Need to put togethere a dual hub

Jimmy said:

Any idea how I could fabricate a dual hub?
I need a single sprocket freeewheel on the left and a single freewheel
sprocket on the right.
Doesn't have to look nice, but I need it to be cheap.
I've been thinking about this for days , but haven't figured it out.

Buy one. Anything fixed/free or fixed/fixed will do you right, since a
single speed freewheel will screw onto the threads for the track cog if
you want. It won't be cheap, though, especially considering the cost of
two single speed freewheels. But it will be cheaper and work better than
screwing around trying to fabricate something from existing cassette hubs.

Jasper

Jimmy said:

Any idea how I could fabricate a dual hub?

Do you mean a flip-flop hub?

http://www.sheldonbrown.com/harris/fixed-hubs.html

Jasper Janssen said:

Jimmy said:

Any idea how I could fabricate a dual hub?
I need a single sprocket freeewheel on the left and a single freewheel
sprocket on the right.
Doesn't have to look nice, but I need it to be cheap.
I've been thinking about this for days , but haven't figured it out.

Quoted message said:

Buy one. Anything fixed/free or fixed/fixed will do you right, since a
single speed freewheel will screw onto the threads for the track cog if
you want. It won't be cheap, though, especially considering the cost of
two single speed freewheels. But it will be cheaper and work better than
screwing around trying to fabricate something from existing cassette hubs.

But the freewheel on the left will spin backwards... unless you get a
left-side drive (LSD) freewheel.

Get a flip-flop hub, one normal freewheel, and one left side drive
freewheel. Bob's your uncle.

--
Dave
dvt at psu dot edu

dvt said:

Quoted message said:

Quoted message said:

Any idea how I could fabricate a dual hub?

Quoted message said:

Quoted message said:

Buy one. Anything fixed/free or fixed/fixed will do you right, since a
single speed freewheel will screw onto the threads for the track cog if
you want. It won't be cheap, though, especially considering the cost of
two single speed freewheels. But it will be cheaper and work better than
screwing around trying to fabricate something from existing cassette
hubs.

Quoted message said:

But the freewheel on the left will spin backwards... unless you get a
left-side drive (LSD) freewheel.

Get a flip-flop hub, one normal freewheel, and one left side drive
freewheel. Bob's your uncle.

I saw a wheel like this last week, used in a bicycle with a stepper
mechanism instead of rotary cranks. The (longer than normal) cranks were
attached to levers, that had chains attached to them. The point of
attachment of the chain to the lever set the gearing of the bicycle.
When the crank was depressed, the lever pulled the chain, which pulled
the hub. Also a run of chain around the seat-tube at the bb caused the
other pedal to rise when the first was depressed.

Both cranks were connected to the hub this way, on opposite sides, to
two freewheels arranged as you describe. Stepping with the right foot
drove the right sprocket, and stepping with the left the left. The bike
was in the LBS for repairs to the unusual drive train, and the mechanics
were getting creative. I think it was being ridden by someone with a
disability that made stepping easier than pedaling. Sure was a weird
bike to ride!

Jacobe Hazzard said:

I saw a wheel like this last week, used in a bicycle with a stepper
mechanism instead of rotary cranks.

The archives of this group show "winnobizi" proposing a patent on this
idea within the past few months. I wonder if you saw his bike.

--
Dave
dvt at psu dot edu

dvt said:

Jacobe Hazzard said:

I saw a wheel like this last week, used in a bicycle with a stepper
mechanism instead of rotary cranks.

The archives of this group show "winnobizi" proposing a patent on this
idea within the past few months. I wonder if you saw his bike.

Very much no, since winnobizi has no prototype, and these stepper bikes
have been made before (as in, 1890s-90s before). If you have the right
kind of disability, it may even make sense.

Jasper

Jacobe Hazzard said:

I saw a wheel like this last week, used in a bicycle with a stepper
mechanism instead of rotary cranks. The (longer than normal)
cranks were attached to levers, that had chains attached to them.
The point of attachment of the chain to the lever set the gearing
of the bicycle. When the crank was depressed, the lever pulled
the chain, which pulled the hub. Also a run of chain around the
seat-tube at the bb caused the other pedal to rise when the first
was depressed.

Quoted message said:

Both cranks were connected to the hub this way, on opposite sides,
to two freewheels arranged as you describe. Stepping with the right
foot drove the right sprocket, and stepping with the left the left.

Probably an Alenax:

http://www.classicrendezvous.com/images/bike%20shops/First_Flight/Alenax_closeup.JPG

http://www.trbsystems.com/Articles/pressrel1.htm

James Thomson