Forward only drive "standard" unicycle

Jason Richards <> wrote:

>Consider a wheel with a chain ring that is fixed only in the forward direction,
>but will freewheel when spun backwards (i.e. much like that of an uggg… 10
>speed bicycle wheel with only the lowest gear) and assume that this wheel has a
>drum brake or a coaster brake (i.e. within the hub).

I have a forward only drive “standard” unicycle. Tom Miller and I built it
together a few years ago.

It has a two piece hub which allows the pedals to be stopped while the wheel
continues to move forward. There are two bearings between the hub shell and the
bare 5/8" axle. One is a normal bearing. The other is a clutch bearing which
allows the bearing to turn in one direction and bind (lock tight) in the other

When pedaled forward, the clutch bearing binds and the axle - hub shell turn
together providing forward thrust or power. When pedaled backward, the clutch
bearing unbinds allowing the axle and hub shell to move independently.

The pedals can be stopped in a horizontal position and the cycle can be coasted
in this position with the feet remaining on the pedals.

>If I wanted to race down a VERY LARGE hill, then I (theoretically) should
>be able to stop pedaling forward, ease back on the brake (assume that the
>brake was engaged when back pedaling) and control my decent (and balance)
>in this manner.

My forward only drive “standard” unicycle has no brakes, but a caliper brake
could easily be added. Maybe some sort of drum brake activated by back pedaling,
but that could affect balance adversely perhaps.

>Is it possible to ride such a uni with only forward drive?

Yes, but without a brake, the only way to deaccelerate is to coast until
momentum is consumed by air and road friction. (Then pedal forward to accelerate
again, etc.)


Ken Fuchs <