How To? Crank Without Crank Arm

Discussion in 'Recumbent bicycles' started by Tony, Jan 22, 2003.

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  1. Tony

    Tony Guest

    Hi Gang,

    I'm building up an Econbent frameset. The Econbent plans call for making an intermediate drive from
    a freewheel, mounting the drive to a bottom bracket shell which is already in place on the frame.

    However, I thought using a second bottom bracket (similar to the BikeE RX or Cannondale intermediate
    drives) would provide a neater chainline, easier shifting, and smoother operation.

    How do I mount chainrings on the second bottom bracket without a crankarm?

    You can tell I'm a mechanical tyro, right? :)

    Thanks,

    Tony
     
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  2. Tony

    Tony Guest

    Hi Gang,

    I'm building up an Econbent frameset. The Econbent plans call for making an intermediate drive from
    a freewheel, mounting the drive to a bottom bracket shell which is already in place on the frame.

    However, I thought using a second bottom bracket (similar to the BikeE RX or Cannondale intermediate
    drives) would provide a neater chainline, easier shifting, and smoother operation.

    How do I mount chainrings on the second bottom bracket without a crankarm?

    You can tell I'm a mechanical tyro, right? :)

    Thanks,

    Tony
     
  3. Tony asked:

    > How do I mount chainrings on the second bottom bracket without a crankarm?

    Chainset, hacksaw, elbow grease?

    Dave Larrington - http://legslarry.crosswinds.net/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  4. Tom Sherman

    Tom Sherman Guest

    Tony wrote:
    >
    > Hi Gang,
    >
    > I'm building up an Econbent frameset. The Econbent plans call for making an intermediate drive
    > from a freewheel, mounting the drive to a bottom bracket shell which is already in place on
    > the frame.
    >
    > However, I thought using a second bottom bracket (similar to the BikeE RX or Cannondale
    > intermediate drives) would provide a neater chainline, easier shifting, and smoother operation.
    >
    > How do I mount chainrings on the second bottom bracket without a crankarm?
    >
    > You can tell I'm a mechanical tyro, right? :)

    Hi Tony,

    Another option would be to use a simple idler and an internally geared rear hub such as the SRAM
    Dual Drive 3x8 or 3x9. These are fairly expensive at ~$170 (used Sachs/SRAM 3x7 hubs should be well
    under $100), but you should be able to afford it unless you have already spent all my money. ;)

    Tom Sherman - Quad Cities USA (Illinois side) RANS "Wavewind" and Rocket, Earth Cycles Sunset and
    Dragonflyer
     
  5. Tony asked:

    > How do I mount chainrings on the second bottom bracket without a crankarm?

    Chainset, hacksaw, elbow grease?

    Dave Larrington - http://legslarry.crosswinds.net/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  6. Tom Sherman

    Tom Sherman Guest

    Tony wrote:
    >
    > Hi Gang,
    >
    > I'm building up an Econbent frameset. The Econbent plans call for making an intermediate drive
    > from a freewheel, mounting the drive to a bottom bracket shell which is already in place on
    > the frame.
    >
    > However, I thought using a second bottom bracket (similar to the BikeE RX or Cannondale
    > intermediate drives) would provide a neater chainline, easier shifting, and smoother operation.
    >
    > How do I mount chainrings on the second bottom bracket without a crankarm?
    >
    > You can tell I'm a mechanical tyro, right? :)

    Hi Tony,

    Another option would be to use a simple idler and an internally geared rear hub such as the SRAM
    Dual Drive 3x8 or 3x9. These are fairly expensive at ~$170 (used Sachs/SRAM 3x7 hubs should be well
    under $100), but you should be able to afford it unless you have already spent all my money. ;)

    Tom Sherman - Quad Cities USA (Illinois side) RANS "Wavewind" and Rocket, Earth Cycles Sunset and
    Dragonflyer
     
  7. "Dave Larrington" skrev... *snip*

    A man with a black Elan tailbox on his Baron.

    Managed to catch your webpage at a time where it wasn't down. Do you have the carbon version and if
    so ... is it painted/gelcoated black or can you see the carbon? (hard to tell from the pics)

    Mikael
     
  8. "Dave Larrington" skrev... *snip*

    A man with a black Elan tailbox on his Baron.

