Seat Post Suspension

Seat Post Suspension

Post by Antonio A. Orti » Sun, 10 Dec 1995 04:00:00


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?

Antonio

 
 
 

Seat Post Suspension

Post by Mark Anthony Balz » Sun, 10 Dec 1995 04:00:00


Quote:
>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!

As I recall, you have to buy them to match your weight - so that the
preload is correct for you.  Otherwise it would be too stiff or too soft.

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).
Is that what a "muni" is?

Mark

 
 
 

Seat Post Suspension

Post by Roger Davie » Tue, 12 Dec 1995 04:00:00


Quote:

> >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 ***s like some MTB front forks.

Quote:
> 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.

Quote:
> 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
-----------------------------------------------

Cleveland
UK
-----------------------------------------------

 
 
 

Seat Post Suspension

Post by Beirne Konars » Wed, 13 Dec 1995 04:00:00

Quote:



>> >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 ***s 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

"Untouched by Scandal"          |       -- Francis Bacon

 
 
 

Seat Post Suspension

Post by Unicy.. » Thu, 14 Dec 1995 04:00:00


Quote:
>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?

I don't think they're as interested in springy jumps as they are in having a
softer ride.  Am I right?  After riding 36 miles on New York City roads on a
hard-*** tire big wheel you will try lots of things!

Somebody please build one of these, spend however much it costs, guinea-pig
it and tell us how it works out, okay?  Thanks.

In the States there seems to be a common fork on some of the Cannondale
mountain bikes that has a single shock at the top of the fork crown.  If
using a mountain bike suspension fork (instead of one made specifically for
seat posts), make sure it's adjustable so you can raise the stiffness.  The
bicycle's front fork is not made to support the entire weight of the rider,
and so a regular one would probably bottom out just by sitting on it.

John Foss

 
 
 

Seat Post Suspension

Post by Slavoj's b » Thu, 14 Dec 1995 04:00:00


[deletia re: suspension plans for munis]

Quote:

>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  

http://darkwing.uoregon.edu/~pdkittle  |       --Billy Bragg

 
 
 

Seat Post Suspension

Post by Magdalena Olimpia Tete » Fri, 15 Dec 1995 04:00:00

Hi John Foss.  I'm unicycling up here in Inwood?  Where are you?  Any
ideas where to get a giraffe here in NYC?

Shawn Hill.