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Shorter cranks on Double Vision

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Recumbent bicycles
Published
27 October 2003
Last activity
31 October 2003
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Perry
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  1. I did a Google search to see if any new pertinent information had come to light lately. All that
    popped up were posts of mine, expounding the gloriousness of shorter cranks. I am at least a year
    into using shorter cranks (165's) and I positively have no knee pain on my single bike. The tandem
    (Double Vision) has 175's and my knee always hurts when we ride
    it.Any new ideas on shortening cranks on the DV? I called Vision and Ricky Comar said it would cost
    about $15,000. Machining, R& D, prototypes, etc. (I have heard that Ricky Comar is not at Vision
    anymore...) Perry bentcajungirl down to just a Double Vision New R-40 Husband's R-44 and still
    the El Camino.

  2. Hello: if you donot have IPS or splined crank i know of a machine shop that will drill and tap them
    out for you. if intrested please e-mail me back. Thank you Earl GRR,RANS V2 Ti Rush,Ti Pursuit

  3. Hi Earl, I do have IPS. (and I believe they're tapered) Why does that make a difference? Perry

    "Guess Who I Am" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Hello: if you donot have IPS or splined crank i know of a machine shop that will


    drill

    Quoted message said:

    and tap them out for you. if intrested please e-mail me back. Thank you Earl GRR,RANS V2 Ti
    Rush,Ti Pursuit

  4. Perry, I do not know if the DV is something unique or just uses regular tandem components.
    Maybe what I am posting is useless to you. But hopefully it is not. St. John Street Cycles.
    sjscycles.comvIndex.htm has beautiful Thorn cranks for front and rear
    tandems 140-175mm

    In the index do NOT look under cranksets. Look under "Chainsets" then "Tandem chainsets/cranks". I
    have a triple solo from them in 150mm and it is very nicely done. I picked the TA rings. Their
    polish matches the crank and they are ramped and pinned. Note which are marked outer, middle, and
    inner. Please note on pricing, US customers do not have to pay the value added tax so the listed
    price must be reduced by that amount. Also, when I ordered the arms, rings, and bolts I was promptly
    informed that what I ordered was considered a kit so they assembled it for me and greatly reduced
    the price. Delivered to my door in Sacramento from Jolly Olde in 9 days from my order. Nice chaps to
    deal with. Spot on and all that rot. Good luck. Don

  5. "Perry" <[email hidden]> wrote in message
    news:<[email hidden]>... <snip>

    Quoted message said:

    Any new ideas on shortening cranks on the DV? I called Vision and Ricky Comar said it would cost
    about $15,000. Machining, R& D, prototypes, etc. (I have heard that Ricky Comar is not at Vision
    anymore...)

    Yeah, Ricky left a couple months back.

    Regarding the cranksets: the IPS system required some special machining to accomodate the freewheel
    mechanism. A really good machinist might be able to set up shorter cranks for IPS- but it's fairly
    sensitive. You might want to talk to someone familiar with machining and bicycles... perhaps
    Longbikes or Terracycle.

    OTOH- ask yourself how often you use the IPS system. If you think you can get away with captain-only
    freewheeling (that is, the captain could coast on his own, but the stoker would be forced to pedal
    when the captain pedaled) then you could replace the stoker cranks with standard, but shorter
    cranks. That's certainly the least expensive proposition.

    Jeff

  6. Thanks, Don. I just emailed them. Perry "Don" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Perry, I do not know if the DV is something unique or just uses regular tandem components. Maybe
    what I am posting is useless to you. But hopefully it is not. St. John Street Cycles.
    sjscycles.comvIndex.htm has beautiful Thorn cranks for front and rear tandems
    140-175mm

    In the index do NOT look under cranksets. Look under "Chainsets" then "Tandem chainsets/cranks". I
    have a triple solo from them in 150mm and it is very nicely done. I picked the TA rings. Their
    polish matches the crank and they are ramped and pinned. Note which are marked outer, middle, and
    inner. Please note on pricing, US customers do not have to pay the value added tax so the listed
    price must be reduced by that amount. Also, when I ordered the arms, rings, and bolts I was
    promptly informed that what I ordered was considered a kit so they assembled it for me and greatly
    reduced the price. Delivered to my door in Sacramento from Jolly Olde in 9 days from my order.
    Nice chaps to deal with. Spot on and all that rot. Good luck. Don

  7. I run 145mm cranks on my trike and I'm a convert. Stopped my knee pain. Smoother and higher cadence.
    If it's all in the mind, it worked for me.