    Managed to catch your webpage at a time where it wasn't down. Do you have the carbon version and if
    so ... is it painted/gelcoated black or can you see the carbon? (hard to tell from the pics)

    Mikael
     
  9. John Foltz

    John Foltz Guest

    Tony wrote:

    >> BTW how did they suggest you mate the freewheel to the bb shell?
    >
    > If I understand correctly, the freewheel is modified by removing the pawls (just like rorschandt
    > mentioned earlier in the thread) and cross threading the BB shell.
    >
    Nothing needs to be cross-threaded. You use the right hand cup from an old-style bottom bracket.
    Screw it into the freewheel, then screw the other end into the bb shell on the bike. This setup
    might look better, but the chainring idea will probably work better.
    --

    John Foltz --- O _ Baron --- _O _ V-Rex 24/63 --- _\\/\-%)
    _________(_)`=()___________________(_)= (_)_____
     
  10. Jeff Wills

    Jeff Wills Guest

    [email protected] (Tony) wrote in message news:<[email protected]>...
    > On Fri, 10 Jan 2003 17:17:47 -0000, "Dave Larrington" <[email protected]> wrote:

    > >Chainset, hacksaw, elbow grease?
    >
    > Why didn't I think of that? :)
    >
    > Actually, I was hoping to find a manufactured, armless crank spider. Does such a beast exist?
    >

    Bikee and Cannondale have both used this animal ("armless spider", indeed!). There's a picture at
    http://www.cannondale.com/bikes/02/cusa/model-2BM.html

    However, I would be willing to bet that getting one from Cannondale or from whoever has the cache of
    Bikee spares would be as difficult as making your own from a bunged-up right side crank from a shop.
    Heck, I've got one sitting in my "spares" bin right now- but it might go onto a project tomorrow, so
    you can't have it. So there. ;-)

    Jeff
     
  11. John Foltz

    John Foltz Guest

    Tony wrote:

    >> BTW how did they suggest you mate the freewheel to the bb shell?
    >
    > If I understand correctly, the freewheel is modified by removing the pawls (just like rorschandt
    > mentioned earlier in the thread) and cross threading the BB shell.
    >
    Nothing needs to be cross-threaded. You use the right hand cup from an old-style bottom bracket.
    Screw it into the freewheel, then screw the other end into the bb shell on the bike. This setup
    might look better, but the chainring idea will probably work better.
    --

    John Foltz --- O _ Baron --- _O _ V-Rex 24/63 --- _\\/\-%)
    _________(_)`=()___________________(_)= (_)_____
     
  12. Jeff Wills

    Jeff Wills Guest

    [email protected] (Tony) wrote in message news:<[email protected]>...
    > On Fri, 10 Jan 2003 17:17:47 -0000, "Dave Larrington" <[email protected]> wrote:

    > >Chainset, hacksaw, elbow grease?
    >
    > Why didn't I think of that? :)
    >
    > Actually, I was hoping to find a manufactured, armless crank spider. Does such a beast exist?
    >

    Bikee and Cannondale have both used this animal ("armless spider", indeed!). There's a picture at
    http://www.cannondale.com/bikes/02/cusa/model-2BM.html

    However, I would be willing to bet that getting one from Cannondale or from whoever has the cache of
    Bikee spares would be as difficult as making your own from a bunged-up right side crank from a shop.
    Heck, I've got one sitting in my "spares" bin right now- but it might go onto a project tomorrow, so
    you can't have it. So there. ;-)

    Jeff
     
  13. Tony

    Tony Guest

    On Fri, 10 Jan 2003 17:48:17 -0500, John Foltz <[email protected]> wrote:

    > >
    >Nothing needs to be cross-threaded. You use the right hand cup from an old-style bottom bracket.
    >Screw it into the freewheel, then screw the other end into the bb shell on the bike. This setup
    >might look better, but the chainring idea will probably work better.

    Thanks for clearing that up for me, John. Now I see how both methods would work, and I'm still
    leaning to using a chainset.

    Regards,

    Tony
     
  14. Tony

    Tony Guest

    On Fri, 10 Jan 2003 17:48:17 -0500, John Foltz <[email protected]> wrote:

    > >
    >Nothing needs to be cross-threaded. You use the right hand cup from an old-style bottom bracket.
    >Screw it into the freewheel, then screw the other end into the bb shell on the bike. This setup
    >might look better, but the chainring idea will probably work better.

