7 speed freewheel hubs on narrower dropouts sans freewheel

Discussion in 'Cycling Equipment' started by meb, Feb 28, 2004.

  1. meb

    meb New Member

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    Anyone know what width are typical freewheel hubs without the freewheel?

    I know it sounds funny, but there’s a method to my madness. I’m considering installing a regenerative braking rear electric hub motor on a recumbent front fork and maintaining the original rear on the bent. The hub receives a freewheel rather than freehub so the freewheel hub sans freewheel will be narrower than a freehub. With freewheel, it will fit on 126 mm rear dropouts. The manufacture’s contact says just adjust the nuts apparently not understanding you’re also minimum width limited by the width of the hub as to what will fit between the fork dropouts. No US dealers on this yet that I could get some measurements from.

    I’ve measured some BMX flip-flops at 107mm, but I’m not sure how they compare in width to multispeed freewheel hubs.
     
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  2. meb wrote:

    > Anyone know what width are typical freewheel hubs without the freewheel?

    5-speed ones are 120mm, more recent 6 speed ones are usually 126mm, and you might find wider because
    some mountain bike hubs can take freewheels. In most cases a 126mm hub can be taken down to 120mm
    very easily by removing and rearranging spacers.
     
  3. "meb" <[email protected]> wrote:

    > Anyone know what width are typical freewheel hubs without the freewheel?

    [snip]

    > I’ve measured some BMX flip-flops at 107mm, but I’m not sure how they compare in width to
    > multispeed freewheel hubs.

    By removing all unnecessary spacers and keyed washers from an old (1973) Campag record freewheel
    hub, I was able to reduce the width to 113mm across the locknuts. By replacing the thick locknuts
    with thinner ones from a contemporary track hub, it would be possible to reduce this to 103mm. For
    your application, you might be able to bond one cone permanently to the axle and dispense with its
    locknut to further reduce the width. The bare shell measures 89mm from dustcap to dustcap.

    Exactly how narrow it's possible to make your hub will depend on its exact dimensions. You'll need
    to remove the freewheel and take some measurements.

    James Thomson
     
  4. Mike S.

    Mike S. Guest

    "Zog The Undeniable" <[email protected]> wrote in message
    news:[email protected]...
    > meb wrote:
    >
    > > Anyone know what width are typical freewheel hubs without the freewheel?
    >
    > 5-speed ones are 120mm, more recent 6 speed ones are usually 126mm, and you might find wider
    > because some mountain bike hubs can take freewheels. In most cases a 126mm hub can be taken down
    > to 120mm very easily by removing and rearranging spacers.

    I think you misunderstood the question Zog.

    FWI understand, he's asking how wide the hub shell is so he can respace the axle to run a FW rear
    hub on the front wheel.

    If that's correct, the only FW hub I have is an American Classic which is slightly different than
    most. The hub shell itself is 8cm wide. If you find a machine shop you can have the end caps turned
    down to make whatever size spacing you want.

    I had a client/machine shop owner turn down one end cap for me to run an Am
    Cl. hub on my 120mm track bike.

    That help?

    Mike
     
  5. Werehatrack

    Werehatrack Guest

    On Sun, 29 Feb 2004 05:50:29 GMT, meb <[email protected]>
    may have said:

    >Anyone know what width are typical freewheel hubs without the freewheel?

    For a meaningful answer, consider that the "typical" freewheel hub's charactistics are irrelevant,
    since you won't be dealing with a typical freewheel hub at all. The mere fact that the hub you
    propose to install can use a freewheel does not imply that it is typical in any other respect.

    Ask the manufacturer what range of hub widths can be achieved by removal and/or rearrangement
    of spacers.

    --
    My email address is antispammed; pull WEEDS if replying via e-mail.
    Typoes are not a bug, they're a feature.
    Words processed in a facility that contains nuts.
     
  6. meb

    meb New Member

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    That’s sounds encouraging.

