bike feels spongy

"Javier" wrote: (clip)I've lost a total of 53 pounds since I started riding
last August(clip) I only feel it when I'm climbing in the saddle.
^^^^^^^^^^^^^^^^
I guess we can assume this bike does not have rear suspension.

Since you don't feel it while climbing out of the saddle, that seems to
point to the saddle or your butt. With every pedal stroke, as you push
down, you unweight the saddle. When you were heavier, this may have been
less noticeable. Just a theory.

Put 50 lbs of weight in your pockets, and see whether the problem goes away.
;-)

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

Javier

Do you have one of those seat stems with the spring in it?

"Javier" <[email hidden]> wrote in news:1153012287.811361.152160
@s13g2000cwa.googlegroups.com:

Quoted message said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

Javier

This is a little spooky, as the same thing happened to me a few days ago.

It felt so pronounced that I reached under the seat to see if the main nut
was only finger-tight.

I went back checked out the seat rails, and where they embed into the seat,
to make sure there was no failure there. I also fully inflated the tires
again.

And then, today, with about 200% humidity and 87F, I went out and viola, no
shimmy. That was even after clicking up a gear at the end of the climb.

So, there was a lot more perspiration and correctly inflated tires along
with newly laundered riding shorts.

What kind of saddle do you use? Does it have a leather cover, and what
about the shorts? The friction force depends on the normal forces and the
coefficient of friction, so you've got the whole set of empirical
parameters for the coefficient to consider, in addition to the dynamic
factors that could change the normal force.

I have noticed a lot more seat flexing since changing from a Terry CrMo to
a Zero-Y, but that seemed directly attributable to the seat change.

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

I think wvantwiller is onto the likely cause. The effect of a
slightly loose seatpost clamp will be a "sponginess" (or something
that could well be described with that term, at least). Just grab the
nose and tail of your saddle (not while you're riding though...) and
give it some back/forth and up/down pressure to see if you feel ANY
play (other than the normal flex in the rails).

If you don't see anything there, you might take a close look at your
frame - particularly the chain stays and the seat tube in the bottom
bracket region. Look for cracked paint as an indication of a problem.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Javier ha scritto:

Everything is

Quoted message said:

tight and nothing seems cracked or loose.

It might be the seat/saddle itself. It might be cracking, ready to
leave you in a rather uncomfortable state away from home.

Sergio
Pisa

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

Examine the frame for cracks.

Quoted message said:

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I
can't tell if the sponginess is coming from my saddle or rear tire
but I only feel it when I'm climbing in the saddle.

Have you changed your tire(s)? A higher-quality tire can give the illusion
of sponginess.

To confirm that it really is spongy, add water to the rear end and see if
the bike absorbs it. *rimshot*

--
Phil Lee, Squid

Per Phil Lee, Squid:

Quoted message said:

Examine the frame for cracks.

I didn't want to say it.... but the one time my bike started feeling what I'd
call "spongy", the frame had cracked at the rear dropout.
--
PeteCresswell

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

Javier

Hi,

As others have indicated, the cracked frame theory is definitely worth
checking. The only strange thing here is that you notice the flex only
when in the saddle, not when out of the saddle.

About 20 years ago I broke a frame made of Ishiwata 017 at the join
between seat tube and BB, left-hand side. I recall that the sponginess
was more apparent when in the saddle, maybe because the saddle pressed
less against the left thigh when pushing on the left crank due to the
cracked tube. But who knows, so many years down the road ...

Another possibility - do you have spokes loose on your rear wheel?

Most importantly though, congratulations on being able to get rid of 53
pounds in just under a year. That's a fine performance. And if your
frame is indeed cracked, let's hope it's an old one so that you can feel
you're rewarding yourself for your fitness efforts, by buying a nice
replacement.

Cheers, Robert

Quoted message said:

Javier ha scritto:

Everything is

Quoted message said:

tight and nothing seems cracked or loose.

It might be the seat/saddle itself. It might be cracking, ready to
leave you in a rather uncomfortable state away from home.

Sergio
Pisa

Good point. I cracked a Selle Italia saddle two years ago, but I just
figured it felt "unusually comfortable". But I did replace it the day
after . . . /Robert

"Robert" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle. Javier

++ snip ++

Quoted message said:

Most importantly though, congratulations on being able to get rid of 53

pounds in just under a year. That's a fine performance. And if your frame
is indeed cracked, let's hope it's an old one so that you can feel you're
rewarding yourself for your fitness efforts, by buying a nice replacement.

Cheers, Robert

Ditto on the congrats!

Someone else might have thought of this and I missed it, but...

If you have a sprung seat post, maybe the "heavier you" bottomed out the
spring. Now, with you being 53 pounds lighter, the spring can do its thing
and provide some springiness.

