Linear-drive bicycles - home-building?

[DougC]

I am curious about building a linear-drive bicycle.
I hadn't bothered much with the idea because I didn't know how to build
the freewheeling mechanisms, but lately I've found out that I don't
/need/ to build them, single-speed freewheel cogs are already available
from Shimano for roughly $10 each.

I have no idea how these would be used with anything else however. Are
there any websites showing someone constructing a similar drive vehicle
with them?
~

 

[A Muzi]

DougC wrote:
> I am curious about building a linear-drive bicycle.
> I hadn't bothered much with the idea because I didn't know how to build
> the freewheeling mechanisms, but lately I've found out that I don't
> /need/ to build them, single-speed freewheel cogs are already available
> from Shimano for roughly $10 each.
>
> I have no idea how these would be used with anything else however. Are
> there any websites showing someone constructing a similar drive vehicle
> with them?

Linear drive? Like a "rail gun"?? Sounds fast.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[Kerry Montgomery]

"DougC" <[email protected]> wrote in message
news:[email protected]...
>I am curious about building a linear-drive bicycle.
> I hadn't bothered much with the idea because I didn't know how to build
> the freewheeling mechanisms, but lately I've found out that I don't /need/
> to build them, single-speed freewheel cogs are already available from
> Shimano for roughly $10 each.
>
> I have no idea how these would be used with anything else however. Are
> there any websites showing someone constructing a similar drive vehicle
> with them?
> ~

DougC,
I think Carl Fogel has posted photos of this type of drive, but here is a
diagram:
http://www.geometricbikes.com/images/how-it-works_big.jpg
Kerry

 

[[email protected]]

On Mon, 15 Oct 2007 18:11:59 -0500, A Muzi <[email protected]>
wrote:

>DougC wrote:
>> I am curious about building a linear-drive bicycle.
>> I hadn't bothered much with the idea because I didn't know how to build
>> the freewheeling mechanisms, but lately I've found out that I don't
>> /need/ to build them, single-speed freewheel cogs are already available
>> from Shimano for roughly $10 each.
>>
>> I have no idea how these would be used with anything else however. Are
>> there any websites showing someone constructing a similar drive vehicle
>> with them?
>
>Linear drive? Like a "rail gun"?? Sounds fast.

Dear Andrew,

Possibly treadle-drive?

http://americanhistory.si.edu/ONTHEMOVE/collection/object_282.html

http://americanhistory.si.edu/ONTHEMOVE/collection/object_283.html

http://americanhistory.si.edu/ONTHEMOVE/collection/object_294.html


Cheers,

Carl Fogel

 

[[email protected]]

On Mon, 15 Oct 2007 17:10:19 -0700, "Kerry Montgomery"
<[email protected]> wrote:

>
>"DougC" <[email protected]> wrote in message
>news:[email protected]...
>>I am curious about building a linear-drive bicycle.
>> I hadn't bothered much with the idea because I didn't know how to build
>> the freewheeling mechanisms, but lately I've found out that I don't /need/
>> to build them, single-speed freewheel cogs are already available from
>> Shimano for roughly $10 each.
>>
>> I have no idea how these would be used with anything else however. Are
>> there any websites showing someone constructing a similar drive vehicle
>> with them?
>> ~
>
>DougC,
>I think Carl Fogel has posted photos of this type of drive, but here is a
>diagram:
>http://www.geometricbikes.com/images/how-it-works_big.jpg
>Kerry

Dear Kerry,

Possibly the Lattimer?

http://i9.tinypic.com/4taqys4.jpg

Cheers,

Carl Fogel

 

[[email protected]]

Kerry Montgomery writes:

>> I am curious about building a linear-drive bicycle. I hadn't
>> bothered much with the idea because I didn't know how to build the
>> freewheeling mechanisms, but lately I've found out that I don't
>> /need/ to build them, single-speed freewheel cogs are already
>> available from Shimano for roughly $10 each.

....except that they are right handed and work only on the right side.