    There no incentive to go much below 100mm since that’s the front fork I’d be trying to put it on, although I’d go with a wider fork if necessary. Those ideas on the lockwashers and track cones could help, particularly if the manufacturer hasn’t already resorted to that to fit the 7 speed units within the 126mm dropouts.

    I’m certainly going to be slightly limited by the washers and cones left.
    I’d like to have this as a quick change interchangeable front wheel with nonelectric front wheel, so permanently mounting the fork with a cone only works if I sacrifice quick change and swap out forks when I switch between electric and nonelectric rides.

    Left side phots show an annular ring extending left of the dust cap around the cone nuts, so probably can’t much more than a couple of mm on the left side. I’d estimate the ring extends 10mm left of the dustcovers. The big narrowing from 126mm would likely be on the right side with the elimination of the protruding freewheel, and subsequent nut spacer reduction per your suggestion.

    There are two other manufactures with lighter front hubs with regenerative braking potentially available soon-although one has "front hub" dimensions that won’t fit common US front forks either.

    Thanks
     
  7. meb

    meb New Member

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    Mike S. you’ve got the general idea.

    With this regenerative hub-right side I’m going to be limited by the threads or dustcovers and an annular ring attached to the shell left side.

    Zog: 120/126mm are the dropout width’s the hubs WITH FREEWHEEL and spacers and nuts fit between.
    The 7 speed freewheel extends right of the hub body, spacers and cones normally extend well left of the body.


    Thanks
     
  8. meb

    meb New Member

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    I see your point, since I haven’t seen a bare right side photo sans freewheel, its width isn’t necessarily limited to the normal max width limits with these folks cramming the electrical components in that hub coupled to a 7 speed freewheel-all inside 126mm dropouts-the body might very well protrude beyond the cones or threads on the right side. I have photos of the left, so I can see it differs only from a standard freewheel hub with respect to a protruding annular ring..

    At the moment this looks like this is the best hub/motor/generator likely available for a trike I’m scratch-building with sprockets and hubmotor together on the same wheel. The trike drive hub sizing is not critical, but the non-immediate need gives me time to wait and see if something better comes available. If I new this would fit a bike front fork, I’d order now with the idea of later transferring this to the trike. Else I’ wait till proximate the trike need date. The bike vs. trike wheels are 349 vs. 700 so this would not be a simple swap between two dropouts.

    Getting info from this manufacturer’s customer relations contact is like pulling teeth.
     
  9. Doug Goncz

    Doug Goncz Guest

    >Getting info from this manufacturer’s customer relations contact is like pulling teeth.
    >
    >

    Kollmorgen?

    My physics project at NVCC: Google Groups, then "dgoncz" and some of: ultracapacitor bicycle
    fluorescent flywheel inverter
     
  10. meb

    meb New Member

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    No-foreign.

    EPS-Systems not yet marketing to the US.
    Available through several Canadian dealers advertising with both US and Canadian $.
     
  11. Jeff Wills

    Jeff Wills Guest

    > By removing all unnecessary spacers and keyed washers from an old (1973) Campag record freewheel
    > hub, I was able to reduce the width to 113mm across the locknuts. By replacing the thick locknuts
    > with thinner ones from a contemporary track hub, it would be possible to reduce this to 103mm. For
    > your application, you might be able to bond one cone permanently to the axle and dispense with its
    > locknut to further reduce the width. The bare shell measures 89mm from dustcap to dustcap.
    >
    > Exactly how narrow it's possible to make your hub will depend on its exact dimensions. You'll need
    > to remove the freewheel and take some measurements.
    >
    > James Thomson

    I think James has answered your question, meb, but you'll also have to file the dropouts or turn
    down the axle- the axle in that hub may be larger diameter than a "typical" front axle.

    Sounds like a fun project, though!

    Jeff
     
  12. A Muzi

    A Muzi Guest

    >>>meb wrote: Anyone know what width are typical freewheel hubs without the freewheel?

