looking to advance this art beyond Schlumpf's 2-speed hub and apply it to the larger bi-cycle market.

                Cheers,
                Tom
                Cool. This sounds pretty much like the inverse of what I proposed in this thread (You: take a unicycle wheel design and lay it down to make a bike, Me: take a bike design and stand it up to make a unicycle). Let me know if you need someone to stress test it by riding the wheel like a unicycle (with full body weight on it) or to demonstrate a wheelie. I would definitely be in the market for such a hub as long as it freewheels.

                Comment


                • #9
                  It would probably be worth it to contact Greg Harper as well. He is harper on the forums. He is usually full of good ideas.
                  My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we’ll change the world. - Jack Layton

                  Comment


                  • #10
                    you can also contact "bouin-bouin" on this forum: he has a design for a 2 speeds hub.
                    One Wheel : bear necessity
                    (Abuello RodoMancat)

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