>> I have no idea how these would be used with anything else
>> however. Are there any websites showing someone constructing a
>> similar drive vehicle with them? ~

> I think Carl Fogel has posted photos of this type of drive, but here
> is a diagram:

> http://www.geometricbikes.com/images/how-it-works_big.jpg

This is the mechanism Alenax all over again. This bicycle was at
InterBike again this year but with independent rotary cranks. That
is, each crank had a roller clutch (freewheel) so that they were not
phased to one another as conventional bicycle cranks are (180°) apart.

This got them over the step-function from zero to crank speed at the
ends of the stroke (if pedaling continuously) but it did not get them
over the both-pedals-to-the-bottom effect when standing up, which did
not raise the rider from the saddle (unless it was too low).

http://www.sheldonbrown.com/brandt/alenax.html

That all machinery that converts linear to circular motion uses cranks
should not overlook that reason. As In a piston engine, the legs also
have a finite stroke and inertia, so sinusoidal motion of a crank is
ideal. A linear pedal is exactly the opposite from what the device
needs.

Jobst Brandt

 

[Nate Knutson]

On Oct 15, 5:10 pm, "Kerry Montgomery" <[email protected]> wrote:
> "DougC" <[email protected]> wrote in message
>
> news:[email protected]...
>
> >I am curious about building a linear-drive bicycle.
> > I hadn't bothered much with the idea because I didn't know how to build
> > the freewheeling mechanisms, but lately I've found out that I don't /need/
> > to build them, single-speed freewheel cogs are already available from
> > Shimano for roughly $10 each.
>
> > I have no idea how these would be used with anything else however. Are
> > there any websites showing someone constructing a similar drive vehicle
> > with them?
> > ~
>
> DougC,
> I think Carl Fogel has posted photos of this type of drive, but here is a
> diagram:http://www.geometricbikes.com/images/how-it-works_big.jpg
> Kerry

if this kind of thing is what the OP had in mind, and all that's
needed for the hub and cogs is basically 2 same-size freewheels whose
mechanisms mirror each other on either side of the hub, you could use
a bmx flipflop hub with left drive on one side and right on the other.
i'm pretty sure i've seen metric/metric ones like this, which isn't
optimal because the cog size would be limited to 13t. assuming they
exist, they were always pretty uncommon, and it will be hard to find a
quality one in good shape now. metric/normal with the metric side
leftdrive is very common, but you need the same size cog so that's no
good. you could also turn one of these to be metric/metric, which
might be a decent plan since it's currently easy enough to get a new,
good one. ideal would be normal/normal, but i'm not sure that exists
with a leftdrive/rightdrive split, although 16t leftdrive freewheels
do exist. i'm sure phil could also easily make you a normal/normal
left/right drive ff hub, if it's budgetable. that way it wouldn't have
to be 14mm, too.

 

[[email protected]]

On 16 Oct 2007 00:41:12 GMT, [email protected] wrote:

>Kerry Montgomery writes:
>
>>> I am curious about building a linear-drive bicycle. I hadn't
>>> bothered much with the idea because I didn't know how to build the
>>> freewheeling mechanisms, but lately I've found out that I don't
>>> /need/ to build them, single-speed freewheel cogs are already
>>> available from Shimano for roughly $10 each.
>
>...except that they are right handed and work only on the right side.

[snip]

Dear Jobst,

Luckily, you can get left and right versions of single-speed freewheel
in the BMX world.

As has been previously discussed, there are _two_ sides to this issue:

http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44

The link in that post to left-side freewheels has died.

So here's a page that shows the normal (right-side) ACS single-speed
freewheel and the abnormal (left-side) ACS single-speed South-Paw
claw:


http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62

,sreehC

Carl Fogel

 

[[email protected]]

Carl Fogel writes:

>>>> I am curious about building a linear-drive bicycle. I hadn't
>>>> bothered much with the idea because I didn't know how to build the
>>>> freewheeling mechanisms, but lately I've found out that I don't
>>>> /need/ to build them, single-speed freewheel cogs are already
>>>> available from Shimano for roughly $10 each.

>>...except that they are right handed and work only on the right side.

> Luckily, you can get left and right versions of single-speed freewheel
> in the BMX world.

> As has been previously discussed, there are _two_ sides to this issue:

http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44

> The link in that post to left-side freewheels has died.