    MR now supply 155mm cranks on their Swiftlet S2.

    Paul W

  8. There is positively NO WAY I will ever give up IPS. Not until they pry my cold dead toes from my
    Frogs. With a big battleship hulking bike like the Double Vision, there are just too many needs for
    the IPS. Perry "Prints" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I run 145mm cranks on my trike and I'm a convert. Stopped my knee pain. Smoother and higher
    cadence. If it's all in the mind, it worked for me.

    MR now supply 155mm cranks on their Swiftlet S2.

    Paul W

  9. In article <[email hidden]>, Perry says...

    Quoted message said:


    There is positively NO WAY I will ever give up IPS. Not until they pry my cold dead toes from
    my Frogs.

    What a GREAT line to be overheard by somone who has no knowledge of cycling.

    "Just what were your toes doing on your Frogs?"

    Steve Christensen

  10. "Perry" <[email hidden]> wrote in message
    news:<[email hidden]>...

    Quoted message said:

    There is positively NO WAY I will ever give up IPS. Not until they pry my cold dead toes from my
    Frogs. With a big battleship hulking bike like the Double Vision, there are just too many needs
    for the IPS. Perry

    :-))

    If you're not going to give up IPS, then drilling and tapping the cranks is just about your only
    choice. It'll still require a good machinist to do the deed, but it's not terrible complex.

    They'll need to be shortened quite a bit, though, since enough material needs to be left on the
    outside of the pedal eye to keep them from cracking. You'll probably end up with 145mm or 150mm
    cranks, kind of like these cranks from DaVinci Designs: davincitandems.comxt3.jpg

    Mark Stonich has shortened cranks from a variety of sources: here's a little reading material:
    mnhpva.orgCrank.html bikesmithdesign.comDotek.html

    Jeff

  11. Perry, how about a set of crank shorteners from the Hostel shoppe? they would make the "Q" a little
    wider, but all in all, a less complicated and hassle free modification

    Perry said:

    Hi Earl, I do have IPS. (and I believe they're tapered) Why does that make a difference? Perry

    "Guess Who I Am" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Hello: if you donot have IPS or splined crank i know of a machine shop that will

    drill

    Quoted message said:

    and tap them out for you. if intrested please e-mail me back. Thank you Earl GRR,RANS V2 Ti
    Rush,Ti Pursuit

  12. "Jeff Wills" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    "Perry" <[email hidden]> wrote in message


    news:<[email hidden]>...

    Quoted message said:
    Quoted message said:

    There is positively NO WAY I will ever give up IPS. Not until they pry


    my

    Quoted message said:
    Quoted message said:

    cold dead toes from my Frogs. With a big battleship hulking bike like


    the

    Quoted message said:
    Quoted message said:

    Double Vision, there are just too many needs for the IPS. Perry

    :-))

    If you're not going to give up IPS, then drilling and tapping the cranks is just about your only
    choice. It'll still require a good machinist to do the deed, but it's not terrible complex.

    They'll need to be shortened quite a bit, though, since enough material needs to be left on the
    outside of the pedal eye to keep them from cracking. You'll probably end up with 145mm or 150mm
    cranks, kind of like these cranks from DaVinci Designs:
    davincitandems.comxt3.jpg

    Mark Stonich has shortened cranks from a variety of sources: here's a little reading material:
    mnhpva.orgCrank.html bikesmithdesign.comDotek.html

    I'm using a set of Mark's 155s drilled and tapped for triople rings. The crank and matching rings
    were about $150. He did a great job.

    I've never even seen an IPS-equipped bike, so I can't tell you if these cranks could be modified to
    work. I'm sure Mark knows, and could probably to the machining for you.

    Tom Thompson

  13. Just trying to learn something here. Is the IPS integral to the crank? Meaning you buy it all
    together and have limited choice on crank length. Don

  14. "Tom Thompson" <[email hidden]> wrote in message
    news:<[email hidden]>...

    Quoted message said:

    "Jeff Wills" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    "Perry" <[email hidden]> wrote in message


    news:<[email hidden]>...

    Quoted message said:
    Quoted message said:

    There is positively NO WAY I will ever give up IPS. Not until they pry


    my

    Quoted message said:
    Quoted message said:

    cold dead toes from my Frogs. With a big battleship hulking bike like


    the

    Quoted message said:
    Quoted message said:

    Double Vision, there are just too many needs for the IPS. Perry

    Quoted message said:

    :-))

    If you're not going to give up IPS, then drilling and tapping the cranks is just about your only
    choice. It'll still require a good machinist to do the deed, but it's not terrible complex.

