Other Suspension seatpost benefits?

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As I marveled at the silky smooth ride my suspension seatpost was
giving me, I started wondering ... what other benefits or liabilities
did it have on my bike.

The spring was absorbing the shock to my body. Was it absorbing
energy and relieving stress else where? Was it lessening the stress
on my frame and wheels by absorbing some of the weight of my body
slamming into the seat as I encountered bumps in the road? Or was it
causing more stress on the wheels since I was able to take those bumps
at a higher rate of speed due to the suspension seatpost?

I was just curious...

Any suspension reduces the shock of impact for everything--that's why
> they're called shock absorbers and let us go faster over bumps.
>
> As an analogy, a boxing glove protects both the fist and the skull.
>
> With a suspension post, the bicycle can be shoved upward against the
> enormous (m)ass resting on the seat and will encounter less resistance
> than normal. This is felt by the bicycle below the post as a smoother,
> less bumpy ride, just as the (m)ass above the seat post feels a
> delightfully improved smoothness.
>
> The shock absorber gets crushed from both top and bottom, absorbs the
> shock, and suffers in silence. It converts the energy of compression to
> heat and to re-expansion, but spreads the work out over a longer period,
> reducing the shock.
>
> Hitting a bump, the bike rises against the cushion of the suspension,
> compressing it, and then the suspension expands, belatedly shoving you
> upward more slowly and gently than a solid post. The spring action soaks
> up the jolt and slows it down, so both rider and bicycle benefit.
>
> Put a suspension device between the bicycle and the road (a pneumatic
> tire) and the same thing occurs--the jolts are softened.
>
> Or so I hear. I once had to finish a trials event with one rear shock
> unit bent at 90 degrees and never again said anything unkind about those
> rear shocks--darned useful devices.
>
> Carl Fogel
>

Cool.

Rocketman58

"rocketman58" <artisticwill@worldnet.att.net> wrote in message
news:70ce0d5a.0404072030.5ba94e85@posting.google.com...
> As I marveled at the silky smooth ride my suspension seatpost was
> giving me, I started wondering ... what other benefits or liabilities
> did it have on my bike.
>
> The spring was absorbing the shock to my body. Was it absorbing
> energy and relieving stress else where? Was it lessening the stress
> on my frame and wheels by absorbing some of the weight of my body
> slamming into the seat as I encountered bumps in the road?

Yes. But you can do the same thing more effectively by not riding like a sack
of potatoes.

> Or was it
> causing more stress on the wheels since I was able to take those bumps
> at a higher rate of speed due to the suspension seatpost?

No.

Suspension seats have been around since the bicycle has, most of them use
springs. The other low-tech solution is pneumatic tires, most of us use them.

.....Yes. But you can do the same thing more effectively by not riding
like a sack of potatoes....

Hmm, I don't ever remember riding like a sack of pototoes. After 25
year of hard core ridding, I have pretty good riding skills. But, at
46 years old, I'm not in the same shape as I used to be. In addition,
I have a few injuries from my MTB racing days. I pretty much stay
seated while riding now, and my bars are higher than seat due to an
old wrist injury. Thus the practical need for the suspension post.

.....Suspension seats have been around since the bicycle has, most of
them use springs...

modern suspension seats typically use elastomers (such as mine does).

.....The other low-tech solution is pneumatic tires, most of us use
them....

I guess that's why I running 26c wide tires on my road bike. Back in
the old days of MTB racing, letting some air out of our "pneumatic
tires" was the only form of suspension we had, other than relaxed
geometry frames. I never found Brooks type leather seats with springs
too practial for technical off road riding.

Rocketman58

RE/
>Yes. But you can do the same thing more effectively by not riding like a sack
>of potatoes.

Agreed, but it sure is nice to have that sus under you when the occasinal bump
sneaks up and you take inadvertantly it sitting.
--
PeteCresswell

"rocketman58" <artisticwill@worldnet.att.net> wrote in message
news:70ce0d5a.0404082135.7a685747@posting.google.com...
> ....Yes. But you can do the same thing more effectively by not riding
> like a sack of potatoes....
>
> Hmm, I don't ever remember riding like a sack of pototoes. After 25
> year of hard core ridding, I have pretty good riding skills. But, at
> 46 years old, I'm not in the same shape as I used to be.

Wow, that *is* old, maybe you should switch to golf.

> In addition,
> I have a few injuries from my MTB racing days. I pretty much stay
> seated while riding now, and my bars are higher than seat due to an
> old wrist injury. Thus the practical need for the suspension post.

My wife rides that way, so do many people (bars higher than seat), it doesn't
require suspension.

> ....Suspension seats have been around since the bicycle has, most of
> them use springs...
>
> modern suspension seats typically use elastomers (such as mine does).

Yeah, which makes them suck in cold weather. Most suspension seatposts have so
much stiction that they work worse than sprung saddles. The parallelogram ones
work much better. The only difference between elastomers and springs is that
the elastomers are supposed to provide some damping, in reality, they don't
provide very much.

> ....The other low-tech solution is pneumatic tires, most of us use
> them....
>
> I guess that's why I running 26c wide tires on my road bike.

I don't know what "26c" means.