> So here's a page that shows the normal (right-side) ACS single-speed
> freewheel and the abnormal (left-side) ACS single-speed South-Paw
> claw:

http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=310&idParent=62

http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62

Well you'll need a hub with left hand threads on the left side. I
suppose those must be around or they wouldn't make freewheels for
them.

Jobst Brandt

 

[[email protected]]

On 16 Oct 2007 01:46:22 GMT, [email protected] wrote:

>Carl Fogel writes:
>
>>>>> I am curious about building a linear-drive bicycle. I hadn't
>>>>> bothered much with the idea because I didn't know how to build the
>>>>> freewheeling mechanisms, but lately I've found out that I don't
>>>>> /need/ to build them, single-speed freewheel cogs are already
>>>>> available from Shimano for roughly $10 each.
>
>>>...except that they are right handed and work only on the right side.
>
>> Luckily, you can get left and right versions of single-speed freewheel
>> in the BMX world.
>
>> As has been previously discussed, there are _two_ sides to this issue:
>
> http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>
>> The link in that post to left-side freewheels has died.
>
>> So here's a page that shows the normal (right-side) ACS single-speed
>> freewheel and the abnormal (left-side) ACS single-speed South-Paw
>> claw:
>
> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=310&idParent=62
>
> http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62
>
>Well you'll need a hub with left hand threads on the left side. I
>suppose those must be around or they wouldn't make freewheels for
>them.
>
>Jobst Brandt

Dear Jobst,

Yes, they do make hubs for the left-hand drive freewheel:


http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=258&idParent=96

But I'd be surprised if they make a hub that's dual-sided.

That is, you can get a left (abnormal) or a right (normal), but
probably not both together.

Maybe you could buy one of each and combine parts, but I suspect that
such weird hubs are probably made from scratch by tricking someone
like Chalo into running his lathe at midnight while uttering the
Lord's Prayer backwards.

Cheers,

Carl Fogel

 

[DougC]

[email protected] wrote:
> On 16 Oct 2007 01:46:22 GMT, [email protected] wrote:
>
>> Carl Fogel writes:
>>
>>>>>> I am curious about building a linear-drive bicycle. I hadn't
>>>>>> bothered much with the idea because I didn't know how to build the
>>>>>> freewheeling mechanisms, but lately I've found out that I don't
>>>>>> /need/ to build them, single-speed freewheel cogs are already
>>>>>> available from Shimano for roughly $10 each.
>>>> ...except that they are right handed and work only on the right side.
>>> Luckily, you can get left and right versions of single-speed freewheel
>>> in the BMX world.
>>> As has been previously discussed, there are _two_ sides to this issue:
>> http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>>
>>> The link in that post to left-side freewheels has died.
>>> So here's a page that shows the normal (right-side) ACS single-speed
>>> freewheel and the abnormal (left-side) ACS single-speed South-Paw
>>> claw:
>> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=310&idParent=62
>>
>> http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCategory=322&idParent=62
>>
>> Well you'll need a hub with left hand threads on the left side. I
>> suppose those must be around or they wouldn't make freewheels for
>> them.
>>
>> Jobst Brandt
>
> Dear Jobst,
>
> Yes, they do make hubs for the left-hand drive freewheel:
>
>
> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProduct=258&idParent=96
>
> But I'd be surprised if they make a hub that's dual-sided.
>
> That is, you can get a left (abnormal) or a right (normal), but
> probably not both together.
>
> Maybe you could buy one of each and combine parts, but I suspect that
> such weird hubs are probably made from scratch by tricking someone
> like Chalo into running his lathe at midnight while uttering the
> Lord's Prayer backwards.
>
> Cheers,
>
> Carl Fogel
>
>

I don't want to fix the two "added" freewheels to both sides of the rear
wheel at all. What I'm imagining is a way to functionally place them on
a jackshaft, and then use the jackshaft to spin a conventional BB
somehow--such as by using another cog and chain over the granny ring.

This would be for a recumbent bike anyway, so the added drivetrain
length wouldn't be a problem. I've only see this on a couple of IHPVA
type streamliner recumbents--and not any of the current ones, so I don't
suspect it's going to result in a higher power output.