    They'll need to be shortened quite a bit, though, since enough material needs to be left on the
    outside of the pedal eye to keep them from cracking. You'll probably end up with 145mm or 150mm
    cranks, kind of like these cranks from DaVinci Designs:
    davincitandems.comxt3.jpg

    Mark Stonich has shortened cranks from a variety of sources: here's a little reading material:
    mnhpva.orgCrank.html bikesmithdesign.comDotek.html

    I'm using a set of Mark's 155s drilled and tapped for triople rings. The crank and matching rings
    were about $150. He did a great job.

    I've never even seen an IPS-equipped bike, so I can't tell you if these cranks could be modified
    to work. I'm sure Mark knows, and could probably to the machining for you.

    Tom Thompson

    Some 175s can be retapped to 152s if there is enough material around the new hole. Usually there is
    not. I wouldn't use IPS if it was free, had no extra parts to fail, and didn't add weight.
    Especially if the alternative was an end to knee pain.

  15. [email hidden] (Don) wrote in message news:<[email hidden]>...

    Quoted message said:

    Just trying to learn something here. Is the IPS integral to the crank? Meaning you buy it all
    together and have limited choice on crank length. Don

    Yes. Vision's Independent Pedaling System inserts a freewheel mechanism between the crankarms and
    the chainrings on both the captain's and the stoker's cranksets. That way either rider can pedal or
    coast at their pleasure.

    Jeff

  16. Jeff Wills said:

    Yes. Vision's Independent Pedaling System inserts a freewheel mechanism between the crankarms and
    the chainrings on both the captain's and the stoker's cranksets. That way either rider can pedal
    or coast at their pleasure.

    Shades of the Shimano FF (Front Freewheel) system of the '70s. However, the only FF bike I ever
    rode, a 1977 Schwinn Caliente that I used to use, had permanently integrated chainrings and
    Ashtabula-style crankarms and BB. It was basically a Varsity with a fancy drivetrain; it also had
    the Positron rear mech, Shimano's first attempt at indexed shifting.

    FF also had an oddball cluster with a one-way slip clutch on each sprocket, in case the chain
    jammed. A flange on the cluster had a stamped warning that it was for use only with FF.

    With FF+Positron, you could shift at any time, but starting off was awkward if you downshifted while
    stopped. The Positron also used a solid shift cable, which tended to break from fatigue, either at
    the shifter or at the derailleur. One of today's 7- or 8-speed gearhubs with a conventional crank
    would be much better from a shift-at-any-time standpoint. I'm surprised, though, that Shimano never
    thought of using the FF cranks for tandem IPS, whether or not the funky cluster was used.

    I still have the old Schwinn, but damage/rust on a seat stay and worn-out teeth on the big ring have
    made it unsafe to ride.
    --
    Russ [email hidden] the wabbit to despam "No, see, it's not something
    you 'experience' - it's something that you posess. You know, that fine 'recumbent butt' - a
    distinguishing characterisitic of a recumbent cyclist." -Geoff Adams, on 'BROL

  17. Russ Price <[email hidden]> wrote in message
    news:<pzkob.65809$Tr4.183512@attbi_s03>...

    Quoted message said:
    Jeff Wills said:

    Yes. Vision's Independent Pedaling System inserts a freewheel mechanism between the crankarms
    and the chainrings on both the captain's and the stoker's cranksets. That way either rider can
    pedal or coast at their pleasure.

    Shades of the Shimano FF (Front Freewheel) system of the '70s. However, the only FF bike I ever
    rode, a 1977 Schwinn Caliente that I used to use, had permanently integrated chainrings and
    Ashtabula-style crankarms and BB. It was basically a Varsity with a fancy drivetrain; it also had
    the Positron rear mech, Shimano's first attempt at indexed shifting.

    Not quite- the Calientes of that era had "Positron II". The original Positron (that was never used
    on Schwinns, AFAIK) used a dual-cable system with indexing at the derailleur.

    You're right about the IPS being similar to the Front Freewheel system- almost exactly the
    same, in fact.

    <snip>

    Quoted message said:

    I still have the old Schwinn, but damage/rust on a seat stay and worn-out teeth on the big ring
    have made it unsafe to ride.

    So go buy an old Varsity and swap out the drivetrain. It all interchanges. Old Schwinns never die-
    they're tougher than cockroaches.

    Jeff Wills (Schwinn mechanic 1979-1984)

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