    > "Zog The Undeniable" <[email protected]> wrote in message news:[email protected]...
    >>5-speed ones are 120mm, more recent 6 speed ones are usually 126mm, and you might find wider
    >>because some mountain bike hubs can take freewheels. In most cases a 126mm hub can be taken down
    >>to 120mm very easily by removing and rearranging spacers.

    Mike S. wrote:
    > I think you misunderstood the question Zog. FWI understand, he's asking how wide the hub shell is
    > so he can respace the axle to run a FW rear hub on the front wheel. If that's correct, the only FW
    > hub I have is an American Classic which is slightly different than most. The hub shell itself is
    > 8cm wide. If you find a machine shop you can have the end caps turned down to make whatever size
    > spacing you want. I had a client/machine shop owner turn down one end cap for me to run an Am
    > Cl. hub on my 120mm track bike.

    Oh, that's an intriguing analysis.

    If you're right, and that's what the OP is asking, a practical answer is that most freewheel hubs,
    certainly the bulk of standard inexpensive models, do have a spacer on the right side of the axle
    which may be removed, or substituted for a slimmer piece, to attain the 100 mm width of a fork.

    That being said, you still won't have any extra room! To do this, you'll need to remove all spacers
    and washers. Even then, most brands will require thinner than standard locknuts to reach 100 mm. In
    some cases (some Jo You, some Sovos and Shimano 7300 early DuraAce come to mind) the length of the
    cone itself will push you beyond 100 mm before you add locknuts at all.

    You don't say why you want to do this (in fact, this is still conjecture - did you, dear OP, really
    intend that?) but taking this on its face, I would not panic over a couple of millimeters variance.
    Just get it as close as possible with reasonable effort and pull the fork open when you slide your
    106mm hub into the 100mm space.

    In for a penny, in for a pound:

    Rear hub flanges are closer to one side than the other, even after you change the axle spacing. To
    center the rim over the locknuts,* flip it frequently in your fixture ( fork or truing stand) while
    straightening the rim.

    Not all bike forks are 100mm. Raleigh Nottingham forks were 95mm, including Phillips, RoyalScot etc.
    That's not just arcana - I mention it here because the A-line versions of these bikes are still
    sought after as commuters- they come with the best mudguards ever.

    Forks are made for 9mm quick release or 8mm solid axles. Rear freewheel hubs use 9.5 solid or 10mm
    quick release axles. If you slip a 14 or 15mm wrench in the axle slot and prise gently, it will open
    enough. That will leave you with an ugly end. Cutting with a file or a rotary air file is better.
    But only cut the sides of the slot - leave paint at the top so you do not change the fork alignment.

    Knowing all that, you might save yourself a lot of trouble by swapping your extra rear wheel with
    someone for a front wheel.

    *Front wheels should be symmetric such that any front wheel can mount in any modern fork mounted
    either way.

    --
    Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971n
     
  13. meb

    meb New Member

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    How about downsizing the hub/motor axle since there would be little weight on it?

    Thanks
     
  14. meb

    meb New Member

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    Yes I did mean that.

    The idea is that when one is clipping along at 25-30 mph on the flats or on a downhill, to charge up some small lightweight NiMH batteries and 250W motor to avoid those 4-6 mph recumbent hill climbs. Not all my trips are hilly, so it'd be nice to have quick swap out front hubs to change configurations and save the weight. If used as an interchangeable rear freewheel drive, I'd need contend with deraileur, dual drive loss, and lack of cassette configuration control. The cassette configuration control is more significant on a bent since you spend so much time well above electric speeds.

    I'll get better weight distribution adding the weight up front, and it'd be easier to unhook the batterybox and wiring quickly up front than in the back.

    When you said fit the 106mm hub in the 100mm fork, are you suggesting that the measurements James had were on an atypically sized freewheel hub or that is merely the target width I need to downsize to for spreading the front fork?


    Thanks
     
  15. meb

    meb New Member

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    Jeff

    By turn down the axles did you mean grind down the axle diameters at the dropout distance to front axle diameter?