I am quite intrigued by a drivetrain that lets you use whatever stroke
you wish. I suspect it would make the bicycle much less fit-critical,
and may end up being more comfortable in use.
~

 

[Nate Knutson]

On Oct 15, 7:11 pm, [email protected] wrote:
> On 16 Oct 2007 01:46:22 GMT, [email protected] wrote:
>
>
>
> >Carl Fogel writes:
>
> >>>>> I am curious about building a linear-drive bicycle. I hadn't
> >>>>> bothered much with the idea because I didn't know how to build the
> >>>>> freewheeling mechanisms, but lately I've found out that I don't
> >>>>> /need/ to build them, single-speed freewheel cogs are already
> >>>>> available from Shimano for roughly $10 each.
>
> >>>...except that they are right handed and work only on the right side.
>
> >> Luckily, you can get left and right versions of single-speed freewheel
> >> in the BMX world.
>
> >> As has been previously discussed, there are _two_ sides to this issue:
>
> >http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>
> >> The link in that post to left-side freewheels has died.
>
> >> So here's a page that shows the normal (right-side) ACS single-speed
> >> freewheel and the abnormal (left-side) ACS single-speed South-Paw
> >> claw:
>
> >http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> >http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCat...
>
> >Well you'll need a hub with left hand threads on the left side. I
> >suppose those must be around or they wouldn't make freewheels for
> >them.
>
> >Jobst Brandt
>
> Dear Jobst,
>
> Yes, they do make hubs for the left-hand drive freewheel:
>
> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> But I'd be surprised if they make a hub that's dual-sided.

they are common. much more common than either single-sided or left/
left freewheel hubs, as numerous bikes come oem with them.

http://en.wikipedia.org/wiki/Flip-flop_hub

one thing this article perhaps has wrong is saying that the 16t
southpaw is the most common leftdrive fw. in actuality it's probably
the ody 13t, ime.

 

[[email protected]]

On Mon, 15 Oct 2007 20:43:57 -0700, Nate Knutson <[email protected]>
wrote:

>On Oct 15, 7:11 pm, [email protected] wrote:
>> On 16 Oct 2007 01:46:22 GMT, [email protected] wrote:
>>
>>
>>
>> >Carl Fogel writes:
>>
>> >>>>> I am curious about building a linear-drive bicycle. I hadn't
>> >>>>> bothered much with the idea because I didn't know how to build the
>> >>>>> freewheeling mechanisms, but lately I've found out that I don't
>> >>>>> /need/ to build them, single-speed freewheel cogs are already
>> >>>>> available from Shimano for roughly $10 each.
>>
>> >>>...except that they are right handed and work only on the right side.
>>
>> >> Luckily, you can get left and right versions of single-speed freewheel
>> >> in the BMX world.
>>
>> >> As has been previously discussed, there are _two_ sides to this issue:
>>
>> >http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>>
>> >> The link in that post to left-side freewheels has died.
>>
>> >> So here's a page that shows the normal (right-side) ACS single-speed
>> >> freewheel and the abnormal (left-side) ACS single-speed South-Paw
>> >> claw:
>>
>> >http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>>
>> >http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCat...
>>
>> >Well you'll need a hub with left hand threads on the left side. I
>> >suppose those must be around or they wouldn't make freewheels for
>> >them.
>>
>> >Jobst Brandt
>>
>> Dear Jobst,
>>
>> Yes, they do make hubs for the left-hand drive freewheel:
>>
>> http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>>
>> But I'd be surprised if they make a hub that's dual-sided.
>
>they are common. much more common than either single-sided or left/
>left freewheel hubs, as numerous bikes come oem with them.
>
>http://en.wikipedia.org/wiki/Flip-flop_hub
>
>one thing this article perhaps has wrong is saying that the 16t
>southpaw is the most common leftdrive fw. in actuality it's probably
>the ody 13t, ime.

Dear Nate,

You're right and I'm wrong (or at least surprised).

I was just flat mistaken about the threading on the flip-flop. I
assumed that it was the same on both sides, but the article that you
link to says no, opposite threading.

What I overlooked (I think) is that one gear is fixed (probably the
lower for climbing) and the other freewheels (probably the higher for
coasting on descents and flats), so unscrewing would be a problem.

