Re: Seat Post Suspension

[Roger Davies]

On 9 Dec 1995, Mark Anthony Balzer wrote:

> "Antonio A. Ortiz" <aao4247@acs.tamu.edu> writes:
> >I was at a bike shop the other day and I saw a seat post with suspension. Has
> >anyone ever had a suspensioned Uni? Or is it not a good Idea?
>
> I rode a bicycle with a suspension seat post (I think it was a "gas-spring"
> like the ones used on car hatchbacks - they are preloaded by gas pressure so
> they don't move until you exceed the preload - then it is like a
> spring/damper.... Anyway, the point is IT WAS INCREDIBLE!!!!! I would have
> run right out and gotten 2 for my tandem, except that they're not made in the
> same small diameter as my Schwinn seat post tube. Uhhhh, and they are over
> $100 each!

This has been discussed among several of the mountain uni brigade, and we are
all very interested to know if they would take the hammering. Some of the makes
have a reputation for exploding! and others for twisting slightly. Both features
are not desirable. We believe that it would work superbly but none of us have
had the guts to try it yet. We believe that thet main problem is that uni's have
a lot more rotation on the seat than there is on a MTB seat. There are several
different types that vary in cost considerably from GBP 25 to GBP 200, the cheap
ones use elastomer rubbers like some MTB front forks.

> Use one on a uni? It would probably work. I often wondered about building a
> uni with a mountian-bike fork (the kind with shocks).

If you intend to use the standard fork legs I think you will have problems with
the two legs not moving together (MTB bikes have this problem and it will be
worse with uni's). If you are very serious about trying talk to ActionTEC who
are based south of LA and talk to Russ, He is a great guy and would be game. His
forks use a ridgid fork leg and a single hydraulic damper (similar to Browns in
the UK)in what would be our seat post. If anyone does get in touch with him say
"hi" from me.

> Is that what a "muni" is?

No the muni is basically a modified Pashley, the Carrbon Fibre Uni is similar as
it uses a Pace fork crown.

Rgr
-----------------------------------------------
Roger.Davies@octacon.co.uk Cleveland UK
-----------------------------------------------

[Beirne Konarski]

"Roger Davies" <Roger.Davies@octacon.co.uk> writes:

>On 9 Dec 1995, Mark Anthony Balzer wrote:

>> "Antonio A. Ortiz" <aao4247@acs.tamu.edu> writes:
>> >I was at a bike shop the other day and I saw a seat post with suspension.
>> >Has anyone ever had a suspensioned Uni? Or is it not a good Idea?
>>
>> I rode a bicycle with a suspension seat post (I think it was a "gas-spring"
>> like the ones used on car hatchbacks - they are preloaded by gas pressure so
>> they don't move until you exceed the preload - then it is like a
>> spring/damper.... Anyway, the point is IT WAS INCREDIBLE!!!!! I would have
>> run right out and gotten 2 for my tandem, except that they're not made in the
>> same small diameter as my Schwinn seat post tube. Uhhhh, and they are over
>> $100 each!

>This has been discussed among several of the mountain uni brigade, and we are
>all very interested to know if they would take the hammering. Some of the makes
>have a reputation for exploding! and others for twisting slightly. Both
>features are not desirable. We believe that it would work superbly but none
of
>us have had the guts to try it yet. We believe that thet main problem is that
>uni's have a lot more rotation on the seat than there is on a MTB seat. There
>are several different types that vary in cost considerably from GBP 25 to GBP
>200, the cheap ones use elastomer rubbers like some MTB front forks.

>> Use one on a uni? It would probably work. I often wondered about building a
>> uni with a mountian-bike fork (the kind with shocks).

>If you intend to use the standard fork legs I think you will have problems
with
>the two legs not moving together (MTB bikes have this problem and it will be
>worse with uni's). If you are very serious about trying talk to ActionTEC who
>are based south of LA and talk to Russ, He is a great guy and would be game.
>His forks use a ridgid fork leg and a single hydraulic damper (similar to
>Browns in the UK)in what would be our seat post. If anyone does get in touch
>with him say "hi" from me.

I'm a bit stumped here. Shocks make sense in a bicycle fork because they go
between the frame and the wheels. On a unicycle the effect would seem to be that
the seat would go down when landing or hitting a bump, requiring more leg effort
to pedal, since your knees would be bent more. If the goal is to have springy
shocks to help with jumps, this won't work because the crank is part of the
wheel, not the frame. What am I missing here?

Thanks, Beirne

--
-------------------------------------------------------------------------------
Beirne Konarski | Reading maketh a full man, conference a beirnek@summitis.com |
ready man, and writing an exact man. "Untouched by Scandal" | -- Francis Bacon

[Slavoj's boy]

In article <4ak7u4$cce@news.roadway.com>, Beirne Konarski <beirnek@summitis.COM>
wrote: [deletia re: suspension plans for munis]
>
>I'm a bit stumped here. Shocks make sense in a bicycle fork because they go
>between the frame and the wheels. On a unicycle the effect would seem to be
>that the seat would go down when landing or hitting a bump, requiring more leg
>effort to pedal, since your knees would be bent more. If the goal is to have
>springy shocks to help with jumps, this won't work because the crank is part of
>the wheel, not the frame. What am I missing here?
>
>Thanks, Beirne

I've been thinking about making a uni with a suspension fork for quite a while.
The concern you raise above is valid, to a point. Mountain bikes which are
suspended come in various designs, one of which suspends the entire drivetrain
from a pivot near the bottom bracket. This design has the benefit of acting like
a nonsuspended bike when the rider stands up. I think that the uni I want to
make will be the same in that it will absorb some of the shock on my body while
maintaining positive pedal action. Regarding the bending of the knees--I can't
see it as that much of a problem. If my mountain bike's suspension fork is a
reliable indicator, it doesn't stay compressed for long--maybe half a
second--plus the average travel is only around 2", which I doubt would throw
one's stride off by too much.

The way I see it, a suspended uni would do the same thing a suspended bike
does--allow you to ride farther/faster with less fatigue.

Now, if I could just figure out how to make the hub ...

Peter
--
`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`'`' Peter
Kittle, dogsbody | "The revolution is just pdkittle@darkwing.uoregon.edu | a
t-shirt away." http://darkwing.uoregon.edu/~pdkittle | --Billy Bragg