    Thanks for clearing that up for me, John. Now I see how both methods would work, and I'm still
    leaning to using a chainset.

    Regards,

    Tony
     
  15. Rorschandt

    Rorschandt Guest

    [email protected] (Jeff Wills) wrote in news:[email protected]:

    > [email protected] (Tony) wrote in message news:<[email protected]>...
    >> On Fri, 10 Jan 2003 17:17:47 -0000, "Dave Larrington" <[email protected]> wrote:
    >
    >> >Chainset, hacksaw, elbow grease?
    >>
    >> Why didn't I think of that? :)
    >>
    >> Actually, I was hoping to find a manufactured, armless crank spider. Does such a beast exist?
    >>
    >
    > Bikee and Cannondale have both used this animal ("armless spider", indeed!). There's a picture at
    > http://www.cannondale.com/bikes/02/cusa/model-2BM.html
    >
    > However, I would be willing to bet that getting one from Cannondale or from whoever has the cache
    > of Bikee spares would be as difficult as making your own from a bunged-up right side crank from a
    > shop. Heck, I've got one sitting in my "spares" bin right now- but it might go onto a project
    > tomorrow, so you can't have it. So there. ;-)
    >
    > Jeff
    >

    There's a good idea. Ask around at the LBS for a crank that has the pedal hole stripped out. 'twould
    be a shame to saw up a good crank. easier than my current mid-drive solution, which involved brazing
    a spider onto the back of a cassette body, and machining some aluminum stuff for bearings, and ...
    rorschandt
     
  16. Rorschandt

    Rorschandt Guest

    [email protected] (Jeff Wills) wrote in news:[email protected]:

    > [email protected] (Tony) wrote in message news:<[email protected]>...
    >> On Fri, 10 Jan 2003 17:17:47 -0000, "Dave Larrington" <[email protected]> wrote:
    >
    >> >Chainset, hacksaw, elbow grease?
    >>
    >> Why didn't I think of that? :)
    >>
    >> Actually, I was hoping to find a manufactured, armless crank spider. Does such a beast exist?
    >>
    >
    > Bikee and Cannondale have both used this animal ("armless spider", indeed!). There's a picture at
    > http://www.cannondale.com/bikes/02/cusa/model-2BM.html
    >
    > However, I would be willing to bet that getting one from Cannondale or from whoever has the cache
    > of Bikee spares would be as difficult as making your own from a bunged-up right side crank from a
    > shop. Heck, I've got one sitting in my "spares" bin right now- but it might go onto a project
    > tomorrow, so you can't have it. So there. ;-)
    >
    > Jeff
    >

    There's a good idea. Ask around at the LBS for a crank that has the pedal hole stripped out. 'twould
    be a shame to saw up a good crank. easier than my current mid-drive solution, which involved brazing
    a spider onto the back of a cassette body, and machining some aluminum stuff for bearings, and ...
    rorschandt
     
  17. Mikael asked:

    > Do you have the carbon version and if so ... is it painted/gelcoated black or can you see the
    > carbon? (hard to tell from the pics)

    It *is* the carbon version, and it's unpainted, so you *can* see the carbon weave if you
    look closely.

    Dave Larrington - http://legslarry.crosswinds.net/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  18. Mikael asked:

    > Do you have the carbon version and if so ... is it painted/gelcoated black or can you see the
    > carbon? (hard to tell from the pics)

    It *is* the carbon version, and it's unpainted, so you *can* see the carbon weave if you
    look closely.

    Dave Larrington - http://legslarry.crosswinds.net/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  19. "Dave Larrington" skrev...
    > It *is* the carbon version, and it's unpainted, so you *can* see the carbon weave if you look
    > closely.

    Thank ye. I ascribe to the "If you got it ... flaunt it"-school of thought.

    Mikael
     
  20. "Dave Larrington" skrev...
    > It *is* the carbon version, and it's unpainted, so you *can* see the carbon weave if you look
    > closely.

    Thank ye. I ascribe to the "If you got it ... flaunt it"-school of thought.

    Mikael
     
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