Thanks for surprising me!

Cheers,

Carl Fogel

 

[JeffWills]

On Oct 15, 1:20 pm, DougC <[email protected]> wrote:
> I am curious about building a linear-drive bicycle.
> I hadn't bothered much with the idea because I didn't know how to build
> the freewheeling mechanisms, but lately I've found out that I don't
> /need/ to build them, single-speed freewheel cogs are already available
> from Shimano for roughly $10 each.
>
> I have no idea how these would be used with anything else however. Are
> there any websites showing someone constructing a similar drive vehicle
> with them?
> ~

Joe Kochanowski built a semi-linear drive recumbent, visible on this
page:
http://www.outsideconnection.com/gallant/hpv/joe/
with an action video at
http://www.outsideconnection.com/gallant/hpv/joe/linearDrive.mpg

There's also the "K-drive":
http://web.uct.ac.za/depts/psychology/bok/kdrive.html

Various forms of linear drives have been tried in human-powered
vehicle competitions over the years. None has been successful. All of
the vehicles at this year's World Human Powered Speed Challenge used a
circular crank motion, even if other drivetrain details were all over
the place.

Jeff

 

[Nate Knutson]

On Oct 15, 9:44 pm, [email protected] wrote:
> On Mon, 15 Oct 2007 20:43:57 -0700, Nate Knutson <[email protected]>
> wrote:
>
>
>
> >On Oct 15, 7:11 pm, [email protected] wrote:
> >> On 16 Oct 2007 01:46:22 GMT, [email protected] wrote:
>
> >> >Carl Fogel writes:
>
> >> >>>>> I am curious about building a linear-drive bicycle. I hadn't
> >> >>>>> bothered much with the idea because I didn't know how to build the
> >> >>>>> freewheeling mechanisms, but lately I've found out that I don't
> >> >>>>> /need/ to build them, single-speed freewheel cogs are already
> >> >>>>> available from Shimano for roughly $10 each.
>
> >> >>>...except that they are right handed and work only on the right side.
>
> >> >> Luckily, you can get left and right versions of single-speed freewheel
> >> >> in the BMX world.
>
> >> >> As has been previously discussed, there are _two_ sides to this issue:
>
> >> >http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>
> >> >> The link in that post to left-side freewheels has died.
>
> >> >> So here's a page that shows the normal (right-side) ACS single-speed
> >> >> freewheel and the abnormal (left-side) ACS single-speed South-Paw
> >> >> claw:
>
> >> >http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> >> >http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCat...
>
> >> >Well you'll need a hub with left hand threads on the left side. I
> >> >suppose those must be around or they wouldn't make freewheels for
> >> >them.
>
> >> >Jobst Brandt
>
> >> Dear Jobst,
>
> >> Yes, they do make hubs for the left-hand drive freewheel:
>
> >>http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> >> But I'd be surprised if they make a hub that's dual-sided.
>
> >they are common. much more common than either single-sided or left/
> >left freewheel hubs, as numerous bikes come oem with them.
>
> >http://en.wikipedia.org/wiki/Flip-flop_hub
>
> >one thing this article perhaps has wrong is saying that the 16t
> >southpaw is the most common leftdrive fw. in actuality it's probably
> >the ody 13t, ime.
>
> Dear Nate,
>
> You're right and I'm wrong (or at least surprised).
>
> I was just flat mistaken about the threading on the flip-flop. I
> assumed that it was the same on both sides, but the article that you
> link to says no, opposite threading.
>
> What I overlooked (I think) is that one gear is fixed (probably the
> lower for climbing) and the other freewheels (probably the higher for
> coasting on descents and flats), so unscrewing would be a problem.

fixed gears aren't involved (unless someone decides to be eccentric).
also, bmx riders generally don't use flipflop hubs for the sake of
having different gears to choose from. the benefit of a flipfop hub is
either that it can take both iso and metric in one drive orientation
(this is the most common), or so that it can be left/right with the
same thread size on both (but different handedness, of course), or so
that it can be a right/normal and left/metric split. in other words,
it might be chosen by the rider for versatility, by whoever's stocking
the wheel for it's ability to fill different needs, or by the bike
company (and industry as a whole) to provide an upgrade path (smaller
gearing, in the most common case of a normal/metric rh-drive flipflop
hub).