> Back in
> the old days of MTB racing, letting some air out of our "pneumatic
> tires" was the only form of suspension we had, other than relaxed
> geometry frames.

You must have ridden pretty mellow courses not to pinch flat. I think the
suspension effect of "relaxed geometry" frames must have been imaginary.

> I never found Brooks type leather seats with springs
> too practial for technical off road riding.

A whole lot of people find sprung saddles practical for off-road riding,
especially back when on-road riding was the equivalent of off-roading today.

Suspension is the wave of the future, not just for confort but for
elite road athletes.

Those who claim that manliness decrees you must stand up and use your
legs as shock absorbers ignore the constant tension/waste of energy
needed to keep legs tensed to use them as shocks in all situations; as
well as those painful situations where you just don't see a potholein
time, don't stand up, and thus take a nasty shock to the spine..

I just did the Copperopolis road race today, total crap roads, and my
back would be wrecked w/o my suspension seatpost. But it's not just
because I'm a master's lard-muffin:DFL:

An 18 year old I met who rode at the national level is thinking of
getting one too. He said his back was so messed up after nationals he
couldn't walk.

The spine is not engineered to take constant direct hits like a racing
bike gives through the pelvis. Evolution designed the legs and feet to
proide this protection. But this is at cross purposes with using them
to pedal. Your back tenses up in response to the continued
microtraumas.

I believe chronic tensing of the muscles wastes energy, my guess is
the realization of this will result in professional cyclists starting
to use shock posts in about 2-4 years as research emerges. It will
take a leader beating the others like LeMond beat Fignon with aero
bars to remove the sissy stigma.

RE/
>I believe chronic tensing of the muscles wastes energy,

Speaking as somebody at the low end of the strength-endurance curve, I perceive
a huge difference between riding my hard-tail and my FS - same tires, same
terrain, same wasted body.

Traction is not a factor here because I don't normally put out enough horsepower
for the FS advantage to kick in traction/control-wise. It's just the diff
between having to use the legs to protect the butt/back and not having to.

I still like the FS for the variety, for the responsiveness, and because it
forces me to make my legs take a more active role in shock absorbtion...but the
calories required to cover the same distance is definately higher without
suspension - even when only riding uneven pavement or rough gravel.

My guess is that the same holds for sus post vs rigid.
--
PeteCresswell

artisticwill@worldnet.att.net (rocketman58) wrote in message news:<70ce0d5a.0404082135.7a685747@posting.google.com>...
>> ....The other low-tech solution is pneumatic tires, most of us use
> them....
>
> I guess that's why I running 26c wide tires on my road bike. Back in
> the old days of MTB racing, letting some air out of our "pneumatic
> tires" was the only form of suspension we had, other than relaxed
> geometry frames. I never found Brooks type leather seats with springs
> too practial for technical off road riding.
>
Interesting, what pressure are you running these 700x26 tires? A few
years ago I went from 700x23 @ 120psi to 25-26mm wide tires and
running them at a lower psi, e.g., 100-110psi, I found the comfort
level to improve dramatically, without sacrificing any performance. In
fact, the 700x25 tires I'm using seem to perform *better* than the old
700x23. I won't use any smaller than a 700x25. If you need more
*comfort*/shock absorption, make sure you have been properly fitted on
your bike. If that doesn't work, a suspension seatpost may be your
only choice. Good Luck!

.... Interesting, what pressure are you running these 700x26 tires? A
few
> years ago I went from 700x23 @ 120psi to 25-26mm wide tires and
> running them at a lower psi, e.g., 100-110psi, I found the comfort
> level to improve dramatically, without sacrificing any performance. In
> fact, the 700x25 tires I'm using seem to perform *better* than the old
> 700x23. I won't use any smaller than a 700x25. If you need more
> *comfort*/shock absorption, make sure you have been properly fitted on
> your bike. If that doesn't work, a suspension seatpost may be your
> only choice. Good Luck!

I have only run 700x25 or 28 tires. When I switched from sew-ups 25
years ago, 700x25 was the typical size available. By the time thin
higher pressure tires came into fashion, I no longer had a road bike,
and was only riding off road.

I still remember the silky smooth ride of a pair of 700x25 Specialized
127tpi Turbo tires mounted on a pair of MA40 rims. I was probably
running around 100psi. But, to answer your question: I am running a
pair of Specialized 700x26 tires at around 105psi. My choice was
based on comfort as well as practicality. The roads where I live are
often not in the best condition. I have test ridden a few bikes with
700x23 tires, but I prefer a minimum of 25.

As far a bike fit, that's not a problem. I'm riding a hand made
Reynolds 631 frame with a carbon fork. I'ts the most comfortable road
frame I have ever ridden. (Ok, it is not any where as comfortable as
a few of the recumbents I have owned in the past. Interstingly on
some recumbents, wider tires often out perform narrow ones. But that's
another story) .

Hope this helps.


PS - I broke one of my rules with a previous poster: Never argue
with someone who makes assumptions or sweeping generalizations.

I have been riding off road for over 28 years. I have covered much of
the front range of the San Gabriel Mts and other areas, riding many
trails many wouldn't dream of. During that time, I have only had one
pintch-flat. And, only then because I was careless. In my
experience, if you know how to ride and how to set up your bike, you
don't need to worry about pintch flats.