    Thanks
     
  16. A Muzi

    A Muzi Guest

    meb wrote:

    > When you said fit the 106mm hub in the 100mm fork, are you suggesting that the measurements James
    > had were on an atypically sized freewheel hub or that is merely the target width I need to
    > downsize to for spreading the front fork?
    >
    I just meant that some rear hubs can't easily get to 100mm given the available locknuts. Try for 100mm-
    but slipping a slightly wider hub in a fork is OK.

    --
    Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971
     
  17. Doug Goncz

    Doug Goncz Guest

    Sanyo has a 200W brushless motor that would be ideal for regenerative braking with a three phase
    full wave rectifier. Tom Nakamura in Chicago is coordinating. Rabbittool on the web advertises but
    never delivers. I'm still trying.

    My approach is to generate power at the pedal with a large, low speed servo motor chain driven from
    a left side tandem crank. I may add a wheel driven motor in the center of the frame diamond. It's
    hard work.

    I generated over 40W with such a setup on a wheel driven motor, but got scared. A BMX spider on a
    flip flop hub or a Big Cheese, bored out and drilled, on a cassette hub, drives the motor with a
    long bit of bicycle chain. But I like the pedal drive cause the CG is low, as it will be in your
    front wheel.

    Kollmorgen's Power Trac will fit front wheels, I think, with the freewheel off.

    The Sanyo is brushless, but geared, and sensorless (self-sensing controller) It is the controller
    that is delaying the project.

    TI will provide samples of efficient DC-DC converters if needed. You just register. I have a 6V for
    my headlight and taillight at 1.5A, and a 15V for my inverter at 5A.

    My physics project at NVCC: Google Groups, then "dgoncz" and some of: ultracapacitor bicycle
    fluorescent flywheel inverter
     
  18. Dvt

    Dvt Guest

    A Muzi wrote:

    > meb wrote:
    >
    >> When you said fit the 106mm hub in the 100mm fork, are you suggesting that the measurements James
    >> had were on an atypically sized freewheel hub or that is merely the target width I need to
    >> downsize to for spreading the front fork?
    >>
    > I just meant that some rear hubs can't easily get to 100mm given the available locknuts. Try for
    > 100mm- but slipping a slightly wider hub in a fork is OK.
    >

    meb, I suspect that Andy is talking about upright bike forks rather than the smaller forks of a
    "typical" 'bent. So if Andy says you can squeeze a 106mm hub into a 100mm fork, you might want to
    scale down a bit to account for the shorter fork legs.

    --
    Dave dvt at psu dot edu
     
  19. meb

    meb New Member

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    Doug:

    Sanyo was one of the two lighter weight competitors with front hubs I was anticipating having a regenerative braking motor/hub this spring/summer. They were having some new 250W & 500W brushless DC units, both sensored and unsensored.units available. They were having some problem coming to market, but still were displaying their units two months ago at the Tokyo show. Their 250W sensored motor is my preferred option if it comes available. The motor controller problems you identified as the source of their delay further has me thinking about not waiting if we are talking about the same units (the difference in power we are citing has me wondering). Are the 200W units you referred to set up for regenerative braking or merely adaptable to such change.

    Rabbittools’ single sprocket 500W wide rear hub motor is too much of a slow speed motor first, pedal secondary device for me. Doesn’t leave a lot of options to shift to higher/lower ratios as needed unless one adds a complicated middrive. Also, since they are groundbreaking with the AC motors, I expect it will take longer for them to have a reliable controller vs. the more developed brushless DC controllers which have substantially had the bugs resolved by now. One would not have any prayer of fitting that wide motor-hub in a front fork.

    I wasn’t ware of Kollmorgen having any units set up for regenerative braking, nor was I aware they made hub motors. Have they something with either or both of these features?
     
  20. Dvt

    Dvt Guest

    meb wrote:

    > Anyone know what width are typical freewheel hubs without the freewheel?

    Sounds like a cool project. I'd walk to the local junkyard, pick up an old freewheel hub, and
    experiment. Or visit the LBS junk bin.

    --
    Dave dvt at psu dot edu
     
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