 

[DougC]

JeffWills wrote:

>
> Joe Kochanowski built a semi-linear drive recumbent, visible on this
> page:
> http://www.outsideconnection.com/gallant/hpv/joe/
> with an action video at
> http://www.outsideconnection.com/gallant/hpv/joe/linearDrive.mpg
>
> There's also the "K-drive":
> http://web.uct.ac.za/depts/psychology/bok/kdrive.html
>

Neither of these allows variable-length pedal strokes, however. They are
only variants based on conventional pedal cranks.

> Various forms of linear drives have been tried in human-powered
> vehicle competitions over the years. None has been successful. All of
> the vehicles at this year's World Human Powered Speed Challenge used a
> circular crank motion, even if other drivetrain details were all over
> the place.
>

Power output is not my particular goal, riding comfort is--though I
suspect that allowing variable-length strokes WOULD improve power output
for most average riders. When people jog over varied terrain, they do
not use the same stride length over all terrain, or even throughout the
total distance--but conventional bicycles force you to use the same
length of pedal stroke all the time.

The Sherer trike approaches what I'm imagining, except that I don't have
much interest in a trike, and I don't want to pay $4200+ for such a
setup either.

http://www.shererusa.com/page2.html

What I'm interested is how exactly those freewheels have to be attached
to function.
~

 

[[email protected]]

On Oct 16, 4:45 am, DougC <[email protected]> wrote:
> [email protected] wrote:
> > On 16 Oct 2007 01:46:22 GMT, [email protected] wrote:
>
> >> Carl Fogel writes:
>
> >>>>>> I am curious about building a linear-drive bicycle. I hadn't
> >>>>>> bothered much with the idea because I didn't know how to build the
> >>>>>> freewheeling mechanisms, but lately I've found out that I don't
> >>>>>> /need/ to build them, single-speed freewheel cogs are already
> >>>>>> available from Shimano for roughly $10 each.
> >>>> ...except that they are right handed and work only on the right side.
> >>> Luckily, you can get left and right versions of single-speed freewheel
> >>> in the BMX world.
> >>> As has been previously discussed, there are _two_ sides to this issue:
> >>http://groups.google.com/group/rec.bicycles.tech/msg/adfadf06467f4d44
>
> >>> The link in that post to left-side freewheels has died.
> >>> So here's a page that shows the normal (right-side) ACS single-speed
> >>> freewheel and the abnormal (left-side) ACS single-speed South-Paw
> >>> claw:
> >>http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> >>http://distro.1664bmx.com/comersus/store/comersus_listItems.asp?idCat...
>
> >> Well you'll need a hub with left hand threads on the left side. I
> >> suppose those must be around or they wouldn't make freewheels for
> >> them.
>
> >> Jobst Brandt
>
> > Dear Jobst,
>
> > Yes, they do make hubs for the left-hand drive freewheel:
>
> >http://distro.1664bmx.com/comersus/store/comersus_viewItem.asp?idProd...
>
> > But I'd be surprised if they make a hub that's dual-sided.
>
> > That is, you can get a left (abnormal) or a right (normal), but
> > probably not both together.
>
> > Maybe you could buy one of each and combine parts, but I suspect that
> > such weird hubs are probably made from scratch by tricking someone
> > like Chalo into running his lathe at midnight while uttering the
> > Lord's Prayer backwards.
>
> > Cheers,
>
> > Carl Fogel
>
> I don't want to fix the two "added" freewheels to both sides of the rear
> wheel at all. What I'm imagining is a way to functionally place them on
> a jackshaft, and then use the jackshaft to spin a conventional BB
> somehow--such as by using another cog and chain over the granny ring.
>
> This would be for a recumbent bike anyway, so the added drivetrain
> length wouldn't be a problem. I've only see this on a couple of IHPVA
> type streamliner recumbents--and not any of the current ones, so I don't
> suspect it's going to result in a higher power output.
>
> I am quite intrigued by a drivetrain that lets you use whatever stroke
> you wish. I suspect it would make the bicycle much less fit-critical,
> and may end up being more comfortable in use.
> ~

Why not forget about independent leg movement, and make one big pedal
for both feet? Kind of like a leg press machine. The drive train could
be simpler. Kind of like a stationary rowing machine.