Jerry

"Ohio Jerry" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Robert" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a

bit

Quoted message said:

Quoted message said:

Quoted message said:

when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August

so

Quoted message said:

Quoted message said:

Quoted message said:

I'm not sure if what I'm feeling is also due to my weight loss. I

can't

Quoted message said:

Quoted message said:

Quoted message said:

tell if the sponginess is coming from my saddle or rear tire but I

only

Quoted message said:

Quoted message said:

Quoted message said:

feel it when I'm climbing in the saddle. Javier

++ snip ++

Quoted message said:

Most importantly though, congratulations on being able to get rid

of 53

Quoted message said:

Quoted message said:

pounds in just under a year. That's a fine performance. And if your

frame

Quoted message said:

Quoted message said:

is indeed cracked, let's hope it's an old one so that you can feel

you're

Quoted message said:

Quoted message said:

rewarding yourself for your fitness efforts, by buying a nice

replacement.

Quoted message said:

Quoted message said:

Cheers, Robert

Ditto on the congrats!

Someone else might have thought of this and I missed it, but...

If you have a sprung seat post, maybe the "heavier you" bottomed out

the

Quoted message said:

spring. Now, with you being 53 pounds lighter, the spring can do its

thing

Quoted message said:

and provide some springiness.

Jerry

One other issue that hasn't been touched on is your increased strength.
I've stopped riding for various reasons a number of times over the
years. I found that several frames felt "soft" after I got back in
condition, especially when climbing.

When honking out of the saddle, it can be hard to notice a problem
unless it's severe. As someone else said, check your spoke tension.

Chas.

Hey guys,

I have a feeling it maybe my saddle. It's a Koobi saddle and it does
seem a bit soft as of late, maybe it's time for a stiffer saddle. No
cracks anywhere on the frame or saddle.

Thanks for the congrats on the 53 lb drop, I've been working my ass
off...

Robert said:

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

Javier

Hi,

As others have indicated, the cracked frame theory is definitely worth
checking. The only strange thing here is that you notice the flex only
when in the saddle, not when out of the saddle.

About 20 years ago I broke a frame made of Ishiwata 017 at the join
between seat tube and BB, left-hand side. I recall that the sponginess
was more apparent when in the saddle, maybe because the saddle pressed
less against the left thigh when pushing on the left crank due to the
cracked tube. But who knows, so many years down the road ...

Another possibility - do you have spokes loose on your rear wheel?

Most importantly though, congratulations on being able to get rid of 53
pounds in just under a year. That's a fine performance. And if your
frame is indeed cracked, let's hope it's an old one so that you can feel
you're rewarding yourself for your fitness efforts, by buying a nice
replacement.

Cheers, Robert

Javier said:

Hey guys,

I have a feeling it maybe my saddle. It's a Koobi saddle and it does
seem a bit soft as of late, maybe it's time for a stiffer saddle. No
cracks anywhere on the frame or saddle.

Thanks for the congrats on the 53 lb drop, I've been working my ass
off...

Sounds more like "biking" your ass off. Kudos...

Quoted message said:

Robert said:

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

Javier

Hi,

As others have indicated, the cracked frame theory is definitely worth
checking. The only strange thing here is that you notice the flex only
when in the saddle, not when out of the saddle.

About 20 years ago I broke a frame made of Ishiwata 017 at the join
between seat tube and BB, left-hand side. I recall that the sponginess
was more apparent when in the saddle, maybe because the saddle pressed
less against the left thigh when pushing on the left crank due to the
cracked tube. But who knows, so many years down the road ...

Another possibility - do you have spokes loose on your rear wheel?

Most importantly though, congratulations on being able to get rid of 53
pounds in just under a year. That's a fine performance. And if your
frame is indeed cracked, let's hope it's an old one so that you can feel
you're rewarding yourself for your fitness efforts, by buying a nice
replacement.

Cheers, Robert

I think it's the saddle and may reward myself by buying s stiffer
saddle. I'd love to reward myself by buying a new Trek 5200 or Cervelo
Soloist Carbon, but my trusty Trek 1200 is less than a year old and it
helped me shave off those 53 pounds (and counting) so I can't bear to
retire it to a lonely life on the trainer.

Robert said:

Javier said:

Last week during my usual climbing ride the rear of my bike felt
"spongy" in other words I felt as if the rear of my bike sinking a bit
when I put force on the pedals. I got off checked my tires and they
were properly inflated (I pump up before every ride). Everything is
tight and nothing seems cracked or loose.

I've lost a total of 53 pounds since I started riding last August so
I'm not sure if what I'm feeling is also due to my weight loss. I can't
tell if the sponginess is coming from my saddle or rear tire but I only
feel it when I'm climbing in the saddle.

Javier

Hi,

As others have indicated, the cracked frame theory is definitely worth
checking. The only strange thing here is that you notice the flex only
when in the saddle, not when out of the saddle.

About 20 years ago I broke a frame made of Ishiwata 017 at the join
between seat tube and BB, left-hand side. I recall that the sponginess
was more apparent when in the saddle, maybe because the saddle pressed
less against the left thigh when pushing on the left crank due to the
cracked tube. But who knows, so many years down the road ...

Another possibility - do you have spokes loose on your rear wheel?

Most importantly though, congratulations on being able to get rid of 53
pounds in just under a year. That's a fine performance. And if your
frame is indeed cracked, let's hope it's an old one so that you can feel
you're rewarding yourself for your fitness efforts, by buying a nice
replacement.

Cheers, Robert