Joseph

 

[Ben C]

On 2007-10-16, [email protected] <[email protected]> wrote:
[...]
> Why not forget about independent leg movement, and make one big pedal
> for both feet? Kind of like a leg press machine. The drive train could
> be simpler. Kind of like a stationary rowing machine.

Such things do exist. I passed someone once riding along on a recumbent
vehicle that was exactly that: a rowing machine bicycle.

He said he got it from the Netherlands.

Both the "pedals" that his feet were attached to and the handlebars were
attached to cables operating pulleys in some fashion, so he was pulling
back with his arms and pushing with his feet at the same time in an
authentic rowing action.

Here we are: http://www.rowingbike.com/main.php

I think it was one of those. Of course preferable to actual rowing
because you can see where you're going. It might be an idea to put one
in a boat connected to propellers...

 

[[email protected]]

On Oct 16, 1:13 pm, Ben C <[email protected]> wrote:
> On 2007-10-16, [email protected] <[email protected]> wrote:
> [...]
>
> > Why not forget about independent leg movement, and make one big pedal
> > for both feet? Kind of like a leg press machine. The drive train could
> > be simpler. Kind of like a stationary rowing machine.
>
> Such things do exist. I passed someone once riding along on a recumbent
> vehicle that was exactly that: a rowing machine bicycle.
>
> He said he got it from the Netherlands.
>
> Both the "pedals" that his feet were attached to and the handlebars were
> attached to cables operating pulleys in some fashion, so he was pulling
> back with his arms and pushing with his feet at the same time in an
> authentic rowing action.
>
> Here we are:http://www.rowingbike.com/main.php
>
> I think it was one of those. Of course preferable to actual rowing
> because you can see where you're going. It might be an idea to put one
> in a boat connected to propellers...

My vote is for a submarine.

Joseph

 

[Kerry Montgomery]

"DougC" <[email protected]> wrote in message
news:Ot%[email protected]...
> JeffWills wrote:
>
>>
>> Joe Kochanowski built a semi-linear drive recumbent, visible on this
>> page:
>> http://www.outsideconnection.com/gallant/hpv/joe/
>> with an action video at
>> http://www.outsideconnection.com/gallant/hpv/joe/linearDrive.mpg
>>
>> There's also the "K-drive":
>> http://web.uct.ac.za/depts/psychology/bok/kdrive.html
>>
>
> Neither of these allows variable-length pedal strokes, however. They are
> only variants based on conventional pedal cranks.
>
>> Various forms of linear drives have been tried in human-powered
>> vehicle competitions over the years. None has been successful. All of
>> the vehicles at this year's World Human Powered Speed Challenge used a
>> circular crank motion, even if other drivetrain details were all over
>> the place.
>>
>
> Power output is not my particular goal, riding comfort is--though I
> suspect that allowing variable-length strokes WOULD improve power output
> for most average riders. When people jog over varied terrain, they do not
> use the same stride length over all terrain, or even throughout the total
> distance--but conventional bicycles force you to use the same length of
> pedal stroke all the time.
>
> The Sherer trike approaches what I'm imagining, except that I don't have
> much interest in a trike, and I don't want to pay $4200+ for such a setup
> either.
>
> http://www.shererusa.com/page2.html
>
> What I'm interested is how exactly those freewheels have to be attached to
> function.
> ~

Hi DougC,
The freewheels just spin (thread) onto the BMX hub, a left-hand threaded
freewheel on the left side of the hub, and a right-handed freewheel on the
right side of the hub. Just like threading a nut onto a bolt.
If you use one of the double-sided BMX hubs that others have mentioned, just
spin the one of the appropriate freewheels on each side. Connect a chain to
the right side foot lever, run it over the top of the freewheel on the right
side of the hub, and connect the end of that chain to a spring that keeps
the chain taut when the foot lever is moving toward the hub. When the foot
lever is moving away from the hub, it will turn the hub. Do the same on the
left side.
Kerry